Importance: For stable angina, the benefits of percutaneous coronary intervention (PCI) are limited to symptom relief, but patients often believe that PCI prevents myocardial infarction (MI). Whether presenting accurate information about the benefits of PCI would dispel these beliefs remains unknown. We hypothesized that explanatory information would be more effective for influencing volunteers' beliefs.
Objective: To assess the effect of explicit and explanatory information on participants' beliefs about PCI and their willingness to choose it.
Design, setting, and participants: We conducted a randomized trial in 2012 among adults older than 50 years living in the general community. We recruited participants using the Internet.
Interventions: Participants read 1 of 3 scenarios in which they experienced class I angina and were referred to a cardiologist. The cardiologist provided no information about the effects of PCI on MI risk, a specific statement that PCI does not reduce MI risk, or an explanation of why PCI does not reduce MI risk.
Main outcomes and measures: Participants' beliefs about the benefit of PCI and choice of PCI and medication.
Results: A total of 1257 participants (90.0%) completed the survey; 54.5% chose PCI. Compared with those receiving explicit and explanatory information, those receiving no information were most likely to believe that PCI prevents MI (71.0% vs 38.7% vs 30.6%, respectively; P < .001), most likely to choose PCI (69.4% vs 48.7% vs 45.7%, respectively; P < .001), and least likely to agree to medication therapy (83.1% vs 87.4% vs 92.3%, respectively; P < .001). Across the entire sample, the decision to have PCI was strongly correlated with the belief that PCI would prevent MI (odds ratio, 5.82 [95% CI, 4.13-8.26]) and that the participant would feel less worried (odds ratio, 5.36 [95% CI, 3.87-7.45]), but was not associated with how much participants were limited by symptoms.
Conclusions and relevance: In the setting of mild, stable angina, most people assume PCI prevents MI and are likely to choose it. Explicit information can partially overcome that bias and influence decision making. Explanatory information was the most effective intervention in overcoming this bias.