Short-term consistency in self-reported physical functioning among elderly women: The women's health and aging study

Paul J. Rathouz, Judith D. Kasper, Scott L. Zeger, Luigi Ferrucci, Karen Bandeen-Roche, Diana L Miglioretti, Linda P. Fried

Research output: Contribution to journalArticle

47 Scopus citations

Abstract

The assessment of physical functioning and disability is integral to population-based and clinical research carried out among elderly people. Typically, functional status is measured through self-reported responses to questions of the form 'Do you have difficulty [doing a specific task]?' Knowledge of the reliability and validity of these self-report measures is key to the interpretation of many research efforts, but data on these measurement parameters are sparse. This paper addresses this deficiency through analyses of data from the Weekly Substudy of the Women's Health and Aging Study, a cohort of Baltimore-area women aged ≤65 years with moderate to severe physical disability. Self-reported data on 20 activities, obtained weekly over a 6-month period in 1993 or 1994, were analyzed to investigate how time intervals between assessments and a subject's age and baseline level of disability influenced the consistency of self-reports of disability at both the population level and the individual level. The prevalence of self- reported difficulty increased with baseline disability and, to a lesser extent, with age group. Consistency for all items was very high over short time intervals, but it decreased substantially with increasing intervals between responses (although associations between responses remained significant at 24 weeks). Consistency did not vary with age or baseline disability. Graphic techniques and statistical methods for use with repeated binary data are also illustrated.

Original languageEnglish (US)
Pages (from-to)764-773
Number of pages10
JournalAmerican Journal of Epidemiology
Volume147
Issue number8
StatePublished - Apr 15 1998
Externally publishedYes

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Keywords

  • Activities of daily living
  • Aged
  • Aging
  • Disability evaluation
  • Epidemiologic methods
  • Questionnaires
  • Women

ASJC Scopus subject areas

  • Epidemiology

Cite this

Rathouz, P. J., Kasper, J. D., Zeger, S. L., Ferrucci, L., Bandeen-Roche, K., Miglioretti, D. L., & Fried, L. P. (1998). Short-term consistency in self-reported physical functioning among elderly women: The women's health and aging study. American Journal of Epidemiology, 147(8), 764-773.