Measuring risk perception among low-income minority primary care patients.

Studying patients' risk perceptions by ascertaining the probabilities of developing a disease is suboptimal, as patients might have difficulty using numerical expressions to depict the probabilities/chances of developing a disease. We surveyed patients at 2 community health centers and assessed risk perception by patients' self-reported chance of developing a disease (expressed in percentages), patients' relative chance of developing a disease compared to others' chance of developing a disease, and patients' ranked chances of developing different diseases. Many patients had difficulties understanding percentages and most patients overestimated their absolute risk. However, most patients indicated that they had a lower chance of developing diseases when compared to others. Patients with known risk factors (smoking) indicated a higher relative risk of developing an associated disease (lung cancer). Patients' ranked chances of developing different diseases were consistent with the actual frequency of developing a disease. Although patients had difficulty expressing risk in percentages, they estimated their risks well through comparisons with others and by ranking of disease frequencies.