text:
/Users/chl/Dropbox/Papers/Revicki-1997-Qual%20Life%20Res_Health%20status%20assess.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p6788},
rating = {0}
}

@article{Hill:2007p7864,
author = {Cheryl D Hill and Michael C Edwards and David Thissen and Michelle M Langer and R J Wirth and Tasha M Burwinkle and James W Varni},
journal = {Med Care},
title = {Practical issues in the application of item response theory: a demonstration using items from the pediatric quality of life inventory (PedsQL) 4.0 generic core scales},
abstract = {BACKGROUND: Item response theory (IRT) is increasingly being applied to health-related quality of life instrument development and refinement. This article discusses results obtained using categorical confirmatory factor analysis (CCFA) to check IRT model assumptions and the application of IRT in item analysis and scale evaluation. OBJECTIVES: To demonstrate the value of CCFA and IRT in examining a health-related quality of life measure in children and adolescents. METHODS: This illustration uses data from 10,241 children and their parents on items from the 4 subscales of the PedsQL 4.0 Generic Core Scales. CCFA was applied to confirm domain dimensionality and identify possible locally dependent items. IRT was used to assess the strength of the relationship between the items and the constructs of interest and the information available across the latent construct. RESULTS: CCFA showed generally strong support for 1-factor models for each domain; however, several items exhibited evidence of local dependence. IRT revealed that the items generally exhibit favorable characteristics and are related to the same construct within a given domain. We discuss the lessons that can be learned by comparing alternate forms of the same scale, and we assess the potential impact of local dependence on the item parameter estimates. CONCLUSIONS: This article describes CCFA methods for checking IRT model assumptions and provides suggestions for using these methods in practice. It offers insight into ways information gained through IRT can be applied to evaluate items and aid in scale construction.},
affiliation = {RTI Health Solutions, Research Triangle Park, North Carolina 27709-2194, USA. cdhill@rti.org},
number = {5 Suppl 1},
pages = {S39--47},
volume = {45},
year = {2007},
month = {May},
language = {eng},
keywords = {Pediatrics, Humans, Self Disclosure, Questionnaires, Quality of Life, Adolescent, Proxy, Child, Models: Theoretical, Health Status},
date-added = {2010-03-20 19:00:26 +0100},
date-modified = {2010-07-29 19:39:29 +0200},
doi = {10.1097/01.mlr.0000259879.05499.eb},
pii = {00005650-200705001-00006},
pmid = {17443118},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Hill-2007-Med%20Care_Practical%20issues%20in.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p7864},
rating = {0}
}

@article{Mitchell:2004p5960,
author = {C G Mitchell and S L Bowker and S R Majumdar and E L Toth and J A Johnson},
journal = {CANADIAN JOURNAL OF DIABETES},
title = {Lack of Correlation Between Patient-reported Outcomes and Glycemic Control in Type 2 Diabetes Not Managed by Insulin},
abstract = {OBJECTIVE
The objective of this study was to investigate the relationship between glycemic control and patient-reported health status and self-monitoring of blood glucose (SMBG) in people with type 2 diabetes mellitus not managed by insulin.
METHOD
Sociodemographic and clinical data were collected from patients recruited through community pharmacies. Glycosylated hemoglobin (A1C) was assessed in a central laboratory; patients themselves completed the Summary of Diabetes Self-care Activities (SDSCA) and the RAND-12 Health Status Inventory.
RESULTS
Patients (n=434) reported a mean duration of diabetes of 7.8$\pm$6.9 years and had a mean A1C of 7.3$\pm$1.3%. The Pearson correlation for all levels of glycemic control (as measured by A1C) and SDSCA SMBG scores was --0.05 (p=0.34). Neither physical (r=0.05, p=0.31) nor mental (r=--0.01, p=0.84) health status was associated with A1C.},
number = {4},
pages = {362--368},
volume = {28},
year = {2004},
date-added = {2010-02-18 23:25:47 +0100},
date-modified = {2010-02-18 23:27:21 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Mitchell-2004-CANADIAN%20JOURNAL%20OF%20DIABETES_Lack%20of%20Correlation.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p5960},
rating = {0}
}

@article{Hettema:2005p2902,
author = {John M Hettema and Carol A Prescott and John M Myers and Michael C Neale and Kenneth S Kendler},
journal = {Arch Gen Psychiatry},
title = {The structure of genetic and environmental risk factors for anxiety disorders in men and women},
abstract = {BACKGROUND: The anxiety disorders exhibit high levels of lifetime comorbidity with one another. Understanding the underlying causes of this comorbidity can provide insight into the etiology of the disorders and inform classification and treatment. OBJECTIVE: To explain anxiety disorder comorbidity by examining the structure of the underlying genetic and environmental risk factors. DESIGN: Lifetime diagnoses for 6 anxiety disorders (generalized anxiety disorder, panic disorder, agoraphobia, social phobia, animal phobia, and situational phobia) were obtained during personal interviews from a population-based twin registry. Multivariate structural equation modeling that allowed for sex differences was performed. SETTING: General community sample. PARTICIPANTS: More than 5000 members of male-male and female-female twin pairs from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders. MAIN OUTCOME MEASURES: Parameter estimates for best-fitting model. RESULTS: The full model, which contained 2 common genetic, shared environmental, and unique environmental factors plus disorder-specific factors, could be constrained to equality across male and female study participants. In the best-fitting model, the genetic influences on anxiety were best explained by 2 additive genetic factors common across the disorders. The first loaded most strongly in generalized anxiety disorder, panic disorder, and agoraphobia, whereas the second loaded primarily in the 2 specific phobias. Social phobia was intermediate in that it was influenced by both genetic factors. A small role for shared environmental influences was observed owing to a single common factor that accounted for less than 12% of the total variance for any disorder. Unique environmental influences could be explained by a single common factor plus disorder-specific effects. CONCLUSIONS: The underlying structure of the genetic and environmental risk factors for the anxiety disorders is similar between men and women. Genes predispose to 2 broad groups of disorders dichotomized as panic-generalized-agoraphobic anxiety vs the specific phobias. The remaining associations between the disorders are largely explained by a unique environmental factor shared across the disorders and, to a lesser extent, a common shared environmental factor.},
affiliation = {Virginia Institute for Psychiatry and Behavioral Genetics and Department of Psychiatry, Virginia Commonwealth University, Richmond, USA. jhettema@hsc.vcu.edu <jhettema@hsc.vcu.edu>},
number = {2},
pages = {182--9},
volume = {62},
year = {2005},
month = {Feb},
language = {eng},
keywords = {Models: Genetic, Genetic Predisposition to Disease, Anxiety Disorders, Sex Factors, Twins: Monozygotic, Diseases in Twins, Twins: Dizygotic, Social Environment, Virginia, Family Health, Humans, Models: Statistical, Registries, Risk Factors, Male, Female, Comorbidity, Psychiatric Status Rating Scales, Adult},
date-added = {2010-01-13 15:00:42 +0100},
date-modified = {2010-01-13 15:00:42 +0100},
doi = {10.1001/archpsyc.62.2.182},
pii = {62/2/182},
pmid = {15699295},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p2902},
rating = {0}
}

@article{Johnston:2009p6403,
author = {Michael F Johnston and Ron D Hays and Ka-Kit Hui},
journal = {BMC Complement Altern Med},
title = {Evidence-based effect size estimation: an illustration using the case of acupuncture for cancer-related fatigue},
abstract = {BACKGROUND: Estimating a realistic effect size is an important issue in the planning of clinical studies of complementary and alternative medicine therapies. When a minimally important difference is not available, researchers may estimate effect size using the published literature. This evidence-based effect size estimation may be used to produce a range of empirically-informed effect size and consequent sample size estimates. We provide an illustration of deriving plausible effect size ranges for a study of acupuncture in the relief of post-chemotherapy fatigue in breast cancer patients. METHODS: A PubMed search identified three uncontrolled studies reporting the effect of acupuncture in relieving fatigue. A separate search identified five randomized controlled trials (RCTs) with a wait-list control of breast cancer patients receiving standard care that reported data on fatigue. We use these published data to produce best, average, and worst-case effect size estimates and related sample size estimates for a trial of acupuncture in the relief of cancer-related fatigue relative to a wait-list control receiving standard care. RESULTS: Use of evidence-based effect size estimation to calculate sample size requirements for a study of acupuncture in relieving fatigue in breast cancer survivors relative to a wait-list control receiving standard care suggests that an adequately-powered phase III randomized controlled trial comprised of two arms would require at least 101 subjects (52 per arm) if a strong effect is assumed for acupuncture and 235 (118 per arm) if a moderate effect is assumed. CONCLUSION: Evidence-based effect size estimation helps justify assumptions in light of empirical evidence and can lead to more realistic sample size calculations, an outcome that would be of great benefit for the field of complementary and alternative medicine.},
affiliation = {Center for East-West Medicine, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA. johnston@ucla.edu},
pages = {1},
volume = {9},
year = {2009},
month = {Jan},
language = {eng},
keywords = {Acupuncture Therapy, Analysis of Variance, Humans, Evidence-Based Medicine, Clinical Trials as Topic, Fatigue, Research Design, Data Interpretation: Statistical, Sample Size, Complementary Therapies, Breast Neoplasms, Regression Analysis},
date-added = {2010-02-23 08:26:03 +0100},
date-modified = {2010-02-23 08:26:03 +0100},
doi = {10.1186/1472-6882-9-1},
pii = {1472-6882-9-1},
pmid = {19144128},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p6403},
rating = {0}
}

@article{IonitaLaza:2007p3858,
author = {Iuliana Ionita-Laza and Matthew B McQueen and Nan M Laird and Christoph Lange},
journal = {Am J Hum Genet},
title = {Genomewide weighted hypothesis testing in family-based association studies, with an application to a 100K scan},
abstract = {For genomewide association (GWA) studies in family-based designs, we propose a novel two-stage strategy that weighs the association P values with the use of independently estimated weights. The association information contained in the family sample is partitioned into two orthogonal components--namely, the between-family information and the within-family information. The between-family component is used in the first (i.e., screening) stage to obtain a relative ranking of all the markers. The within-family component is used in the second (i.e., testing) stage in the framework of the standard family-based association test, and the resulting P values are weighted using the estimated marker ranking from the screening step. The approach is appealing, in that it ensures that all the markers are tested in the testing step and, at the same time, also uses information from the screening step. Through simulation studies, we show that testing all the markers is more powerful than testing only the most promising ones from the screening step, which was the method suggested by Van Steen et al. A comparison with a population-based approach shows that the approach achieves comparable power. In the presence of a reasonable level of population stratification, our approach is only slightly affected in terms of power and, since it is a family-based method, is completely robust to spurious effects. An application to a 100K scan in the Framingham Heart Study illustrates the practical advantages of our approach. The proposed method is of general applicability; it extends to any setting in which prior, independent ranking of hypotheses is available.},
affiliation = {Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA. iionita@hsph.harvard.edu},
number = {3},
pages = {607--14},
volume = {81},
year = {2007},
month = {Sep},
language = {eng},
keywords = {Genetic Markers, Genome: Human, Quantitative Trait: Heritable, Genetic Predisposition to Disease, Polymorphism: Single Nucleotide, Gene Frequency, Humans, Genetic Testing, Linkage (Genetics)},
date-added = {2010-01-16 21:02:32 +0100},
date-modified = {2010-01-16 21:02:32 +0100},
doi = {10.1086/519748},
pii = {S0002-9297(07)61357-3},
pmid = {17701906},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p3858},
rating = {0}
}

