The SF-36 health survey: a valid measure of changes in health status after injury.
OBJECTIVES: The aim of this study is to evaluate the criterion validity and responsiveness to changes over time of the Medical Outcome Study Short Form 36 (MOS SF-36) measure. METHODS: A consecutive sample of 775 patients 16 to 78 years treated for an unintentional injury at the hospital or emergency clinic in Drammen, Norway was selected for the study. Data about activity restrictions and health status measured by SF-36 were obtained by a postal questionnaire 6-10 weeks after the injury. A follow up survey was sent 24-28 weeks later to all who reported activity restriction at the time of the first survey. Fifty two of these replied (63%). RESULTS: 469 patients responded to the survey questionnaire and of these, 82 experienced some restriction of activity. These scored lower (p < 0.01) on all eight SF-36 health dimensions (physical functioning, social functioning, role limitation (physical), role limitation (emotional), bodily pain, mental health, vitality, and general health) than the 387 patients without activity restriction. Scores on physical functioning, social functioning, role limitation (physical), bodily pain, and vitality significant improved (p < 0.01) among the 52 patients who were followed up. Scores on the other dimensions, however, showed no significant changes over time. CONCLUSION: The MOS SF-36 appears to be a valid instrument, responsive to changes in health status over time among unintentionally injured adult people. Thus it may be possible to use the SF-36 to describe changes in health due to injury. The applicability of this or similar measures for injured children remains to be established.