Validation of the Short Form 36 (SF-36) health survey questionnaire among stroke patients

Abstract

Background and purpose: Few studies have examined the utility of a new generic health status measure, the Short Form 36 health survey questionnaire (SF-36), in stroke patients. Our aim was to test the internal consistency and validity of the SF-36 in a cohort of long-term stroke survivors.

Methods: The Australian version of the SF-36 was tested in 90 consecutive 1-year stroke survivors (mean age, 72 years) identified from our hospital discharge data. The instrument was administered by personal interview. Validity was assessed by comparing patients' scores on the SF-36 with those obtained for the Barthel Index, the 28-item General Health Questionnaire, and the Adelaide Activities Profile, an instrument developed from the Frenchay Activities Index.

Results: The SF-36 was relatively quick and easy to use and had satisfactory internal consistency (Cronbach's alpha > 0.7). For all eight SF-36 health scales, the mean scores for patients dependent in self care and with mental ill health were significantly different from patients without these disabilities, but the strength of the differences varied in a predictable manner. However, the SF-36 social functioning scale did not provide a valid measure of everyday activities relevant to many elderly patients as measured by the Adelaide Activities Profile.

Conclusions: The SF-36 avoids the "ceiling effect" of most disability scales and provides a valid measure of physical and mental health after stroke, but it does not appear to characterize well social functioning. Thus, the instrument may need to be supplemented by other measures for a comprehensive assessment of stroke outcome.