@article{Enard:2010p5367,
author = {David Enard and Frantz Depaulis and Hugues Roest Crollius},
journal = {PLoS Genet},
title = {Human and non-human primate genomes share hotspots of positive selection},
abstract = {Among primates, genome-wide analysis of recent positive selection is currently limited to the human species because it requires extensive sampling of genotypic data from many individuals. The extent to which genes positively selected in human also present adaptive changes in other primates therefore remains unknown. This question is important because a gene that has been positively selected independently in the human and in other primate lineages may be less likely to be involved in human specific phenotypic changes such as dietary habits or cognitive abilities. To answer this question, we analysed heterozygous Single Nucleotide Polymorphisms (SNPs) in the genomes of single human, chimpanzee, orangutan, and macaque individuals using a new method aiming to identify selective sweeps genome-wide. We found an unexpectedly high number of orthologous genes exhibiting signatures of a selective sweep simultaneously in several primate species, suggesting the presence of hotspots of positive selection. A similar significant excess is evident when comparing genes positively selected during recent human evolution with genes subjected to positive selection in their coding sequence in other primate lineages and identified using a different test. These findings are further supported by comparing several published human genome scans for positive selection with our findings in non-human primate genomes. We thus provide extensive evidence that the co-occurrence of positive selection in humans and in other primates at the same genetic loci can be measured with only four species, an indication that it may be a widespread phenomenon. The identification of positive selection in humans alongside other primates is a powerful tool to outline those genes that were selected uniquely during recent human evolution.},
affiliation = {DYOGEN Lab, CNRS UMR8541, Ecole Normale Sup{\'e}rieure, Paris, France.},
number = {2},
pages = {e1000840},
volume = {6},
year = {2010},
month = {Jan},
language = {eng},
date-added = {2010-02-11 09:18:24 +0100},
date-modified = {2010-02-11 09:18:24 +0100},
doi = {10.1371/journal.pgen.1000840},
pmid = {20140238},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Enard-2010-PLoS%20Genet_Human%20and%20non-human.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p5367},
rating = {0}
}

@article{Fleming:2005p6894,
author = {James S Fleming},
journal = {Behavior research methods},
title = {TETCORR: a computer program to compute smoothed tetrachoric correlation matrices},
abstract = {Although many programs exist for computing tetrachoric correlations, these programs typically lack one or more of the following features: (1) efficient processing of a large number of variables and computing of a matrix of coefficients; (2) a matrix-smoothing capability; (3) an accurate, reliable computing algorithm; (4) the ability to handle missing data; and (5) nominal cost. TETCORR, which combines an algorithm developed by Brown (1977) with starting values obtained from Divgi (1979a) for more efficient computation, was created to address these and other user concerns.},
affiliation = {Embry-Riddle Aeronautical University, Prescott, Arizona, USA. flemingjs@earthlink.net},
number = {1},
pages = {59--64},
volume = {37},
year = {2005},
month = {Feb},
language = {eng},
keywords = {Algorithms, Reproducibility of Results, Statistics as Topic, Humans, Software, Analysis of Variance, Mathematical Computing},
date-added = {2010-03-06 10:57:31 +0100},
date-modified = {2010-07-29 19:18:35 +0200},
pmid = {16097344},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Fleming-2005-Behavior%20research%20methods_TETCORR%20a%20computer.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p6894},
rating = {0}
}

@article{KChiang:2010p9307,
author = {Charleston W K Chiang and Zofia K Z Gajdos and Joshua M Korn and Finny G Kuruvilla and Johannah L Butler and Rachel Hackett and Candace Guiducci and Thutrang T Nguyen and Rainford Wilks and Terrence Forrester and Christopher A Haiman and Katherine D Henderson and Loic Le Marchand and Brian E Henderson and Mark R Palmert and Colin A McKenzie and Helen N Lyon and Richard S Cooper and Xiaofeng Zhu and Joel N Hirschhorn},
journal = {PLoS Genet},
title = {Rapid assessment of genetic ancestry in populations of unknown origin by genome-wide genotyping of pooled samples},
abstract = {As we move forward from the current generation of genome-wide association (GWA) studies, additional cohorts of different ancestries will be studied to increase power, fine map association signals, and generalize association results to additional populations. Knowledge of genetic ancestry as well as population substructure will become increasingly important for GWA studies in populations of unknown ancestry. Here we propose genotyping pooled DNA samples using genome-wide SNP arrays as a viable option to efficiently and inexpensively estimate admixture proportion and identify ancestry informative markers (AIMs) in populations of unknown origin. We constructed DNA pools from African American, Native Hawaiian, Latina, and Jamaican samples and genotyped them using the Affymetrix 6.0 array. Aided by individual genotype data from the African American cohort, we established quality control filters to remove poorly performing SNPs and estimated allele frequencies for the remaining SNPs in each panel. We then applied a regression-based method to estimate the proportion of admixture in each cohort using the allele frequencies estimated from pooling and populations from the International HapMap Consortium as reference panels, and identified AIMs unique to each population. In this study, we demonstrated that genotyping pooled DNA samples yields estimates of admixture proportion that are both consistent with our knowledge of population history and similar to those obtained by genotyping known AIMs. Furthermore, through validation by individual genotyping, we demonstrated that pooling is quite effective for identifying SNPs with large allele frequency differences (i.e., AIMs) and that these AIMs are able to differentiate two closely related populations (HapMap JPT and CHB).},
affiliation = {Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America.},
number = {3},
pages = {e1000866},
volume = {6},
year = {2010},
month = {Jan},
language = {eng},
date-added = {2010-03-22 13:41:54 +0100},
date-modified = {2010-03-22 13:41:54 +0100},
doi = {10.1371/journal.pgen.1000866},
pmid = {20221249},
local-url = {file://localhost/Users/chl/Dropbox/Papers/K%20Chiang-2010-PLoS%20Genet_Rapid%20assessment%20of.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p9307},
rating = {0}
}

@article{Tost:2009p5804,
author = {Heike Tost and Tajvar Alam and Andreas Meyer-Lindenberg},
journal = {Neurosci Biobehav Rev},
title = {Dopamine and psychosis: Theory, pathomechanisms and intermediate phenotypes},
abstract = {Schizophrenia is a chronic, severe, and disabling brain disorder arising from the adverse interaction of predisposing risk genes and environmental factors. The psychopathology is characterized by a wide array of disturbing cognitive, emotional, and behavioral symptoms that interfere with the individual's capacity to function in society. Contemporary pathophysiological models assume that psychotic symptoms are triggered by a dysregulation of dopaminergic activity in the brain, a theory that is tightly linked to the serendipitous discovery of the first effective antipsychotic agents in the early 1950s. In recent years, the availability of modern neuroimaging techniques has significantly expanded our understanding of the key mediator circuits that bridge the gap between genetic susceptibility and clinical phenotype. This paper discusses the pathophysiological concepts, molecular mechanisms and neuroimaging evidence that link psychosis to disturbances in dopamine neurotransmission.},
affiliation = {Unit for Systems Neuroscience in Psychiatry, National Institute of Mental Health, NIH, DHHS, 9000 Rockville Pike, Bethesda, MD 20892-1365, USA; Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, National Institute of Mental Health, NIH, DHHS, 9000 Rockville Pike, Bethesda, MD 20892-1365, USA.},
pages = {},
year = {2009},
month = {Jun},
language = {ENG},
date-added = {2010-02-17 10:09:56 +0100},
date-modified = {2010-02-17 10:09:56 +0100},
doi = {10.1016/j.neubiorev.2009.06.005},
pii = {S0149-7634(09)00086-4},
pmid = {19559045},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Tost-2009-Neurosci%20Biobehav%20Rev_Dopamine%20and%20psychos.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p5804},
rating = {0}
}

@article{AndriesvanderArk:2010p12920,
author = {L Andries van der Ark},
journal = {Psychometrika},
title = {A note on stochastic ordering of the latent trait using the sum of polytomous item scores},
abstract = {In contrast to dichotomous item response theory (IRT) models, most well-known polytomous IRT models do not imply stochastic ordering of the latent trait by the total test score (SOL). This has been thought to make the ordering of respondents on the latent trait using the total test score questionable and throws doubt on the justifiability of using nonparametric polytomous IRT models for ordinal measure- ment. We show that a broad class of polytomous IRT models has a weaker form of SOL, denoted weak SOL, and argue that weak SOL justifies ordering respondents on the latent trait using the total test score and, therefore, the use of nonparametric polytomous IRT models for ordinal measurement.},
number = {2},
pages = {272--279},
volume = {75},
year = {2010},
date-added = {2010-06-24 18:03:21 +0200},
date-modified = {2010-07-29 20:42:55 +0200},
doi = {10.1007/S11336-010-9147-7},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Andries%20van%20der%20Ark-2010-Psychometrika_A%20note%20on%20stochastic.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p12920},
read = {Yes},
rating = {0}
}

@article{Gibbons:2008p5935,
author = {Robert D Gibbons and David J Weiss and David J Kupfer and Ellen Frank and Andrea Fagiolini and Victoria J Grochocinski and Dulal K Bhaumik and Angela Stover and R Darrell Bock and Jason C Immekus},
journal = {Psychiatr Serv},
title = {Using computerized adaptive testing to reduce the burden of mental health assessment},
abstract = {OBJECTIVE: This study investigated the combination of item response theory and computerized adaptive testing (CAT) for psychiatric measurement as a means of reducing the burden of research and clinical assessments. METHODS: Data were from 800 participants in outpatient treatment for a mood or anxiety disorder; they completed 616 items of the 626-item Mood and Anxiety Spectrum Scales (MASS) at two times. The first administration was used to design and evaluate a CAT version of the MASS by using post hoc simulation. The second confirmed the functioning of CAT in live testing. RESULTS: Tests of competing models based on item response theory supported the scale's bifactor structure, consisting of a primary dimension and four group factors (mood, panic-agoraphobia, obsessive-compulsive, and social phobia). Both simulated and live CAT showed a 95% average reduction (585 items) in items administered (24 and 30 items, respectively) compared with administration of the full MASS. The correlation between scores on the full MASS and the CAT version was .93. For the mood disorder subscale, differences in scores between two groups of depressed patients--one with bipolar disorder and one without--on the full scale and on the CAT showed effect sizes of .63 (p<.003) and 1.19 (p<.001) standard deviation units, respectively, indicating better discriminant validity for CAT. CONCLUSIONS: Instead of using small fixed-length tests, clinicians can create item banks with a large item pool, and a small set of the items most relevant for a given individual can be administered with no loss of information, yielding a dramatic reduction in administration time and patient and clinician burden.},
affiliation = {Center for Health Statistics, University of Illinois at Chicago, Psychiatric Institute 457, M/C 912, Chicago, IL 60680-6998, USA. rdgib@uic.edu},
number = {4},
pages = {361--8},
volume = {59},
year = {2008},
month = {Apr},
language = {eng},
keywords = {Diagnosis: Computer-Assisted, Adolescent, Mood Disorders, Aged, Bipolar Disorder, Male, Agoraphobia, Anxiety Disorders, Reproducibility of Results, Mental Disorders, Panic Disorder, Obsessive-Compulsive Disorder, Time Factors, Middle Aged, Adult, Questionnaires, Humans, Female, Phobic Disorders},
date-added = {2010-02-18 23:14:58 +0100},
date-modified = {2010-07-29 19:45:23 +0200},
doi = {10.1176/appi.ps.59.4.361},
pii = {59/4/361},
pmid = {18378832},
URL = {http://ps.psychiatryonline.org/cgi/content/full/59/4/361},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Gibbons-2008-Psychiatr%20Serv_Using%20computerized%20a.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p5935},
rating = {0}
}

@article{Hardouin:2007b,
author = {J-B Hardouin},
journal = {Communications in Statistics - Simulation and Computation},
title = {The SAS Macro-Program %AnaQol to Estimate the Parameters of Item Responses Theory Models},
number = {2},
pages = {437--453},
volume = {36},
year = {2007},
date-added = {2010-01-10 11:33:18 +0100},
date-modified = {2010-01-10 11:33:25 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Hardouin-2007-Communications%20in%20Statistics%20-%20Simulation%20and%20Computation_The%20SAS%20Macro-Progra.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p2162},
rating = {0}
}

@article{Xu:2005p4746,
author = {H Xu},
title = {Using the Partitioning Principle to Control Generalized Familywise Error Rate},
abstract = {In multiple testing, strong control of the familywise error rate (FWER) may be unnecessarily stringent in some situations such as bioinformatic studies. An alterna- tive is to control the false discovery rate (FDR), the expected proportion of true null hypotheses among all rejected null hypotheses. However, in bioinformatic studies, the loss or cost of false discoveries often corresponds to the number rather than the propor- tion of false discoveries. Controlling the generalized familywise error rate (gFWER) controls the probability of incorrectly rejecting strictly more than m hypotheses. In this dissertation, we propose the generalized partitioning principle for constructing multiple tests that control gFWER. A set of sufficient conditions to shortcut general- ized partitioning tests as step-down tests is provided. We show that, by being able to use information on the joint distribution of test statistics, step-down tests we propose can be more powerful than stepdown tests that ignore such information.},
year = {2005},
date-added = {2010-02-01 11:41:18 +0100},
date-modified = {2010-02-01 11:42:42 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Xu-2005-_Using%20the%20Partitioni.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p4746},
rating = {0}
}

