1. Harmonizing Measures of Cognitive Performance Across International Surveys of Aging Using Item Response Theory.
- Author
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Chan KS, Gross AL, Pezzin LE, Brandt J, and Kasper JD
- Subjects
- Aged, Aged, 80 and over, Female, Humans, Longitudinal Studies, Male, Psychological Theory, Reproducibility of Results, United Kingdom, United States, Aging psychology, Cognition physiology, Internationality, Surveys and Questionnaires
- Abstract
Objective: To harmonize measures of cognitive performance using item response theory (IRT) across two international aging studies., Method: Data for persons ≥65 years from the Health and Retirement Study (HRS, N = 9,471) and the English Longitudinal Study of Aging (ELSA, N = 5,444). Cognitive performance measures varied (HRS fielded 25, ELSA 13); 9 were in common. Measurement precision was examined for IRT scores based on (a) common items, (b) common items adjusted for differential item functioning (DIF), and (c) DIF-adjusted all items., Results: Three common items (day of date, immediate word recall, and delayed word recall) demonstrated DIF by survey. Adding survey-specific items improved precision but mainly for HRS respondents at lower cognitive levels., Discussion: IRT offers a feasible strategy for harmonizing cognitive performance measures across other surveys and for other multi-item constructs of interest in studies of aging. Practical implications depend on sample distribution and the difficulty mix of in-common and survey-specific items., (© The Author(s) 2015.)
- Published
- 2015
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