Using the SF-36 with older adults: a cross-sectional community-based survey

Abstract

OBJECTIVES: To assess the practicality and validity of using the SF-36 in a community-dwelling population over 65 years old, and obtain population scores in this age group. DESIGN: Postal survey, using a questionnaire booklet containing the SF-36 and other health related items, of all those aged 65 or over registered with twelve general practices. Non-respondents received up to two reminders at three-weekly intervals. SETTING: Twelve randomly selected general practices in Sheffield. SAMPLE: 9897 subjects aged 65 to 104. MAIN OUTCOME MEASURES: Scores for the eight dimensions of the SF-36 and a modified version of the physical functioning dimension. RESULTS: The SF-36 achieved a response rate of 82% (n=8117) and dimension completion rates of 86.4% to 97.7%. Internal consistency measured by Cronbach’s a exceeded 0.80 for all dimensions except social functioning. These results compare favourably with postal surveys of younger adults. Scores for older adults were calculated by age and sex. Comparison with data from younger people showed how physical health declines steeply with age, in marked contrast with mental health. CONCLUSIONS: The SF-36 is a practical and valid instrument to use in postal surveys of older people living in the community. The population scores provided here may facilitate its use in future surveys of older adults