@article{Ware:1998p1845,
author = {J E Ware and B Gandek},
journal = {Journal of Clinical Epidemiology},
title = {Methods for testing data quality, scaling assumptions, and reliability: the IQOLA Project approach. International Quality of Life Assessment},
abstract = {Following the translation development stage, the second research stage of the IQOLA Project tests the assumptions underlying item scoring and scale construction. This article provides detailed information on the research methods used by the IQOLA Project to evaluate data quality, scaling and scoring assumptions, and the reliability of the SF-36 scales. Tests include evaluation of item and scale-level descriptive statistics; examination of the equality of item-scale correlations, item internal consistency and item discriminant validity; and estimation of scale score reliability using internal consistency and test-retest methods. Results from these tests are used to determine if standard algorithms for the construction and scoring of the eight SF-36 scales can be used in each country and to provide information that can be used in translation improvement.},
affiliation = {Health Assessment Lab at the Health Institute, New England Medical Center, Boston, Massachusetts 02111, USA.},
number = {11},
pages = {945--52},
volume = {51},
year = {1998},
month = {Nov},
language = {eng},
keywords = {Health Status Indicators, Discriminant Analysis, Psychometrics, Quality of Life, Translations, Humans, Activities of Daily Living},
date-added = {2010-01-10 10:44:29 +0100},
date-modified = {2010-01-10 10:44:29 +0100},
pii = {S0895435698000857},
pmid = {9817111},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Ware-1998-Journal%20of%20Clinical%20Epidemiology_Methods%20for%20testing.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p1845},
rating = {0}
}

@article{Dixon:2003p7097,
author = {Peter Dixon},
journal = {Can J Exp Psychol},
title = {The p-value fallacy and how to avoid it},
abstract = {Null hypothesis significance tests are commonly used to provide a link between empirical evidence and theoretical interpretation. However, this strategy is prone to the "p-value fallacy" in which effects and interactions are classified as either "noise" or "real" based on whether the associated p value is greater or less than .05. This dichotomous classification can lead to dramatic misconstruals of the evidence provided by an experiment. For example, it is quite possible to have similar patterns of means that lead to entirely different patterns of significance, and one can easily find the same patterns of significance that are associated with completely different patterns of means. Describing data in terms of an inventory of significant and nonsignificant effects can thus completely misrepresent the results. An alternative analytical technique is to identify competing interpretations of the data and then use likelihood ratios to assess which interpretation provides the better account. Several different methods of calculating the likelihood ratios are illustrated. It is argued that this approach satisfies a principle of "graded evidence," according to which similar data should provide similar evidence.},
affiliation = {Department of Psychology, University of Alberta, Edmonton. cjep@ualberta.ca},
number = {3},
pages = {189--202},
volume = {57},
year = {2003},
month = {Sep},
language = {eng},
keywords = {Models: Psychological, Humans, Research Design},
date-added = {2010-03-06 20:30:13 +0100},
date-modified = {2010-03-06 20:30:13 +0100},
pmid = {14596477},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p7097},
rating = {0}
}

@article{McCrae:2009p12034,
author = {RR McCrae},
journal = {Online Readings in Psychology and Culture},
title = {Cross-Cultural Research on the Five-Factor Model of Personality},
abstract = {The Five-Factor Model (FFM) is a comprehensive taxonomy of personality traits, which are tendencies to show consistent patterns of thoughts, feelings, and actions. Although it was originally identified in the United States, the model appears to describe personality structure well in a wide variety of cultures, suggesting that personality trait structure is universal. Age changes--decreases in Neuroticism, Extraversion, and Openness and increases in Agreeableness and Conscientiousness from adolescence to adulthood--also appear to be universal, as are gender differences. Current studies comparing the mean levels of personality traits across cultures show systematic patterns, but their interpretation is uncertain. The FFM is currently in use by psychologists around the world in a variety of applications.},
year = {2009},
date-added = {2010-05-24 10:29:34 +0200},
date-modified = {2010-05-24 10:30:11 +0200},
local-url = {file://localhost/Users/chl/Dropbox/Papers/McCrae-2009-Online%20Readings%20in%20Psychology%20and%20Culture_Cross-Cultural%20Resea.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p12034},
rating = {0}
}

@article{Groessl:2006p4552,
author = {E J Groessl and K R Weingart and R M Kaplan and S B Ho},
title = {Health-Related Quality of Life in HCV-Infected Patients},
abstract = {In March 2007, a systematic review was conducted of published research on the topic of health-related quality of life (HRQOL) in patients with hepatitis C virus (HCV) infection. Recent studies indicate that significant decre- ments in HRQOL exist for patients with HCV under many circumstances and arise from multiple sources. Future research is needed on finding interventions that address all sources of reduced HRQOL in patients with HCV, whether or not they are on treatment. It is also important to continue work on identifying the direct mechanisms behind lower HRQOL in patients with HCV.},
year = {2006},
date-added = {2010-01-29 22:30:07 +0100},
date-modified = {2010-01-29 22:31:37 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Groessl-2006-_Health-Related%20Quali.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p4552},
read = {Yes},
rating = {0}
}

@article{Huang:2007p3836,
author = {B E Huang and C I Amos and D Y Lin},
journal = {Genet Epidemiol},
title = {Detecting haplotype effects in genomewide association studies},
abstract = {The analysis of genomewide association studies requires methods that are both computationally feasible and statistically powerful. Given the large-scale collection of single nucleotide polymorphisms (SNPs), it is desirable to explore the information contained in their interrelationships. In particular, utilizing haplotypes rather than individual SNPs and accounting for correlations of polymorphisms in adjustment for multiple testing can lead to increased power. We present a statistically powerful and numerically efficient method based on sliding windows of adjacent SNPs to detect haplotype-disease association in genomewide studies. This method consists of an efficient algorithm to calculate a proper likelihood-ratio statistic for any given window of SNPs, along with an accurate and efficient Monte Carlo procedure to adjust for multiple testing. Simulation studies using the HapMap data showed that the proposed method performs well in realistic situations. We applied the new method to a case-control study on rheumatoid arthritis and identified several loci worthy of further investigations.},
affiliation = {Department of Biostatistics, University of North Carolina, North Carolina 27599-7420, USA.},
number = {8},
pages = {803--12},
volume = {31},
year = {2007},
month = {Dec},
language = {eng},
keywords = {Case-Control Studies, Algorithms, Genome: Human, Genetic Diseases: Inborn, Adult, Chromosomes: Human: Pair 18, Adolescent, Data Interpretation: Statistical, Middle Aged, Humans, Arthritis: Rheumatoid, Male, Polymorphism: Single Nucleotide, Likelihood Functions, Haplotypes, Female, Computer Simulation},
date-added = {2010-01-16 21:02:15 +0100},
date-modified = {2010-01-16 21:02:15 +0100},
doi = {10.1002/gepi.20242},
pmid = {17549762},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p3836},
rating = {0}
}

@article{Verstralen:1998ab,
author = {H H F M Verstralen},
title = {A Logistic Latent Class Model for Multiple Choice Items},
abstract = {A logistic latent class model for the analysis of options of a class of multiple choice items is presented. For each item a set of latent classes with a chain structure is assumed. The probability of latent class membership is modeled by a logistic function. The conditional probability of the observed response, the selection of an option, given the latent class membership is assumed to be constant. The model can be viewed as a generalization of Nedelsky's (1954) method to determine a pass/fail score. Apart from giving a more detailed model on the process of solving a multiple choice item an increase in the precision of latent variable estimates in comparison with binary scoring is achieved. The model is shown to possess some favorable psychometric properties.},
year = {1998},
month = {Sep},
date-added = {2010-01-03 19:39:03 +0100},
date-modified = {2010-01-03 19:39:03 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Verstralen-1998-_A%20Logistic%20Latent%20Cl.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p1210},
rating = {0}
}

@article{Caruso:2001,
author = {J C Caruso and S Edwards},
journal = {Personality and Individual Differences},
title = {Reliability Generalization of the Junior Eysenck Personality Questionnaire},
abstract = {A reliability generalization was conducted on the Psychoticism (P), Extraversion (E), Neuroticism (N) and Lie (L) scales of the Junior Eysenck Personality Questionnaire (J-EPQ). Twenty-three studies provided data on 44 samples of children who had been administered the J-EPQ. Score reliability was found to vary significantly both between and within scales. N and L provided the most reliable scores (with median reliabilities of 0.80 and 0.79 respectively) followed by E (median RELIABILITY=0.73) and P (median RELIABILITY=0.68). Scale length was the best predictor of score reliability, but sample gender makeup, language of administration, and the amount of variation in the ages of children in each sample were also significant predictors of reliability for various J-EPQ scales. The results highlight the importance of considering reliability to be a property of scores for a particular group, as opposed to a property of a test generally.},
number = {2},
pages = {173--184},
volume = {31},
year = {2001},
date-added = {2010-01-10 11:33:21 +0100},
date-modified = {2010-01-10 11:33:25 +0100},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p1978},
rating = {0}
}

@misc{Albert:2006,
author = {Paul S Albert and L E Dodd},
journal = {Miscellaneous},
title = {On Estimating Diagnostic Accuracy From Studies With Multiple Raters and Partial Gold Standard Evaluation},
year = {2006},
month = {Mar},
date-added = {2010-01-10 11:33:09 +0100},
date-modified = {2010-07-29 20:18:34 +0200},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Albert-2006-Miscellaneous_On%20Estimating%20Diagno.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p1887},
rating = {0}
}

@article{Warton:2010p12495,
author = {David I Warton},
journal = {Biometrics},
title = {Regularized Sandwich Estimators for Analysis of High-Dimensional Data Using Generalized Estimating Equations},
abstract = {Summary. A modification of generalized estimating equations (GEEs) methodology is proposed for hypothesis testing of high-dimensional data, with particular interest in multivariate abundance data in ecology, an important application of interest in thousands of environmental science studies. Such data are typically counts characterized by high dimensionality (in the sense that cluster size exceeds number of clusters, n>K) and over-dispersion relative to the Poisson distribution. Usual GEE methods cannot be applied in this setting primarily because sandwich estimators become numerically unstable as n increases. We propose instead using a regularized sandwich estimator that assumes a common correlation matrix R, and shrinks the sample estimate of R toward the working correlation matrix to improve its numerical stability. It is shown via theory and simulation that this substantially improves the power of Wald statistics when cluster size is not small. We apply the proposed approach to study the effects of nutrient addition on nematode communities, and in doing so discuss important issues in implementation, such as using statistics that have good properties when parameter estimates approach the boundary (), and using resampling to enable valid inference that is robust to high dimensionality and to possible model misspecification.},
affiliation = {School of Mathematics and Statistics and Evolution and Ecology Research Centre, The University of New South Wales, NSW 2052, Australia.},
pages = {},
year = {2010},
month = {May},
language = {ENG},
date-added = {2010-06-15 17:39:28 +0200},
date-modified = {2010-06-15 17:39:28 +0200},
doi = {10.1111/j.1541-0420.2010.01438.x},
pii = {BIOM1438},
pmid = {20528857},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Warton-2010-Biometrics_Regularized%20Sandwich.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p12495},
rating = {0}
}

@article{Mechelli:2009p8826,
author = {Andrea Mechelli and Essi Viding and William Pettersson-Yeo and Stefania Tognin and Philip K McGuire},
journal = {Hum Brain Mapp},
title = {Genetic variation in neuregulin1 is associated with differences in prefrontal engagement in children},
abstract = {The majority of psychopathology is rooted early in life and first emerges during childhood and adolescence. However, little is known about how risk genes affect brain function to increase biological vulnerability to psychopathology in childhood, because most imaging genetic studies published so far have been conducted on adult participants. We examined the impact of neuregulin1 (NRG1), a probable susceptibility gene for schizophrenia and bipolar disorder, on brain function in a sample of 102 ten- to twelve-year-old children. Each participant performed a Go/Nogo task, whereas brain responses were measured using functional magnetic resonance imaging. Statistical parametric mapping was used to estimate the impact of genetic variation in NRG1 on brain activation. Response accuracy and reaction times did not differ as a function of NRG1 genotype. However, individuals with the high-risk variant expressed greater brain activation for both Go and Nogo stimuli in the right posterior orbital gyrus, where NRG1 genotype accounted for 11% of interindividual variance. There were no regions showing a significant interaction between NRG1 genotype and stimulus type even at trend level, suggesting that the impact of NRG1 on brain activation was not specific to either response inhibition or motor execution. These results suggest that that genetic variation in NRG1 is associated with different levels of prefrontal engagement in children as young as 10-12 years of age. Our investigation provides support to the idea that genetic factors may affect brain function to moderate vulnerability to psychopathology from childhood.},
affiliation = {Department of Psychology, Institute of Psychiatry, King's College London, London, United Kingdom. a.mechelli@iop.kcl.ac.uk},
number = {12},
pages = {3934--43},
volume = {30},
year = {2009},
month = {Dec},
language = {eng},
keywords = {Brain, Image Interpretation: Computer-Assisted, Male, Magnetic Resonance Imaging, Child, Reaction Time, Neuregulin-1, Genetic Variation, Brain Mapping, Genetic Predisposition to Disease, Genotype, Humans, Mental Disorders},
date-added = {2010-03-22 12:33:19 +0100},
date-modified = {2010-03-22 12:33:19 +0100},
doi = {10.1002/hbm.20818},
pmid = {19449332},
URL = {http://www3.interscience.wiley.com/journal/122385643/abstract},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Mechelli-2009-Hum%20Brain%20Mapp_Genetic%20variation%20in.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p8826},
rating = {0}
}

