Medical reversal

Medical reversal refers to when a newer and methodologically superior clinical trial produces results that contradict existing clinical practice and the older trials on which it is based. This leads to an intervention that was widely used falling out of favor, because new evidence either demonstrates that it is ineffective or that its harms exceed its benefits. It is distinct from replacement, which occurs when a newly developed medical treatment supersedes an older, less effective one as the standard of care.[1] Medical reversals are caused when a treatment is widely adopted even when there is not compelling evidence for its safety and effectiveness. For example, an intervention may be adopted because it "makes sense", or because there are observational studies supporting its putative benefits.[2] Notable examples of medical reversals include hormone therapy, class 1C antiarrhythmic agents, and pulmonary artery catheters, all of which became less commonly used after trials found them to be either harmful or less effective than previously believed. The negative effects of such reversals include harm to patients who received the intervention when it was considered relatively safe and effective, as well as reducing public trust in medicine.[3] The term evidence reversal has also been proposed to refer to the same concept as medical reversal, but with a broader scope, including other scientific disciplines in addition to medical science.[4]

The tomato effect is a parallel concern. But, instead of clinical trials producing a different result, it is about changes in theory or the current understanding of a disease.