Evaluating the efficacy of medical treatment: possibilities and limitations.

This review outlines the possible uses of subjective health status measures in the evaluation of medical treatment, and possible limitations and pitfalls that potential users of such measures must be aware. Whilst much has been written about the requirements of measures in terms of reliability, validity and responsiveness, many existing measures which have gained widespread use have serious shortcomings. In this paper, the limitations of some existing questionnaires are outlined. It is argued that whilst outcomes measurement has the promise to positively influence medical care, done without due consideration of its limitations and weaknesses it could lead to inaccurate or inappropriate data. In the current climate, in which health outcomes data is viewed as central to monitoring and evaluation, inappropriate or unconsidered use of measures could have drastic effects.