@article{Cox:2007p4029,
author = {D D Cox and J S Lee},
title = {Pointwise Testing with Functional Data Using the Westfall-Young Randomization Method},
abstract = {We consider hypothesis testing with smooth functional data by performing pointwise tests and applying a multiple comparisons proce- dure. Methods based on general inequalities (e.g., Bonferroni's method) do not perform well because of the high correlation between observa- tions at nearby points. We consider the multiple comparison procedure proposed by Westfall and Young (1993) and show that it approximates a multiple comparison correction for a continuum of comparisons as the grid for pointwise comparisons becomes finer. Simulations verify that this result applies in practical settings.},
year = {2007},
date-added = {2010-01-19 08:23:46 +0100},
date-modified = {2010-01-19 08:24:22 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Cox-2007-_Pointwise%20Testing%20wi.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p4029},
rating = {0}
}

@article{Bernau:2009p11609,
author = {C Bernau and A-L Boulesteix},
title = {Variable Selection and Parameter Tuning in High-Dimensional Prediction},
abstract = {In the context of classification using high-dimensional data such as microarray gene expression data, it is often useful to perform preliminary variable selection. For example, the k-nearest-neighbors classification procedure yields a much higher accuracy when applied on variables with high discriminatory power. Typical (univariate) variable selection methods for binary classification are, e.g., the two-sample t-statistic or the Mann-Whitney test.
In small sample settings, the classification error rate is often estimated using cross-validation (CV) or related approaches. The variable selection procedure has then to be applied for each considered training set anew, i.e. for each CV iteration successively. Performing variable selection based on the whole sample before the CV procedure would yield a downwardly biased error rate estimate. CV may also be used to tune parameters involved in a classification method. For instance, the penalty parameter in penalized regression or the cost in support vector machines are most often selected using CV. This type of CV is usually denoted as ''internal CV'' in contrast to the ''external CV'' performed to estimate the error rate, while the term ''nested CV'' refers to the whole procedure embedding two CV loops.
While variable selection and parameter tuning via internal CV have been widely investigated in the context of high-dimensional classification, it is still unclear how they should be combined if a classification method involves both variable selec- tion and parameter tuning. For example, the k-nearest-neighbors method usually requires variable selection and involves a tuning parameter: the number k of neigh- bors. It is well-known that variable selection should be repeated for each external CV iteration. But should we also repeat variable selection for each internal CV iteration or rather perform tuning based on fixed subset of variables? While the first variant seems more natural, it implies a huge computational expense and its benefit in terms of error rate remains unknown.},
number = {76},
year = {2009},
date-added = {2010-05-11 17:23:18 +0200},
date-modified = {2010-05-11 17:24:13 +0200},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Bernau-2009-_Variable%20Selection%20a.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p11609},
rating = {4}
}

@article{Hickie:2002p5420,
author = {Ian B Hickie and Gavin Andrews and Tracey A Davenport},
journal = {Med J Aust},
title = {Measuring outcomes in patients with depression or anxiety: an essential part of clinical practice},
abstract = {A wide range of instruments is available for ongoing assessment of clinical status and outcome in patients with depressive or anxiety disorders. However, few doctors use these instruments in managing their patients. As depression and anxiety are relapsing or chronic conditions and are often comorbid with other medical conditions, standard outcome measures should be incorporated into the management plans for all such patients.},
affiliation = {School of Psychiatry, University of New South Wales at St George Hospital, Sydney, NSW. ian.hickie@beyondblue.org.au},
number = {4},
pages = {205--7},
volume = {177},
year = {2002},
month = {Aug},
language = {eng},
keywords = {Psychological Tests, Humans, Anxiety Disorders, Continuity of Patient Care, Comorbidity, Physician's Role, Chronic Disease, Depressive Disorder, Outcome Assessment (Health Care)},
date-added = {2010-02-11 10:37:06 +0100},
date-modified = {2010-02-11 10:37:06 +0100},
pii = {hic10058_fm},
pmid = {12175326},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Hickie-2002-Med%20J%20Aust_Measuring%20outcomes%20i.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p5420},
rating = {0}
}

@misc{Chun2007,
author = {H Chun and S Kele\c s},
journal = {Miscellaneous},
title = {Sparse partial least squares regression for simultaneous dimension reduction and variable selection},
year = {2007},
date-added = {2010-01-12 14:26:40 +0100},
date-modified = {2010-01-12 14:26:52 +0100},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p2548},
rating = {0}
}

@article{Patil:2001p4526,
author = {R Patil and S J Cotler and G Banaad-Omiotek and R A McNutt and M D Brown and S Cotler and D M Jensen},
journal = {BMC Gastroenterol},
title = {Physicians' preference values for hepatitis C health states and antiviral therapy: a survey},
abstract = {BACKGROUND: Physicians' perspectives regarding hepatitis C shape their approach to patient management. We used utility analysis to evaluate physicians' perceptions of hepatitis C-related health states (HS) and their threshold to recommend treatment. METHODS: A written questionnaire was administered to practicing physicians. They were asked to rate hepatitis C health states on a visual analog scale ranging from 0% (death) to 100% (health without hepatitis C). Physicians then judged quality of life associated with the side effects of antiviral therapy for hepatitis C and indicated the sustained virological response rate that they would require to recommend treatment. RESULTS: One hundred and thirteen physicians from five states were included. Median utility ratings for hepatitis C health states declined significantly with increasing severity of symptoms: HS1-No Symptoms, No Cirrhosis (88%; 12% reduction from good health), HS2-Mild Symptoms, No Cirrhosis (66%), HS3-Moderate Symptoms, No Cirrhosis (49%), HS4-Mild Symptoms, Cirrhosis (40%), HS5-Severe Symptoms, Cirrhosis (18%) [p < 0.001]. The median rating for life with side effects of antiviral therapy was 47%, suggesting a 53% reduction from good health. That was similar to the utility value for HS3-Moderate Symptoms, No Cirrhosis. The median threshold value for recommending treatment was a sustained response rate of 60%. CONCLUSIONS: 1) Physicians' utility ratings for hepatitis C health states were inversely related to the severity of disease manifestations described. 2) Physicians viewed side effects of therapy unfavorably and indicated that on average, they would require a 60% sustained response rate before recommending treatment, which far exceeds the efficacy of current antiviral therapy for hepatitis C in the majority of patients.},
affiliation = {Section of Hepatology, RUSH-Presbyterian-St Luke's Medical Center, 1725 W Harrison St, Suite 306, Chicago, IL 60612, USA. rpatil@ameritech.net},
pages = {6},
volume = {1},
year = {2001},
month = {Jan},
language = {eng},
keywords = {Data Collection, Liver Cirrhosis, Health Knowledge: Attitudes: Practice, Humans, Antiviral Agents, United States, Physicians, Hepatitis C: Chronic, Quality of Life, Questionnaires},
date-added = {2010-01-29 22:14:49 +0100},
date-modified = {2010-01-29 22:14:49 +0100},
pmid = {11513756},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p4526},
rating = {0}
}

@article{Garratt:2010p12841,
author = {A M Garratt and J Helgeland and P Gulbrandsen},
journal = {Journal of Clinical Epidemiology},
title = {Five-point scales outperform 10-point scales in a randomized comparison of item scaling for the Patient Experiences Questionnaire},
abstract = {Objective: To assess the data quality of two approaches to scaling items within the Patient Experiences Questionnaire (PEQ); a five- point scale with descriptors for all scale points and a 10-point scale with descriptors only at the end points.
Study Design and Setting: The two versions were pretested through cognitive interviews with 14 patients. The PEQ was then mailed to 1,000 patients after inpatient treatment at a large university hospital in Norway, randomized to receive the 5- or 10-point scale versions. Response rates, missing data, item means, floor, and ceiling effects were assessed. Regression analysis was used to examine the impact of response scale on missing data, floor, and ceiling effects after controlling for age, education level, and health status.
Results: The five-point scale produced data with unimodal and fairly symmetric distributions in contrast to the highly skewed J- and U-shaped distributions for the 10-point scale. The five-point scale data had significantly lower item means, floor, and ceiling effects. Regression analysis showed that the type of scale explained a significant component of the variation in both floor and ceiling effects.
Conclusion: The five-point scale performed better than the 10-point scale and is more suitable for assessing patient experiences. The revised PEQ will be used in Norwegian national surveys.},
year = {2010},
date-added = {2010-06-21 20:06:25 +0200},
date-modified = {2010-06-21 20:07:20 +0200},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Garratt-2010-Journal%20of%20Clinical%20Epidemiology_Five-point%20scales%20ou.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p12841},
rating = {0}
}

@article{Alaerts:2009p3731,
author = {Maaike Alaerts and Jurgen Del-Favero},
journal = {Hum Mutat},
title = {Searching genetic risk factors for schizophrenia and bipolar disorder: learn from the past and back to the future},
abstract = {For more than 20 years already, researchers from all over the world have tried to get insight into the genetic basis of psychiatric disorders such as schizophrenia (SZ) and bipolar (BP) disorder. Linkage and candidate gene association study results have led to a range of hypotheses about the pathogenesis of the disorders, but overall genetic findings have been inconsistent and not a single functional risk causing variant has yet been identified. Even genomewide association (GWA) studies in large samples, the most extensive and systematic interrogation of the genome thus far, seemingly have not brought the expected answers. A reasonable interpretation is that multiple rare variants, inherently linked with locus and allelic heterogeneity, confer a substantial proportion of susceptibility to the disorders. Also, structural variation might be an important factor and promising results are arising from copy-number variation (CNV) analyses. In this review we shortly touch on "old" results from linkage and association studies and critically review the design and "new" results of GWA and CNV studies. We discuss what can be learned from the past and how this knowledge can be used in future study designs.},
affiliation = {Applied Molecular Genomics Group, Vlaams Instituut voor Biotechnologie [Flanders Institute for Biotechnology], Department of Molecular Genetics, University of Antwerp, Antwerp B-2610, Belgium.},
number = {8},
pages = {1139--52},
volume = {30},
year = {2009},
month = {Aug},
language = {eng},
keywords = {Bipolar Disorder, Gene Dosage, Genome-Wide Association Study, Genetic Predisposition to Disease, Humans, Risk Factors, Schizophrenia, Linkage (Genetics)},
date-added = {2010-01-16 20:57:40 +0100},
date-modified = {2010-01-16 20:57:40 +0100},
doi = {10.1002/humu.21042},
pmid = {19626716},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p3731},
rating = {0}
}

@article{Gao:2005p12803,
author = {L Gao and C Wang},
journal = {NCME},
title = {Using Five Procedures to Detect DIF with Passage-Based Testlets},
abstract = {The objective of this study was to assess differential item functioning (DIF) for passage-based
reading testlets across two gender groups using five procedures and then to compare the results across the procedures. The five procedures were: (1) polytomous logistic regression (PLR; Zumbo, 1999), (2) graded response model (GRM; Samejima, 1969, 1997), (3) Mantel-Haenszel (MH; Zwick, Donoghue, {\&} Grima, 1993), (4) polytomous SIBTEST (Poly-SIBTEST; Chang, Mazzeo, {\&} Roussos, 1996), and (5) testlet response theory model (TRTM; Wang, Bradlow and Wainer, 2002). Consistent results were produced between the PLR, MH, and Poly-SIBTEST procedures but not the other two. A simulation study was called for to evaluate the accuracy of each procedure in the passage-based testlet situation.},
year = {2005},
date-added = {2010-06-18 22:48:07 +0200},
date-modified = {2010-06-18 22:48:37 +0200},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Gao-2005-NCME_Using%20Five%20Procedure.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p12803},
rating = {3}
}

