title: Comparison of two physical activity questionnaires, with a diary, for assessing physical activity in an elderly population.
abstract: Measurement of physical activity in epidemiological studies is usually achieved by means of a questionnaire. Little work has been done to determine which questionnaire format has greater validity in an elderly population. In this study of elderly subjects, physical activity as reported in two self-administered questionnaires (A and B), which differed in format and length, were compared to activity reported in a 4 day diary. As compared with the diary, moderate/heavy activity was more accurately reported in Questionnaire A (mean difference 5 min), the longer more detailed questionnaire, than B (mean difference 170 min). Light activity was under reported in Questionnaire A (mean difference 68 min) and over reported in B (mean difference 88 min) as compared with the diary. In contrast, time spent sitting was more accurately reported in Questionnaire B (mean difference 40 min) than in A (mean difference 230 min) as compared with the diary. The longer more detailed questionnaire was the more accurate instrument for assessing moderate/heavy activity in this elderly population. The shorter questionnaire was more accurate for assessing time spent sitting.
authors.affiliation: Arizona Cancer Center, Tucson 85724.
authors.forename: B
authors.initials: B
authors.lastname: Cartmel
authors.forename: T E
authors.initials: TE
authors.lastname: Moon
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D003625:Data Collection / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires