Most people overestimate benefits of medical treatment

Patients often overestimate the benefits of medical treatment and underestimate the dangers, often resulting in them getting more treatment than they may need. This was the conclusion of a study, published in JAMA Internal Medicine, which was the first to systemically review the literature reflecting patients’ expectations about medical treatment.

More than 30 studies were evaluated, and the results suggested that patients’ views were often skewed. For instance, of 34 studies analyzed, patients overestimated the benefits of their medical treatment in 22, or 65 percent, of them.

For example, one study on breast cancer patients showed 80 percent of women who underwent a double mastectomy thought they reduced their cancer risk from 76 to 11 percent, when in actuality their risk before surgery was only 17 percent.

Another study showed 80 percent of patients overestimated the benefits of medications to prevent hip fractures; 90 percent overestimated the benefits of breast cancer screening; and 94 percent overestimated the benefits of bowel cancer screening.

In the 15 studies that focused on harmful outcomes, patients underestimated the level of harm in 10 of them. For example, one study showed 40 percent of people underestimated the risks of radiation exposure when receiving CT scans. Meanwhile, 60 percent underestimated the risk of developing cancer from CT scans.

Why were expectations so off? One assumption is the information patients receive from their doctor, pharmaceutical ads and the media are skewed to focus on the benefits. This study suggests that if patients had more and better information, they would opt for less care than they currently receive.

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Sourced from:, If Patients Only Knew How Often Treatments Could Harm Them