@article{Limbers:2009p7981,
author = {Christine A Limbers and Daniel A Newman and James W Varni},
journal = {Annals of Epidemiology},
title = {Factorial invariance of child self-report across race/ethnicity groups: a multigroup confirmatory factor analysis approach utilizing the PedsQL 4.0 Generic Core Scales},
abstract = {PURPOSE: In order to compare health-related quality of life (HRQOL) research findings across race/ethnicity subpopulations, it is important to demonstrate factorial invariance, i.e., that the items have equivalent meaning across the race/ethnicity groups studied. This study examined the factorial invariance of child self-reported HRQOL across race/ethnicity groups for ages 5-18 years utilizing the 23-item PedsQL 4.0 Generic Core Scales. METHODS: Multigroup confirmatory factor analysis (CFA) was performed, specifying a five-factor model across four race/ethnicity groups (White Non-Hispanic, Hispanic, Asian/Pacific Islander, Black Non-Hispanic). Multigroup structural equation models were proposed in order to compare the factor structure across the four race/ethnicity subpopulations. The analyses were based on 5,490 children recruited from clinic, school, and community populations. RESULTS: Strict factorial invariance across the four race/ethnicity groups was demonstrated based on stability of the Comparative Fit Index (CFI) between the models, and several additional indices of practical fit including the Root Mean Squared Error of Approximation (RMSEA), the Non-Normed Fit Index (NNFI), and the Parsimony Normed Fit Index (PNFI). CONCLUSIONS: The findings support an equivalent five-factor structure across the four race/ethnicity subpopulations studied. Based on these data, it can be concluded that children across the four race/ethnicity groups studied interpreted items in a similar manner regardless of their race/ethnicity.},
affiliation = {Department of Psychology, College of Liberal Arts, Texas A{\&}M University, College Station, TX 77843-3137, USA.},
number = {8},
pages = {575--81},
volume = {19},
year = {2009},
month = {Aug},
language = {eng},
keywords = {Quality of Life, Continental Population Groups, Ethnic Groups, Factor Analysis: Statistical, Humans, Male, Data Collection, Child, Female, Health Status, Adolescent, Child: Preschool},
date-added = {2010-03-20 19:33:43 +0100},
date-modified = {2010-03-20 19:33:43 +0100},
doi = {10.1016/j.annepidem.2009.04.004},
pii = {S1047-2797(09)00126-4},
pmid = {19576538},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Limbers-2009-Annals%20of%20Epidemiology_Factorial%20invariance.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p7981},
rating = {0}
}

@article{Becker:2005p3102,
author = {Tim Becker and Michael Knapp},
journal = {Hum Hered},
title = {Impact of missing genotype data on Monte-Carlo simulation based haplotype analysis},
abstract = {In the context of haplotype association analysis of unphased genotype data, methods based on Monte-Carlo simulations are often used to compensate for missing or inappropriate asymptotic theory. Moreover, such methods are an indispensable means to deal with multiple testing problems. We want to call attention to a potential trap in this usually useful approach: The simulation approach may lead to strongly inflated type I errors in the presence of different missing rates between cases and controls, depending on the chosen test statistic. Here, we consider four different testing strategies for haplotype analysis of case-control data. We recommend to interpret results for data sets with non-comparable distributions of missing genotypes with special caution, in case the test statistic is based on inferred haplotypes per individual. Moreover, our results are important for the conduction and interpretation of genome-wide association studies.},
affiliation = {Institute for Medical Biometry, Informatics and Epidemiology University of Bonn, Bonn, Germany. becker@imbie.meb.uni-bonn.de},
number = {4},
pages = {185--9},
volume = {59},
year = {2005},
month = {Jan},
language = {eng},
keywords = {Haplotypes, Humans, Case-Control Studies, Computer Simulation, Likelihood Functions, Monte Carlo Method, Genotype},
date-added = {2010-01-14 20:19:00 +0100},
date-modified = {2010-01-14 20:19:01 +0100},
doi = {10.1159/000086696},
pii = {HHE2005059004185},
pmid = {16015028},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p3102},
rating = {0}
}

@article{Seda:2008p11372,
author = {Ondrej Seda and Johanne Tremblay and Daniel Gaudet and Pierre-Luc Brunelle and Alexandru Gurau and Ettore Merlo and Louise Pilote and Sergei N Orlov and Francis Boulva and Milan Petrovich and Theodore A Kotchen and Allen W Cowley and Pavel Hamet},
journal = {Hypertension},
title = {Systematic, genome-wide, sex-specific linkage of cardiovascular traits in French Canadians},
abstract = {The sexual dimorphism of cardiovascular traits, as well as susceptibility to a variety of related diseases, has long been recognized, yet their sex-specific genomic determinants are largely unknown. We systematically assessed the sex-specific heritability and linkage of 539 hemodynamic, metabolic, anthropometric, and humoral traits in 120 French-Canadian families from the Saguenay-Lac-St-Jean region of Quebec, Canada. We performed multipoint linkage analysis using microsatellite markers followed by peak-wide linkage scan based on Affymetrix Human Mapping 50K Array Xba240 single nucleotide polymorphism genotypes in 3 settings, including the entire sample and then separately in men and women. Nearly one half of the traits were age and sex independent, one quarter were both age and sex dependent, and one eighth were exclusively age or sex dependent. Sex-specific phenotypes are most frequent in heart rate and blood pressure categories, whereas sex- and age-independent determinants are predominant among humoral and biochemical parameters. Twenty sex-specific loci passing multiple testing criteria were corroborated by 2-point single nucleotide polymorphism linkage. Several resting systolic blood pressure measurements showed significant genotype-by-sex interaction, eg, male-specific locus at chromosome 12 (male-female logarithm of odds difference: 4.16; interaction P=0.0002), which was undetectable in the entire population, even after adjustment for sex. Detailed interrogation of this locus revealed a 220-kb block overlapping parts of TAO-kinase 3 and SUDS3 genes. In summary, a large number of complex cardiovascular traits display significant sexual dimorphism, for which we have demonstrated genomic determinants at the haplotype level. Many of these would have been missed in a traditional, sex-adjusted setting.},
affiliation = {Centre de Recherche, Centre Hospitalier de l'Universit{\'e} de Montr{\'e}al-Techn{\^o}pole Angus, Montreal, Quebec, Canada.},
number = {4},
pages = {1156--62},
volume = {51},
year = {2008},
month = {Apr},
language = {eng},
keywords = {Quebec, Humans, Linkage Disequilibrium, Microsatellite Repeats, Sex Characteristics, Sex Distribution, Female, Lod Score, Polymorphism: Single Nucleotide, Chromosomes: Human: Pair 12, Genetic Predisposition to Disease, Cardiovascular Diseases, Male, Haplotypes, Phenotype, Genomics},
date-added = {2010-04-26 23:09:38 +0200},
date-modified = {2010-04-26 23:09:38 +0200},
doi = {10.1161/HYPERTENSIONAHA.107.105247},
pii = {HYPERTENSIONAHA.107.105247},
pmid = {18259002},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Seda-2008-Hypertension_Systematic%20genome-w.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p11372},
rating = {0}
}

@article{Lui:2008p9435,
author = {Kung-Jong Lui and Kuang-Chao Chang},
journal = {Stat Med},
title = {Sample size determination for assessing equivalence based on proportion ratio under a randomized trial with non-compliance and missing outcomes},
abstract = {When a generic drug is developed, it is important to assess the equivalence of therapeutic efficacy between the new and the standard drugs. Although the number of publications on testing equivalence and its relevant sample size determination is numerous, the discussion on sample size determination for a desired power of detecting equivalence under a randomized clinical trial (RCT) with non-compliance and missing outcomes is limited. In this paper, we derive under the compound exclusion restriction model the maximum likelihood estimator (MLE) for the ratio of probabilities of response among compliers between two treatments in a RCT with both non-compliance and missing outcomes. Using the MLE with the logarithmic transformation, we develop an asymptotic test procedure for assessing equivalence and find that this test procedure can perform well with respect to type I error based on Monte Carlo simulation. We further develop a sample size calculation formula for a desired power of detecting equivalence at a nominal alpha-level. To evaluate the accuracy of the sample size calculation formula, we apply Monte Carlo simulation again to calculate the simulated power of the proposed test procedure corresponding to the resulting sample size for a desired power of 80 per cent at 0.05 level in a variety of situations. We also include a discussion on determining the optimal ratio of sample size allocation subject to a desired power to minimize a linear cost function and provide a sensitivity analysis of the sample size formula developed here under an alterative model with missing at random.},
affiliation = {Department of Mathematics and Statistics, San Diego State University, San Diego, CA 92182-7720, U.S.A. kjl@rohan.sdsu.edu},
number = {1},
pages = {47--67},
volume = {27},
year = {2008},
month = {Jan},
language = {eng},
keywords = {Middle Aged, Adult, Likelihood Functions, Therapeutic Equivalency, Randomized Controlled Trials as Topic, Drug Evaluation, Patient Compliance, Coronary Disease, Humans, Drugs: Generic, Monte Carlo Method, Sample Size, Male, Data Interpretation: Statistical, Models: Statistical},
date-added = {2010-03-23 19:02:20 +0100},
date-modified = {2010-03-23 19:02:20 +0100},
doi = {10.1002/sim.3030},
pmid = {17708514},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p9435},
rating = {0}
}

@article{Franke:2006p2977,
author = {Lude Franke and Harm van Bakel and Like Fokkens and Edwin D de Jong and Michael Egmont-Petersen and Cisca Wijmenga},
journal = {American Journal of Human Genetics},
title = {Reconstruction of a functional human gene network, with an application for prioritizing positional candidate genes},
abstract = {Most common genetic disorders have a complex inheritance and may result from variants in many genes, each contributing only weak effects to the disease. Pinpointing these disease genes within the myriad of susceptibility loci identified in linkage studies is difficult because these loci may contain hundreds of genes. However, in any disorder, most of the disease genes will be involved in only a few different molecular pathways. If we know something about the relationships between the genes, we can assess whether some genes (which may reside in different loci) functionally interact with each other, indicating a joint basis for the disease etiology. There are various repositories of information on pathway relationships. To consolidate this information, we developed a functional human gene network that integrates information on genes and the functional relationships between genes, based on data from the Kyoto Encyclopedia of Genes and Genomes, the Biomolecular Interaction Network Database, Reactome, the Human Protein Reference Database, the Gene Ontology database, predicted protein-protein interactions, human yeast two-hybrid interactions, and microarray co-expressions. We applied this network to interrelate positional candidate genes from different disease loci and then tested 96 heritable disorders for which the Online Mendelian Inheritance in Man database reported at least three disease genes. Artificial susceptibility loci, each containing 100 genes, were constructed around each disease gene, and we used the network to rank these genes on the basis of their functional interactions. By following up the top five genes per artificial locus, we were able to detect at least one known disease gene in 54% of the loci studied, representing a 2.8-fold increase over random selection. This suggests that our method can significantly reduce the cost and effort of pinpointing true disease genes in analyses of disorders for which numerous loci have been reported but for which most of the genes are unknown.},
affiliation = {Complex Genetics Section, Department of Biomedical Genetics-Department of Medical Genetics, University Medical Centre Utrecht, Utrecht, The Netherlands.},
number = {6},
pages = {1011--25},
volume = {78},
year = {2006},
month = {Jun},
language = {eng},
keywords = {Genome: Human, Humans, Genetic Predisposition to Disease, Databases: Genetic, Computational Biology, Genetic Diseases: Inborn},
date-added = {2010-01-13 23:09:08 +0100},
date-modified = {2010-01-13 23:09:08 +0100},
doi = {10.1086/504300},
pii = {S0002-9297(07)63922-6},
pmid = {16685651},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Franke-2006-American%20Journal%20of%20Human%20Genetics_Reconstruction%20of%20a.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p2977},
rating = {0}
}

@article{Dalgleish:1999p1356,
author = {T Dalgleish and M Power},
title = {Cognition and emotion: Future directions},
year = {1999},
date-added = {2010-01-07 11:43:50 +0100},
date-modified = {2010-01-07 11:44:44 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Dalgleish-1999-_Cognition%20and%20emotio.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p1356},
rating = {0}
}

