Critical appraisal of clinical trials in oncology — part I

Abstract

The main concept of evidence-based medicine is that all therapeutic decisions should be based on results from relevant, credible, and up-to-date clinical trials. Availability of a publication presenting a description of a clinical trial conducted with reliable methods and its high-quality results seems to be an ideal situation from the practitioner’s point of view. However, reading only the abstract or just the author’s conclusions may not always be sufficient to make the right clinical decision. For this purpose, several aspects of the clinical trial should be put under assessment, namely the methodology, its quality, internal and external credibility, clinical and statistical significance, as well as consistency of the results. The ability to perform the proper assessment of clinical trials may prove to be very helpful for practicing oncologists, especially in the case of new, emerging therapies, specific clinical situations, or when salvage treatment is necessary. It is also worth emphasising that the outcome assessment in oncology trials is specific, mainly due to the role of the survival analysis, which is relatively difficult to interpret. In this paper we tried to present in a clear and intelligible way the theoretical basis and subsequent steps in the critical appraisal of methods and results of clinical trials in oncology.