"Medical reversal" is a term that defines instances in which new and improved clinical trials show that current medical practices are ineffective or misguided. New research reveals that there are currently almost 400 medical reversals.

Medical reversals occur when new clinical research shows that a certain medical practice does not, in fact, work or it does more harm than good. These new studies are superior to their predecessors because of things like better controls, better study design, or larger sample size. Medical reversals often concern medications, but they can also affect surgical procedures.

For instance, more than a decade ago, researchers and health-care professionals realized that stenting procedures did not work for renal artery stenosis and that routine stenting should not be used to treat stable coronary disease. Now, a new meta-analysis of 3,000 studies identifies almost 400 cases of medical reversals. The review appears in the journal eLife.

Diana Herrera-Perez, a research assistant at the Knight Cancer Institute at Oregon Health & Science University (OHSU), in Portland, is the lead author of the new analysis.

Analysis finds 396 medical reversals

Referring to well-known endeavors to assess the validity of clinical practices, such as the Cochrane reviews, Herrera-Perez says, "We wanted to build on these and other efforts to provide a larger and more comprehensive list for clinicians and researchers to guide practice as they care for patients more effectively and economically."

To do so, she and colleagues examined over 3,000 randomized, controlled trials published in three prestigious medical journals over the last 15 years: The Journal of the American Medical Association, The Lancet, and The New England Journal of Medicine.

The analysis revealed 396 medical reversals: 154 of them in JAMA, 129 in NEJM, and 113 in The Lancet. Researchers carried out most of these studies (92%) in high-income countries, while 8% were performed in low- or middle-income countries, including China, India, Malaysia, Ghana, Tanzania, and Ethiopia. Most of the medical reversals occurred in the fields of cardiovascular disease (20%), public health and preventive medicine (12%), and critical care (11%).

Specifically, the most common interventions involved medications (33%), procedures (20%), vitamins and supplements (13%), devices (9%), and system interventions (8%).

Main takeaways from the results

The study's senior author, Dr. Vinay Prasad, a hematologist-oncologist and associate professor at the OHSU Knight Cancer Institute, comments on the findings. "There are a number of lessons that we can take away from our set of results, including the importance of conducting [randomized controlled trials] for both novel and established practices," he says.

"Once an ineffective practice is established, it may be difficult to convince practitioners to abandon its use. By aiming to test novel treatments rigorously before they become widespread, we can reduce the number of reversals in practice and prevent unnecessary harm to patients."

—Dr. Vinay Prasad

He adds, "We hope our broad results may serve as a starting point for researchers, policymakers, and payers who wish to have a list of practices that likely offer no net benefit to use in future work."

Dr. Prasad cautions that the review has some limitations, such as the small number of journals it includes and the limited expertise of the reviewers.

To overcome such limitations, co-lead study author Alyson Haslam, PhD, who is also affiliated with the OHSU Knight Cancer Institute, calls for experts from various fields to critically assess the medical reversals identified in the analysis.

She says, "Taken together, we hope our findings will help push medical professionals to evaluate their own practices critically and demand high-quality research before adopting a new practice in [the] future, especially for those that are more expensive and/or aggressive than the current standard of care."