@article{Kang:2010p10034,
author = {Hyun Min Kang and Jae Hoon Sul and Susan K Service and Noah A Zaitlen and Sit-Yee Kong and Nelson B Freimer and Chiara Sabatti and Eleazar Eskin},
journal = {Nat Genet},
title = {Variance component model to account for sample structure in genome-wide association studies},
abstract = {Although genome-wide association studies (GWASs) have identified numerous loci associated with complex traits, imprecise modeling of the genetic relatedness within study samples may cause substantial inflation of test statistics and possibly spurious associations. Variance component approaches, such as efficient mixed-model association (EMMA), can correct for a wide range of sample structures by explicitly accounting for pairwise relatedness between individuals, using high-density markers to model the phenotype distribution; but such approaches are computationally impractical. We report here a variance component approach implemented in publicly available software, EMMA eXpedited (EMMAX), that reduces the computational time for analyzing large GWAS data sets from years to hours. We apply this method to two human GWAS data sets, performing association analysis for ten quantitative traits from the Northern Finland Birth Cohort and seven common diseases from the Wellcome Trust Case Control Consortium. We find that EMMAX outperforms both principal component analysis and genomic control in correcting for sample structure.},
affiliation = {[1] Center for Statistical Genetics, Department of Biostatistics, University of Michigan, Ann Arbor, Michigan, USA. [2] Center for Computational Medicine and Bioinformatics, The University of Michigan Medical School, Ann Arbor, Michigan, USA. [3] These authors contributed equally to this work.},
number = {4},
pages = {348--54},
volume = {42},
year = {2010},
month = {Apr},
language = {eng},
date-added = {2010-03-31 20:03:18 +0200},
date-modified = {2010-03-31 20:03:18 +0200},
doi = {10.1038/ng.548},
pii = {ng.548},
pmid = {20208533},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Kang-2010-Nat%20Genet_Variance%20component%20m.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p10034},
rating = {0}
}

@article{Meyer:2008p11611,
author = {Patrick E Meyer and Fr{\'e}d{\'e}ric Lafitte and Gianluca Bontempi},
journal = {BMC Bioinformatics},
title = {minet: A R/Bioconductor package for inferring large transcriptional networks using mutual information},
abstract = {RESULTS: This paper presents the R/Bioconductor package minet (version 1.1.6) which provides a set of functions to infer mutual information networks from a dataset. Once fed with a microarray dataset, the package returns a network where nodes denote genes, edges model statistical dependencies between genes and the weight of an edge quantifies the statistical evidence of a specific (e.g transcriptional) gene-to-gene interaction. Four different entropy estimators are made available in the package minet (empirical, Miller-Madow, Schurmann-Grassberger and shrink) as well as four different inference methods, namely relevance networks, ARACNE, CLR and MRNET. Also, the package integrates accuracy assessment tools, like F-scores, PR-curves and ROC-curves in order to compare the inferred network with a reference one. CONCLUSION: The package minet provides a series of tools for inferring transcriptional networks from microarray data. It is freely available from the Comprehensive R Archive Network (CRAN) as well as from the Bioconductor website.},
affiliation = {Machine Learning Group, Computer Science Department, Faculty of Science, Universit{\'e} Libre de Bruxelles, 1050 Brussels, Belgium. pmeyer@ulb.ac.be},
pages = {461},
volume = {9},
year = {2008},
month = {Jan},
language = {eng},
keywords = {Software, Oligonucleotide Array Sequence Analysis, Pattern Recognition: Automated, Models: Statistical, Internet, Algorithms, ROC Curve, Reproducibility of Results, Transcription: Genetic, Programming Languages, Data Interpretation: Statistical, Computational Biology, Gene Expression Profiling, False Positive Reactions},
date-added = {2010-05-11 21:41:18 +0200},
date-modified = {2010-05-11 21:41:18 +0200},
doi = {10.1186/1471-2105-9-461},
pii = {1471-2105-9-461},
pmid = {18959772},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Meyer-2008-BMC%20Bioinformatics_minet%20A%20RBioconduc.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p11611},
rating = {0}
}

@article{Clemmensen:2008p1809,
author = {L Clemmensen and T Hastie and B Ersboll},
title = {Sparse Discriminant Analysis},
abstract = {Classification in high-dimensional feature spaces where interpreta- tion and dimension reduction are of great importance is common in biological and medical applications. For these applications standard methods as microarrays, 1D NMR, and spectroscopy have become everyday tools for measuring thousands of features in samples of interest. Furthermore, the samples are often costly and therefore many such problems have few observations in relation to the number of features. Traditionally such data are analyzed by first performing a feature selection before classification. We propose a method which performs linear discriminant analysis with a sparseness criterion imposed such that the classification, feature selection and dimension reduction is merged into one analysis. The sparse discriminant analysis is faster than traditional feature selection methods based on computationally heavy criteria such as Wilk's lambda, and the results are better with regards to classification rates and sparseness. The method is extended to mixtures of Gaussians which is useful when e.g. biological clusters are present within each class. Finally, the methods proposed provide low-dimensional views of the discriminative directions.},
year = {2008},
date-added = {2010-01-09 21:51:19 +0100},
date-modified = {2010-01-09 21:52:39 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Clemmensen-2008-_Sparse%20Discriminant.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p1809},
rating = {0}
}

@article{Potkin:2009p3510,
author = {S G Potkin and J A Turner and J A Fallon and A Lakatos and D B Keator and G Guffanti and F Macciardi},
journal = {Mol Psychiatry},
title = {Gene discovery through imaging genetics: identification of two novel genes associated with schizophrenia},
abstract = {We have discovered two genes, RSRC1 and ARHGAP18, associated with schizophrenia and in an independent study provided additional support for this association. We have both discovered and verified the association of two genes, RSRC1 and ARHGAP18, with schizophrenia. We combined a genome-wide screening strategy with neuroimaging measures as the quantitative phenotype and identified the single nucleotide polymorphisms (SNPs) related to these genes as consistently associated with the phenotypic variation. To control for the risk of false positives, the empirical P-value for association significance was calculated using permutation testing. The quantitative phenotype was Blood-Oxygen-Level Dependent (BOLD) Contrast activation in the left dorsal lateral prefrontal cortex measured during a working memory task. The differential distribution of SNPs associated with these two genes in cases and controls was then corroborated in a larger, independent sample of patients with schizophrenia (n=82) and healthy controls (n=91), thus suggesting a putative etiological function for both genes in schizophrenia. Up until now these genes have not been linked to any neuropsychiatric illness, although both genes have a function in prenatal brain development. We introduce the use of functional magnetic resonance imaging activation as a quantitative phenotype in conjunction with genome-wide association as a gene discovery tool.},
affiliation = {Department of Psychiatry and Human Behavior, Brain Imaging Center, University of California, Irvine, CA 92617, USA. sgpotkin@uci.edu},
number = {4},
pages = {416--28},
volume = {14},
year = {2009},
month = {Apr},
language = {eng},
keywords = {Tumor Suppressor Proteins, Adult, Oxygen, Nuclear Proteins, Humans, Genotype, Prefrontal Cortex, Middle Aged, Polymorphism: Single Nucleotide, Male, GTPase-Activating Proteins, Genetic Testing, Young Adult, Aged, Female, Adolescent, Gene Frequency, Genome-Wide Association Study, Schizophrenia, Magnetic Resonance Imaging, Genetic Predisposition to Disease, Image Processing: Computer-Assisted},
date-added = {2010-01-15 15:47:04 +0100},
date-modified = {2010-01-15 15:47:04 +0100},
doi = {10.1038/mp.2008.127},
pii = {mp2008127},
pmid = {19065146},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p3510},
rating = {0}
}

@article{Stout:2003p3685,
author = {W Stout and D Bolt and A G Froelich and B HabingS Hartz and L Roussos},
title = {Development of a SIBTEST bundle methodology for improving test equity with applications for GRE test development},
year = {2003},
date-added = {2010-01-16 20:22:41 +0100},
date-modified = {2010-01-16 20:23:54 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Stout-2003-_Development%20of%20a%20SIB.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p3685},
rating = {0}
}

@article{Perreault:2010p6619,
author = {Michel Perreault and No{\'e} Djawn White and Eric Fabr{\`e}s and Michel Landry and Ann{\'e}lie S Anestin and Daniel Rabouin},
journal = {Evaluation and program planning},
title = {Relationship between perceived improvement and treatment satisfaction among clients of a methadone maintenance program},
abstract = {PURPOSE: The objective of this study was to evaluate the relationship between perceived improvement and client satisfaction in a methadone maintenance treatment population. A secondary objective was to evaluate the psychometric properties of the Perceived Improvement Questionnaire (PIQ). DATA SOURCES/STUDY SETTING: Two hundred and thirty-two clients of a methadone maintenance treatment program filled out self-reported questionnaires and two open-ended questions measuring their perceived improvement and their level of satisfaction with the services received. PRINCIPAL FINDINGS: Correlation analyses revealed a significant relationship between participants' perceived improvement and their level of satisfaction with services received throughout their treatment. A factor analysis identified 3 sub-scales of the PIQ: emotional health, social relations and physical health. The PIQ's internal consistency and construct validity supported the adequacy of the metric properties of the questionnaire. CONCLUSION: Further research is needed to investigate the link between clients' input and treatment satisfaction in different substance abuse populations. The scale's potential to provide valuable information such as clinical assessment and program evaluation should be explored.},
affiliation = {Douglas University Institute, 6875 Boul. LaSalle, Montr{\'e}al, Qu{\'e}bec, Canada, H4H 1R3; Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montr{\'e}al, Qu{\'e}bec, Canada, H3A 1A1.},
pages = {},
year = {2010},
month = {Jan},
language = {ENG},
date-added = {2010-03-03 20:29:54 +0100},
date-modified = {2010-03-03 20:29:54 +0100},
doi = {10.1016/j.evalprogplan.2009.12.003},
pii = {S0149-7189(09)00121-9},
pmid = {20089307},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Perreault-2010-Evaluation%20and%20program%20planning_Relationship%20between.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p6619},
rating = {0}
}

@article{Zinbarg:2006p11666,
author = {R E Zinbarg and I Yovel and W Revelle and R P McDonald},
journal = {Applied Psychological Measurement},
title = {Estimating Generalizability to a Latent Variable Common to All of a Scale's Indicators: A Comparison of Estimators for ωh},
abstract = {The extent to which a scale score generalizes to a latent variable common to all of the scale's indicators is indexed by the scale's general factor saturation. Seven techniques for estimating this parameter---omegahierarchical (ωh)---are compared in a series of simulated data sets. Primary comparisons were based on 160 artificial data sets simulating perfectly simple and symmetric structures that contained four group factors, and an additional 200 artificial data sets confirmed large standard deviations for two methods in these simulations when a general factor was absent. Major findings were replicated in a series of 40 additional artificial data sets based on the structure of a real scale widely believed to contain three group factors of unequal size and less than perfectly simple structure. The results suggest that alpha and methods based on either the first unrotated principal factor or component should be rejected as estimates of ωh .},
number = {2},
pages = {121--144},
volume = {30},
year = {2006},
date-added = {2010-05-14 20:53:28 +0200},
date-modified = {2010-05-14 20:55:24 +0200},
doi = {10.1177/0146621605278814},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Zinbarg-2006-Applied%20Psychological%20Measurement_Estimating%20Generaliz.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p11666},
rating = {0}
}

@article{Loh:2002p1609,
author = {W-Y Loh},
journal = {Statistica Sinica},
title = {Regression Trees With Unbiased Variable Selection and Interaction Detection},
abstract = {We propose an algorithm for regression tree construction called GUIDE. It is specifically designed to eliminate variable selection bias, a problem that can undermine the reliability of inferences from a tree structure. GUIDE controls bias by employing chi-square analysis of residuals and bootstrap calibration of significance probabilities. This approach allows fast compu- tation speed, natural extension to data sets with categorical variables, and direct detection of local two-variable interactions. Previous algorithms are not unbiased and are insensitive to local interactions during split selection. The speed of GUIDE enables two further enhancements---complex model- ing at the terminal nodes, such as polynomial or best simple linear models, and bagging. In an experiment with real data sets, the prediction mean square error of the piecewise constant GUIDE model is within $\pm$20% of that of CART	. Piecewise linear GUIDE models are more accurate; with bagging they can outperform the spline-based MARS	method.},
pages = {361--386},
volume = {12},
year = {2002},
date-added = {2010-01-07 17:04:51 +0100},
date-modified = {2010-07-29 19:50:42 +0200},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Loh-2002-Statistica%20Sinica_Regression%20Trees%20Wit.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p1609},
rating = {0}
}

