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Majority of clinicians overestimate harms, benefits of treatment

Most resident and attending internal medicine physicians overestimated both the benefits and harms of common medical tests and treatments, according to findings published in JAMA Internal Medicine.

These included the prevention of myocardial infarction or stroke with daily aspirin, frequency of biopsy among patients receiving screening mammograms, prevention of hip fracture in patients with osteoporosis using alendronate and prevention of mortality in patients with acute peptic ulcer bleeding using proton pump inhibitors, Mona Krouss, MD, from the University of Maryland Medical Center, and colleagues reported.

"Effective patient care requires not only a working knowledge of recommended tests and therapies but also an understanding of the frequency of harms and benefits for each," the researchers wrote. "To make educated decisions, patients must understand harms and benefits of treatments. Unfortunately, patients consistently overestimate benefits and underestimate harms of medical tests and procedures. Likewise, physicians are poor at assessing treatment effect size and other aspects of numeracy."

Krouss and colleagues analyzed 117 survey responses which assessed attending physician and resident comprehension of the harms and benefits of various medical interventions, confidence, statistical terms and high-value care campaigns.

Results showed that 92 physicians (78.6%) overestimated benefit and 77 physicians (65.8%) overestimated harms. The researchers also reported that 53 respondents (67.5%) indicated that they were not confident by choosing four or less on a scale of one to 10.

"Our study results add to previous studies demonstrating patients overestimated benefits and underestimated harms," Krouss and colleagues concluded. "Physicians underestimate how often most treatments have no effects on patients — either harmful or beneficial. These physician beliefs likely contribute to the same misconceptions patients have for the benefits of treatments and may lead to medical overuse. Even when clinicians understand numeracy, expressing these terms in a way patients will understand is challenging. Development of more readily accessible decision-making aids may improve both clinician and patient understanding."

They also noted that attending physicians were more cognizant of high-value care campaigns, but there was no difference in accuracy between attending physicians and residents. Krouss and colleagues suggested using treatment effect size, absolute risk reduction or number needed to treat which are more precise than just P values, despite current focuses of medical education.

In an accompanying editorial, Anna L. Parks, MD, from the University of California, San Francisco, and Patrick G. O'Malley, MD, MPH, from the Uniformed Service University of the Health Sciences, wrote that the findings indicate a need for additional training.

"Most primary care physicians incorrectly interpret cancer screening statistics, believing that a screening test that improves detection rates or 5-year survival saves lives," they wrote. "Additional studies have suggested that physicians lack skill in explaining the benefits and harms of mammography and oral contraceptive pills, as well as cardiovascular risk."

Parks and O'Malley cited a recent study that summarized evidence-based risk communication strategies for physicians.

"These authors recommended that clinicians should avoid qualitative descriptions like 'high risk' and the difficult-to-understand 'number needed to treat' and instead quote actual event rates and natural frequencies," they wrote. "In addition, they recommended that physicians should discuss absolute risk increase or reduction rather than relative values, which may inflate the perception of the effects of various interventions. The addition of a visual representation of probabilities using bar graphs or icon arrays similarly increases patient understanding and satisfaction. Comprehension is also improved when probabilities are placed into context by using comparative risks and benefits." – by Chelsea Frajerman Pardes

Disclosures: Morgan has received editorial honoraria from Springer for serving as a book and journal editor. No other authors reported any relevant financial disclosures.