The art of quality assessment of RCTs included in systematic reviews

Abstract

The best evidence on the efficacy of medical interventions is provided by high-quality trials summarized in high-quality systematic reviews or meta-analyses. The methodological quality of studies included in a systematic review can have a substantial impact on the estimates of the treatment effect and therefore on the conclusions of such a review. But what is the empirical evidence to support quality assessment of randomized clinical trials (RCTs)? We elaborate on questions such as: what is the concept of quality of individual studies (RCTs), can quality be measured validly and reliably? Plans for future research on this issue are proposed.