Outcome assessment in clinical trials. Evidence for the sensitivity of a health status measure

Abstract

Health status measures are conceptually relevant to the assessment of clinical outcome in the rheumatic diseases, but their ability to detect meaningful changes in health has not been clearly demonstrated. This report describes the performance of a self-administered health status questionnaire in a randomized, double-blind, 21-week comparison of placebo, oral gold, and injectable gold in rheumatoid arthritis patients. Outcome was assessed by standard clinical measures, including joint count, grip strength, and laboratory tests, and by the Arthritis Impact Measurement Scales, a reliable and valid health status measure that assesses physical disability, psychological status, and pain. Data from the clinical and health status measures produced highly similar conclusions: injectable and oral gold are more effective than placebo for rheumatoid arthritis, and injections are slightly more effective than oral gold. The health status measure was thus quite sensitive to clinically meaningful drug-induced improvements. These findings provide justification for the further application of health status measures to clinical trials of chronic disease.