Harmonizing Measures of Cognitive Performance Across International Surveys of Aging Using Item Response Theory.

TitleHarmonizing Measures of Cognitive Performance Across International Surveys of Aging Using Item Response Theory.
Publication TypeJournal Article
Year of Publication2015
AuthorsChan, KS, Gross, AL, Pezzin, LE, Brandt, J, Kasper, JD
JournalJ Aging Health
Date Published2015 Dec
ISSN Number1552-6887
KeywordsAged, Aged, 80 and over, Aging, Cognition, Female, Humans, Internationality, Longitudinal Studies, Male, Psychological Theory, Reproducibility of Results, Surveys and Questionnaires, United Kingdom, United States

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.

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Endnote Keywords

ELSA_/item response theory/cognitive performance/Public Policy/Cognitive ability/Aging/cross-national comparison

Endnote ID


Alternate JournalJ Aging Health
Citation Key8277
PubMed ID26526748
PubMed Central IDPMC4834843
Grant ListP50 AG005146 / AG / NIA NIH HHS / United States
R21 AG032502 / AG / NIA NIH HHS / United States
AG032502 / AG / NIA NIH HHS / United States