Two researchers in Australia conducted a systematic review of 48 studies to determine if clinicians have accurate expectations of the benefits and harms of treatments, imaging, and screening.
Twenty of the 48 studies focused on treatment, 20 on medical imaging, and 8 on screening. Of the 48 studies, 30 (67%) assessed only harm expectations, 9 (20%) evaluated only benefit expectations, and 6 (13%) assessed both benefit and harm expectations.
Among the studies comparing benefit expectations with a correct answer to questions covering 28 possible benefit outcomes, most participants provided a correct estimation for only 3 outcomes (11%). Of the studies comparing expectations of harm with a correct answer to questions on 69 possible harmful outcomes, a majority of participants correctly estimated harm for only 9 outcomes (13%). Where overestimation or underestimation data were provided, most participants overestimated benefit for 7 (32%) and underestimated benefit for 2 (9%) of the 22 outcomes, and underestimated harm for 20 (34%) and overestimated harm for 3 (5%) of the 58 outcomes.
Thus, clinicians, rarely had accurate expectations of benefits or harms, with inaccuracies in both directions. However, clinicians more often underestimated rather than overestimated harms and overestimated rather than underestimated benefits. The researchers concluded that inaccurate perceptions about the benefits and harms of interventions are likely to result in suboptimal clinical management choices. The study findings are available here.