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BACKGROUND The construction and evaluation of item banks to measure unidimensional constructs of health-related quality of life (HRQOL) is a fundamental objective of the Patient-Reported Outcomes Measurement Information System (PROMIS) project. OBJECTIVES Item banks will be used as the foundation for developing short-form instruments and enabling(More)
The Alzheimer Disease Genetics Consortium (ADGC) performed a genome-wide association study of late-onset Alzheimer disease using a three-stage design consisting of a discovery stage (stage 1) and two replication stages (stages 2 and 3). Both joint analysis and meta-analysis approaches were used. We obtained genome-wide significant results at MS4A4A(More)
BACKGROUND Alzheimer disease and other dementing disorders are major sources of morbidity and mortality in aging societies. Proven strategies to delay onset or reduce risk for dementing disorders would be greatly beneficial. OBJECTIVE To determine whether regular exercise is associated with a reduced risk for dementia and Alzheimer disease. DESIGN(More)
Logistic regression provides a flexible framework for detecting various types of differential item functioning (DIF). Previous efforts extended the framework by using item response theory (IRT) based trait scores, and by employing an iterative process using group-specific item parameters to account for DIF in the trait scores, analogous to purification(More)
We sought to develop and evaluate a composite memory score from the neuropsychological battery used in the Alzheimer’s Disease (AD) Neuroimaging Initiative (ADNI). We used modern psychometric approaches to analyze longitudinal Rey Auditory Verbal Learning Test (RAVLT, 2 versions), AD Assessment Schedule - Cognition (ADAS-Cog, 3 versions), Mini-Mental State(More)
This paper investigates comorbidity between chronic back and neck pain and other physical and mental disorders in the US population, and assesses the contributions of chronic spinal pain and comorbid conditions to role disability. A probability sample of US adults (n=5692) was interviewed. Chronic spinal pain, other chronic pain conditions and selected(More)
Candidate gene and genome-wide association studies (GWAS) have identified genetic variants that modulate risk for human disease; many of these associations require further study to replicate the results. Here we report the first large-scale application of the phenome-wide association study (PheWAS) paradigm within electronic medical records (EMRs), an(More)
CONTEXT Studies suggest that many survivors of critical illness experience long-term cognitive impairment but have not included premorbid measures of cognitive functioning and have not evaluated risk for dementia associated with critical illness. OBJECTIVES To determine whether decline in cognitive function was greater among older individuals who(More)
The Alzheimer’s Disease Neuroimaging Initiative (ADNI) measures abilities broadly related to executive function (EF), including WAIS-R Digit Symbol Substitution, Digit Span Backwards, Trails A and B, Category Fluency, and Clock Drawing. This study investigates whether a composite executive function measure based on these multiple indicators has better(More)
OBJECTIVE Measures of shoulder function may differ by dominance of affected shoulder, surgical history, gender, or race. We present a technique for determining whether observed differences in function between groups are due to biased test items or real differences in function. STUDY DESIGN AND SETTING Four hundred patients who were receiving(More)