Perceived risk of developing breast cancer: how we phrase the question determines the answer.

This study assesses how the measurement of risk perceptions regarding breast cancer can influence the accuracy of perceived risk. Women from the general population (N = 580) completed estimates of absolute risk of breast cancer in numerical terms (0 to 100%) and verbal descriptors (very low to very high). Comparative risk was assessed by asking women to rate their risk compared to an average woman (much lower to much higher). Objective medical risk was computed from medical information regarding family history of breast cancer, age of menarche, number of children, age and ethnicity using the Gail Model (Gail et al., 1989). A series of ANOVAs indicate that, relative to Gail scores, women hold a strong pessimistic bias regarding risk of developing breast cancer when risk is measured numerically. Women estimated their risk as much higher than their objective medical risk. In contrast, a strong optimistic bias is evident in comparative risk estimates, whilst perceptions of risk are more accurate when rated on verbal descriptors. These findings have implications for the type of measurement used; results may simply reflect measurement differences rather than variations in perceived risk. Researchers need to take these disparities into account when choosing which method to use.