@article{Aakvik:2010p6900,
author = {H Aakvik and J J Heckman and E J Vytlacil},
title = {Local instrumental variables and latent variable models for estimating treatment effects},
date-added = {2010-03-06 11:54:43 +0100},
date-modified = {2010-07-29 17:06:22 +0200},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Aakvik--_Local%20instrumental%20v.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p6900},
read = {Yes},
rating = {3}
}

@article{Costello:2005p11711,
author = {A B Costello and J W Osborne},
journal = {Practical Assessment Research {\&} Evaluation},
title = {Best Practices in Exploratory Factor Analysis: Four Recommendations for Getting the Most From Your Analysis},
abstract = {Exploratory factor analysis (EFA) is a complex, multi-step process. The goal of this paper is to collect, in one article, information that will allow researchers and practitioners to understand the various choices available through popular software packages, and to make decisions about ``best practices'' in exploratory factor analysis. In particular, this paper provides practical information on making decisions regarding (a) extraction, (b) rotation, (c) the number of factors to interpret, and (d) sample size.},
number = {7},
volume = {10},
year = {2005},
date-added = {2010-05-14 21:33:29 +0200},
date-modified = {2010-07-29 19:44:42 +0200},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Costello-2005-Practical%20Assessment%20Research%20%20&%20Evaluation_Best%20Practices%20in%20Ex.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p11711},
rating = {0}
}

@article{Popovici:2010p12457,
author = {Vlad Popovici and Weijie Chen and Brandon G Gallas and Christos Hatzis and Weiwei Shi and Frank W Samuelson and Yuri Nikolsky and Marina Tsyganova and Alex Ishkin and Tatiana Nikolskaya and Kenneth R Hess and Vicente Valero and Daniel Booser and Mauro Delorenzi and Gabriel N Hortobagyi and Leming Shi and W Fraser Symmans and Lajos Pusztai},
journal = {Breast Cancer Res},
title = {Effect of training-sample size and classification difficulty on the accuracy of genomic predictors},
abstract = {INTRODUCTION: As part of the MicroArray Quality Control (MAQC)-II project, this analysis examines how the choice of univariate feature-selection methods and classification algorithms may influence the performance of genomic predictors under varying degrees of prediction difficulty represented by three clinically relevant endpoints. METHODS: We used gene-expression data from 230 breast cancers (grouped into training and independent validation sets), and we examined 40 predictors (five univariate feature-selection methods combined with eight different classifiers) for each of the three endpoints. Their classification performance was estimated on the training set by using two different resampling methods and compared with the accuracy observed in the independent validation set. RESULTS: A ranking of the three classification problems was obtained, and the performance of 120 models was estimated and assessed on an independent validation set. The bootstrapping estimates were closer to the validation performance than were the cross-validation estimates. The required sample size for each endpoint was estimated, and both gene-level and pathway-level analyses were performed on the obtained models. CONCLUSIONS: We showed that genomic predictor accuracy is determined largely by an interplay between sample size and classification difficulty. Variations on univariate feature-selection methods and choice of classification algorithm have only a modest impact on predictor performance, and several statistically equally good predictors can be developed for any given classification problem.},
affiliation = {Bioinformatics Core Facility, Swiss Institute of Bioinformatics, G{\'e}nopode Building, Quartier Sorge, Lausanne CH-1015, Switzerland.},
number = {1},
pages = {R5},
volume = {12},
year = {2010},
month = {Jan},
language = {eng},
date-added = {2010-06-15 17:34:53 +0200},
date-modified = {2010-06-15 17:34:54 +0200},
doi = {10.1186/bcr2468},
pii = {bcr2468},
pmid = {20064235},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Popovici-2010-Breast%20Cancer%20Res_Effect%20of%20training-s.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p12457},
rating = {0}
}

@article{Zakzanis:2001p14219,
author = {K K Zakzanis},
journal = {Arch Clin Neuropsychol},
title = {Statistics to tell the truth, the whole truth, and nothing but the truth: formulae, illustrative numerical examples, and heuristic interpretation of effect size analyses for neuropsychological researchers},
abstract = {If, as neuropsychologists, we think of the relationship between brain and behavior as the same as that between truth and reality, we must be equipped with statistical procedures that are coherent in terms of what we measure and what it represents. I believe that this necessary statistical procedure is effect size analysis, and without it, I believe that we fail to tell the truth, the whole truth, and nothing but the truth when describing our neuropsychological research. Accordingly, I review here the standard calculations of commonly employed effect sizes in two group designs and show how to adjust some familiar (and perhaps not so familiar) formulae using illustrative numerical examples. I also put forth an argument to adopt Cohen's measure as an expression of effect size based on its apropos to neuropsychological research. It is also argued that the interpretation of the magnitude of an effect size should depend on context, and not on pre-established heuristic benchmarks. It is noted, however, that effect sizes greater than 3.0 (OL%<5) might seem particularly appropriate when evaluating the sensitivity of neuropsychological tasks and in establishing test markers in neuropsychological disorders.},
affiliation = {Division of Life Sciences, University of Toronto, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4. zakzanis@scar.utoronto.ca},
number = {7},
pages = {653--67},
volume = {16},
year = {2001},
month = {Oct},
language = {eng},
date-added = {2010-08-22 20:56:25 +0200},
date-modified = {2010-08-22 20:56:33 +0200},
pii = {S0887-6177(00)00076-7},
pmid = {14589784},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Zakzanis-2001-Arch%20Clin%20Neuropsychol_Statistics%20to%20tell%20t.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p14219},
rating = {3}
}

@article{Brose:2009p11809,
author = {Leonie S Brose and Clare Bradley},
journal = {Value Health},
title = {Psychometric Development of the Individualized Retinopathy-Dependent Quality of Life Questionnaire (RetDQoL)},
abstract = {ABSTRACT Objectives: Psychometric development of the Retinopathy-Dependent Quality of Life (RetDQoL) questionnaire in a cross-sectional study of 207 German patients with diabetic retinopathy. Forty patients (19%) also had clinically significant macular edema. Methods: Principal component analyses identified factor structure, and Cronbach's alpha assessed internal consistencies. Construct validity was examined by testing the additional impact of macular edema and expected relationships of RetDQoL scores with visual impairment, stage of diabetic retinopathy, subscales of the SF-12, and scores of the Retinopathy Treatment Satisfaction Questionnaire (RetTSQ). Analyses were conducted using the RetDQoL's AWI score (average weighted impact of diabetic retinopathy on 26 life domains) and its two overview items (present QoL in general and retinopathy-specific QoL). Content validity was investigated using an open-ended question to identify any additional items needed. Results: A forced one-factor solution of the 26 specific weighted impact ratings showed all items except working life (applicable to 27%) to load >0.55, and Cronbach's alpha was 0.96, showing very high reliability. Greater impairment, worse diabetic retinopathy, and macular edema were associated with greater negative impact on scores. AWI correlated as expected more highly with retinopathy-specific QoL (r = 0.71, P < 0.01) than with present QoL (r = 0.28, P < 0.01). RetDQoL scores correlated moderately with SF-12 subscales (r = 0.22-0.51, P < 0.01) and RetTSQ scores (r = 0.27-0.51, P < 0.01). For six domains, >60% of patients reported no impact. No additional domains were needed. Conclusions: The RetDQoL is valid and reliable for patients with diabetic retinopathy with or without macular edema. It may be shortened if findings are confirmed cross-culturally.},
affiliation = {Royal Holloway, University of London, Egham, Surrey, UK.},
pages = {},
year = {2009},
month = {Aug},
language = {ENG},
date-added = {2010-05-23 10:43:52 +0200},
date-modified = {2010-05-23 10:43:52 +0200},
doi = {10.1111/j.1524-4733.2009.00589.x},
pii = {VHE589},
pmid = {19695003},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Brose-2009-Value%20Health_Psychometric%20Develop.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p11809},
rating = {0}
}

@article{Revicki:1995p9557,
author = {D A Revicki and A W Wu and M I Murray},
journal = {Med Care},
title = {Change in clinical status, health status, and health utility outcomes in HIV-infected patients},
abstract = {Psychometric health status scales and health utility scales were compared to measure the impact of changes in clinical status in patients infected with the human immunodeficiency virus (HIV). The data used included the first two waves of a longitudinal study of 160 HIV-infected patients, a population that was 34% women and 65% African American. The Medical Outcome Study-HIV Health Survey (MOS-HIV); sleep, cognitive function, and depression scales; the Sickness Impact Profile Home Management Scale; and questions on HIV-related clinical symptoms were administered. Standard gamble utilities and categorical rating scale preferences were assessed for current health state. The MOS-HIV scale scores of asymptomatic patients were significantly higher than those of symptomatic patients and patients with acquired immune deficiency syndrome. No differences were observed for utilities. Increases in clinical symptoms over 4 months were associated with changes in health perception, pain, physical role function, social function, mental health, depression, energy, cognitive function, and categorical rating scale preferences. The MOS-HIV and other health status measures discriminated between HIV disease stages and were associated with clinical status. Standard gamble utilities did not discriminate among the three groups and were not correlated with clinical status.},
affiliation = {Medical Technology Assessment Program, Battelle Centers for Public Health Research and Evaluation, Arlington, VA 22201, USA.},
number = {4 Suppl},
pages = {AS173--82},
volume = {33},
year = {1995},
month = {Apr},
language = {eng},
keywords = {Female, Acquired Immunodeficiency Syndrome, Quality of Life, Adult, Longitudinal Studies, Humans, Severity of Illness Index, Health Status Indicators, Health Status, Psychometrics, Male, Outcome Assessment (Health Care)},
date-added = {2010-03-23 20:53:42 +0100},
date-modified = {2010-07-29 19:39:29 +0200},
pmid = {7723445},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p9557},
rating = {0}
}

@article{Comeau:2001p12181,
author = {N Comeau and S H Stewart and P Loba},
journal = {Addict Behav},
title = {The relations of trait anxiety, anxiety sensitivity, and sensation seeking to adolescents' motivations for alcohol, cigarette, and marijuana use},
abstract = {The present study investigated relations of anxiety sensitivity and other theoretically relevant personality factors to Copper's [Psychological Assessment 6 (1994) 117.] four categories of substance use motivations as applied to teens' use of alcohol, cigarettes, and marijuana. A sample of 508 adolescents (238 females, 270 males; mean age = 15.1 years) completed the Trait subscale of the State-Trait Anxiety Inventory for Children, the Childhood Anxiety Sensitivity Index (CASI), and the Intensity and Novelty subscales of the Arnett Inventory of Sensation Seeking. Users of each substance also completed the Drinking Motives Questionnaire-Revised (DMQ-R) and/or author-compiled measures for assessing motives for cigarette smoking and marijuana use, respectively. Multiple regression analyses revealed that, in the case of each drug, the block of personality variables predicted "risky" substance use motives (i.e., coping, enhancement, and/or conformity motives) over-and-above demographics. High intensity seeking and low anxiety sensitivity predicted enhancement motives for alcohol use, high anxiety sensitivity predicted conformity motives for alcohol and marijuana use, and high trait anxiety predicted coping motives for alcohol and cigarette use. Moreover, anxiety sensitivity moderated the relation between trait anxiety and coping motives for alcohol and cigarette use: the trait anxiety-coping motives relation was stronger for high, than for low, anxiety sensitive individuals. Implications of the findings for improving substance abuse prevention efforts for youth will be discussed.},
affiliation = {Department of Philosophy, Dalhousie University, Halifax, Nova Scotia, Canada. ncomeau@is2.dal.ca},
number = {6},
pages = {803--25},
volume = {26},
year = {2001},
month = {Jan},
language = {eng},
keywords = {Motivation, Humans, Male, Risk-Taking, Arousal, Adult, Alcohol Drinking, Stress: Psychological, Personality Assessment, Adolescent, Marijuana Smoking, Smoking, Female, Anxiety Disorders},
date-added = {2010-05-30 10:44:48 +0200},
date-modified = {2010-05-30 10:44:49 +0200},
pmid = {11768546},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p12181},
rating = {0}
}

