Reliability, Validity, and Application of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) in Schizophrenic Patients Treated With Olanzapine Versus Haloperidol

Abstract

Schizophrenia leads to impairments in mental, social, and physical functioning, which should be included in evaluations of treatment. This study was designed to determine the reliability and validity of the Medical Outcomes Study Short Form Health Survey (SF-36) for schizophrenic patients, to characterize perceived functioning and well being and to compare short-term change in SF-36 scores for patients treated with olanzapine or haloperidol. Data were obtained from a randomized, double-blind trial comparing these agents for safety, efficacy, and cost effectiveness. A 6-week acute treatment portion preceded a 46-week "responder extension" phase. A subsample (n = 1,155) completing a pre-treatment SF-36 provided data for this study. Psychometric analyses were conducted, and perceived level of functioning was compared with that for the US adult population. Change from baseline to 6 weeks was examined by treatment group. Clear evidence was obtained for the instrument's reliability and validity for these patients. There were marked deficits in General health, Vitality, Mental health, Social functioning, and in Role limitations resulting from both physical and emotional problems. Olanzapine-treated patients improved in 5 of 8 domains to a significantly greater degree than did haloperidol patients. The SF-36 can be a reliable and valid measure of perceived functioning and well being for schizophrenic patients. The perceptions of functioning can be valuable indices of disease burden and can help to demonstrate the effectiveness of newer anti-psychotic medications such as olanzapine.