Methodology of therapeutic trials: lessons from the late evidence of the cardiovascular toxicity of some coxibs◊

The removal of rofecoxib after several years on the market has caused deep concern among patients, physicians, researchers, editors, and regulatory agencies. Similar situations have occurred in the recent past. They illustrate the serious limitations of preregistration trials. Approved drugs should be subjected to close postmarketing surveillance. A number of methodological issues regarding the evaluation of drug safety are discussed in this article. The advantages and drawbacks of observational studies and randomized trials are reviewed. Emphasis is put on the usefulness of independent steering committees for therapeutic trials and on the value of cumulative meta-analyses.