Medical reversal occurs when a new clinical trial - superior to predecessors by virtue of better controls, design, size, or endpoints - contradicts current clinical practice. In recent years, we have witnessed several instances of medical reversal. Famous examples include the class 1C anti-arrhythmics post-myocardial infarction (contradicted by the CAST trial) or routine stenting for stable coronary disease (contradicted by the COURAGE trial). In this paper, we explore the phenomenon of medical reversal. The causes and consequences are discussed. Conflicts of interest among researchers and an unyielding faith in basic science are explored as root causes of reversal. Reversal harms patients who undergo the contradicted therapy during the years it was in favor and those patients who undergo the therapy in the lag time before a change in medical practice. Most importantly, it creates a loss of faith in the medical system by physicians and patients. The solution to reversal is upfront, randomized clinical trials for new clinical practices and a systematic method to evaluate practices already in existence.
Keywords: basic science; contradicted findings; evidence-based medicine; medical reversal; observational studies; randomized controlled trials.