@article{Dickinson:2009p5834,
author = {D Dickinson and B Elvev{\aa}g},
journal = {Neuroscience},
title = {Genes, cognition and brain through a COMT lens},
abstract = {Various genes are known to modulate the delicate balance of dopamine in prefrontal cortex and influence cortical information processing. Catechol-O-methyltransferase (COMT) on chromosome 22q11 is the most widely studied of these genes. Val158Met, a common, functional variant in the coding sequence that increases or decreases the enzymatic activity of the gene has been shown to impact the efficiency of prefrontally-mediated cognition, specifically executive functioning, working memory, fluid intelligence and attentional control. We review the rapidly evolving literature exploring the association between COMT genotype and cognitive performance, and illustrate how this polymorphism has served a pivotal role in characterizing various interacting dimensions of complexity in the relationship between genes and cognition. We review how Val158Met has been used to help develop and validate behavioral and neurophysiological phenotypes, as a critical tool in dissecting overlapping neural functional systems and exploring interactions within and between genes, and in exploring how gene effects on cognition are modulated by environmental, demographic and developmental factors. Despite the impressive range of findings, the COMT story is also a bracing reminder of how much work remains to translate this knowledge into practical clinical applications.},
affiliation = {Clinical Brain Disorders Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA. Dwight.Dickinson@nih.gov},
note = {genim},
number = {1},
pages = {72--87},
volume = {164},
year = {2009},
month = {Nov},
language = {eng},
keywords = {Animals, Brain, Phenotype, Emotions, Humans, Environment, Prefrontal Cortex, Cognition, Catechol O-Methyltransferase},
date-added = {2010-02-17 10:12:14 +0100},
date-modified = {2010-02-17 10:30:29 +0100},
doi = {10.1016/j.neuroscience.2009.05.014},
pii = {S0306-4522(09)00796-9},
pmid = {19446012},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Dickinson-2009-Neuroscience_Genes%20cognition%20and.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p5834},
rating = {0}
}

@article{BenetMartinez:1998p5175,
author = {V Benet-Martinez and O P John},
journal = {J Pers Soc Psychol},
title = {Los Cinco Grandes across cultures and ethnic groups: multitrait multimethod analyses of the Big Five in Spanish and English},
abstract = {Spanish-language measures of the Big Five personality dimensions are needed for research on Hispanic minority populations. Three studies were conducted to evaluate a Spanish version of the Big Five Inventory (BFI) (O. P. John et al., 1991) and explore the generalizability of the Big Five factor structure in Latin cultural groups. In Study 1, a cross-cultural design was used to compare the Spanish and English BFI in college students from Spain and the United States, to assess factor congruence across languages, and to test convergence with indigenous Spanish Big Five markers. In Study 2, a bilingual design was used to compare the Spanish and English BFI in a college-educated sample of bilingual Hispanics and to test convergent and discriminant validity across the two languages as well as with the NEO Five Factor Inventory in both English and Spanish. Study 3 replicated the BFI findings from Study 2 in a working-class Hispanic bilingual sample. Results show that (a) the Spanish BFI may serve as an efficient, reliable, and factorially valid measure of the Big Five for research on Spanish-speaking individuals and (b) there is little evidence for substantial cultural differences in personality structure at the broad level of abstraction represented by the Big Five dimensions.},
affiliation = {Department of Psychology, University of Michigan, Ann Arbor 48109, USA. veronica@umich.edu},
number = {3},
pages = {729--50},
volume = {75},
year = {1998},
month = {Sep},
language = {eng},
keywords = {Hispanic Americans, Personality Inventory, Cross-Cultural Comparison, Humans, California, Translating, Factor Analysis: Statistical, Cultural Characteristics, Reproducibility of Results, Psychometrics, Female, Male, Spain, Adult, Discriminant Analysis, Students},
date-added = {2010-02-07 12:40:16 +0100},
date-modified = {2010-07-29 20:44:44 +0200},
pmid = {9781409},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Benet-Martinez-1998-J%20Pers%20Soc%20Psychol_Los%20Cinco%20Grandes%20ac.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p5175},
rating = {0}
}

@article{Mapuranga:2008p4116,
author = {R Mapuranga and NJ Dorans and K Middleton},
journal = {AERA},
title = {A Review of Recent Developments in Differential Item Functioning},
abstract = {In many practical settings, essentially the same differential item functioning (DIF) procedures have been in use since the late 1980s. Since then, examinee populations have become more heterogeneous, and tests have included more polytomously-scored items. This paper summarizes and classifies new DIF methods and procedures that have appeared since the early 1990s and assesses their appropriateness for practical use. Widely-used DIF methods are evaluated alongside these new methods for completeness, clarity and comparability.},
affiliation = {ETS, Princeton, NJ},
year = {2008},
date-added = {2010-01-20 00:03:51 +0100},
date-modified = {2010-01-20 00:04:52 +0100},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Mapuranga-2008-AERA_A%20Review%20of%20Recent%20D.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p4116},
rating = {0}
}

@article{Calhoun:2009p5773,
author = {Vince D Calhoun and Jingyu Liu and T{\"u}lay Adali},
journal = {Neuroimage},
title = {A review of group ICA for fMRI data and ICA for joint inference of imaging, genetic, and ERP data},
abstract = {Independent component analysis (ICA) has become an increasingly utilized approach for analyzing brain imaging data. In contrast to the widely used general linear model (GLM) that requires the user to parameterize the data (e.g. the brain's response to stimuli), ICA, by relying upon a general assumption of independence, allows the user to be agnostic regarding the exact form of the response. In addition, ICA is intrinsically a multivariate approach, and hence each component provides a grouping of brain activity into regions that share the same response pattern thus providing a natural measure of functional connectivity. There are a wide variety of ICA approaches that have been proposed, in this paper we focus upon two distinct methods. The first part of this paper reviews the use of ICA for making group inferences from fMRI data. We provide an overview of current approaches for utilizing ICA to make group inferences with a focus upon the group ICA approach implemented in the GIFT software. In the next part of this paper, we provide an overview of the use of ICA to combine or fuse multimodal data. ICA has proven particularly useful for data fusion of multiple tasks or data modalities such as single nucleotide polymorphism (SNP) data or event-related potentials. As demonstrated by a number of examples in this paper, ICA is a powerful and versatile data-driven approach for studying the brain.},
affiliation = {The Mind Research Network, Albuquerque, NM 87131, USA. vcalhoun@unm.edu},
number = {1 Suppl},
pages = {S163--72},
volume = {45},
year = {2009},
month = {Mar},
language = {eng},
keywords = {Principal Component Analysis, Magnetic Resonance Imaging, Brain, Polymorphism: Single Nucleotide, Humans, Image Processing: Computer-Assisted, Evoked Potentials},
date-added = {2010-02-17 10:07:47 +0100},
date-modified = {2010-02-17 10:07:47 +0100},
doi = {10.1016/j.neuroimage.2008.10.057},
pii = {S1053-8119(08)01203-2},
pmid = {19059344},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Calhoun-2009-Neuroimage_A%20review%20of%20group%20IC.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p5773},
rating = {0}
}

@article{Wainwright:2004p12678,
author = {Mark Wainwright and Margaret J Wright and Gina M Geffen and Laurie B Geffen and Michelle Luciano and Nicholas G Martin},
journal = {Behav Genet},
title = {Genetic and environmental sources of covariance between reading tests used in neuropsychological assessment and IQ subtests},
abstract = {In this study, we examined genetic and environmental influences on covariation among two reading tests used in neuropsychological assessment (Cambridge Contextual Reading Test [CCRT], [Beardsall, L., and Huppert, F. A. (1994). J. Clin. Exp. Neuropsychol. 16:232-242], Schonell Graded Word Reading Test [SGWRT], [Schonell, F. J., and Schonell, P. E. (1960). Diagnostic and attainment testing. Edinburgh: Oliver and Boyd.]) and among a selection of IQ subtests from the Multidimensional Aptitude Battery (MAB), [Jackson, D. N. (1984). Multidimensional aptitude battery, Ontario: Research Psychologists Press.] and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) [Wechsler, D. (1981). Manual for the Wechsler Adult Intelligence Scale-Revised (WAIS-R). San Antonio: The Psychological Corporation]. Participants were 225 monozygotic and 275 dizygotic twin pairs aged from 15 years to 18 years (mean, 16 years). For Verbal IQ subtests, phenotypic correlations with the reading tests ranged from 0.44 to 0.65. For Performance IQ subtests, phenotypic correlations with the reading tests ranged from 0.23 to 0.34. Results of Structural Equation Modeling (SEM) supported a model with one genetic General factor and three genetic group factors (Verbal, Performance, Reading). Reading performance was influenced by the genetic General factor (accounting for 13% and 20% of the variance for the CCRT and SGWRT, respectively), the genetic Verbal factor (explaining 17% and 19% of variance for the CCRT and SGWRT), and the genetic Reading factor (explaining 21% of the variance for both the CCRT and SGWRT). A common environment factor accounted for 25% and 14% of the CCRT and SGWRT variance, respectively. Genetic influences accounted for more than half of the phenotypic covariance between the reading tests and each of the IQ subtests. The heritabilities of the CCRT and SGWRT were 0.54 and 0.65, respectively. Observable covariance between reading assessments used by neuropsychologists to estimate IQ and IQ subtests appears to be largely due to genetic effects.},
affiliation = {Queensland Institute of Medical Research, Brisbane, Australia. markWa@qimr.edu.au},
number = {4},
pages = {365--76},
volume = {34},
year = {2004},
month = {Jul},
language = {eng},
keywords = {Adolescent, Neuropsychology, Sex Characteristics, Intelligence Tests, Female, Reading, Male, Twins: Dizygotic, Environment, Problem Solving, Models: Genetic, Humans, Analysis of Variance, Genetics: Medical, Twins: Monozygotic, Intelligence},
date-added = {2010-06-15 22:41:22 +0200},
date-modified = {2010-07-29 20:09:06 +0200},
doi = {10.1023/B:BEGE.0000023642.34853.cb},
pii = {485768},
pmid = {15082934},
local-url = {file://localhost/Users/chl/Dropbox/Papers/Wainwright-2004-Behav%20Genet_Genetic%20and%20environm.pdf},
uri = {papers://58407365-8DEB-4C7D-995B-6322E39C7022/Paper/p12678},
rating = {0}
}

@article{Kuo:2007p3535,
author = {Po-Hsiu Kuo and Michael C Neale and Brien P Riley and Diana G Patterson and Dermot Walsh and Carol A Prescott and Kenneth S Kendler},
journal = {Am J Med Genet B Neuropsychiatr Genet},
title = {A genome-wide linkage analysis for the personality trait neuroticism in the Irish affected sib-pair study of alcohol dependence},
abstract = {Neuroticism is a personality trait which reflects individual differences in emotional stability and vulnerability to stress and anxiety. Consistent evidence shows substantial genetic influences on variation in this trait. The present study seeks to identify regions containing susceptibility loci for neuroticism using a selected sib-pair sample from Ireland. Using Merlin regress, we conducted a 4 cM whole-genome linkage analysis on 714 sib-pairs. Evidence for linkage to neuroticism was found on chromosomes 11p, 12q, and 15q. The highest linkage peak was on 12q at marker D12S1638 with a Lod score of 2.13 (-log p = 2.76, empirical P-value <0.001). Our data also support gender specific loci for neuroticism, with male specific linkage regions on chromosomes 1, 4, 11, 12, 15, 16, and 22, and female specific linkage regions on chromosomes 2, 4, 9, 12, 13, and 18. Some genome regions reported in the present study replicate findings from previous linkage studies of neuroticism. These results, together with prior studies, indicate several potential regions for quantitative trait loci for neuroticism that warrant further study.},
affiliation = {Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University, Richmond, Virginia 23298-0126, USA. pkuo@vcu.edu},
number = {4},
pages = {463--8},
volume = {144B},
year = {2007},
month = {Jun},
language = {eng},
keywords = {Sex Characteristics, Personality, Linkage (Genetics), Genetic Markers, Alcoholism, Ireland, Siblings, Male, Neurotic Disorders, Female, European Continental Ancestry Group, Humans, Genome: Human},
date-added = {2010-01-15 20:51:10 +0100},
date-modified = {2010-01-15 20:51:10 +0100},
doi = {10.1002/ajmg.b.30478},
pmid = {17427203},
uri = {papers://58407365-8DEB-4C7D

license: MIT

license_type: permissive

branch_name: refs/heads/master

extension: bib