TY - JOUR
T1 - Short-term consistency in self-reported physical functioning among elderly women
T2 - The women's health and aging study
AU - Rathouz, Paul J.
AU - Kasper, Judith D.
AU - Zeger, Scott L.
AU - Ferrucci, Luigi
AU - Bandeen-Roche, Karen
AU - Miglioretti, Diana L.
AU - Fried, Linda P.
PY - 1998/4/15
Y1 - 1998/4/15
N2 - 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.
AB - 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.
KW - Activities of daily living
KW - Aged
KW - Aging
KW - Disability evaluation
KW - Epidemiologic methods
KW - Questionnaires
KW - Women
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UR - http://www.scopus.com/inward/citedby.url?scp=0032522408&partnerID=8YFLogxK
U2 - 10.1093/oxfordjournals.aje.a009521
DO - 10.1093/oxfordjournals.aje.a009521
M3 - Article
C2 - 9554418
AN - SCOPUS:0032522408
SN - 0002-9262
VL - 147
SP - 764
EP - 773
JO - American journal of epidemiology
JF - American journal of epidemiology
IS - 8
ER -