Short Communication Communicating Breast Cancer Risks to Women Using Different Formats 1 Isaac M. Lipkus, 2 William M. P. Klein, and Barbara K. Rimer Duke University Medical Center, Cancer Prevention, Detection, and Control Research Program, Risk Communication Laboratory, Durham, North Carolina 27701 [I. M. L.]; Colby College, Waterville, Maine 04901 [W. M. P. K.]; and The National Cancer Institute, Bethesda, Maryland 20892 [B. K. R.] Abstract Using a pre-post test design with a baseline, laboratory, and a 6-month follow-up, we communicated women’s objective breast cancer risks, based on the Gail Model, using two formats: (a) range of risks (e.g., risk of breast cancer can be as low as 1% and as high as 5%); and (b) as a point estimate (e.g., your risk of breast cancer is 3%). We examined how these presentations individually and jointly affected women’s perceived lifetime breast cancer risks. Overall, providing risk estimates either as a range of risks or as a point estimate lowered women’s perceived lifetime risks compared with women who did not get information presented this way shortly after receipt of this information relative to baseline. At the 6- month follow-up, perceptions of lifetime risks generally returned to their baseline values. Overall, women viewed their risk feedback, whether presented as a point estimate or as a range of risks, as equally credible, trustworthy, accurate, and personally relevant. These results suggest that women evaluate risk feedback containing either point estimates or range of risks as equally acceptable. Both formats lead to short-term reductions in perceived risk (i.e., greater accuracy). Introduction Breast cancer is one of the few diseases that has quantitative models, such as the Gail Model (1), to predict women’s risk. Women typically overestimate their breast cancer risks (2– 4). How can breast cancer risk be communicated to increase wom- en’s accuracy of their perceived risks? Absolute risk can be communicated as a point estimate (e.g., your risk is 3%), as a range (e.g., your risk can be as low as 1% and as high as 5%), and as a point estimate plus range. We report how women’s perceived breast cancer risks were affected by these presenta- tional variations. Reactions Toward Information about Personal Breast Cancer Risk. According to Prospect Theory (5), people eval- uate information based on a modifiable reference point. Out- comes above and below the reference point can be viewed as gains (benefits) and losses (costs), respectively (6). If a wom- an’s subjective risk of getting breast cancer serves as one reference point, outcomes below this point, representing less risk, should be viewed as a gain; outcomes above this point, representing greater risk, should be viewed as a loss (e.g., a woman who believes her lifetime risk is 20% and is told her risk is 3% should interpret this information as a gain). The interpretation of risk feedback as a gain or loss should interact with presentation format. People generally prefer pre- cision to lack of precision or uncertainty, especially when precise information conveys good news (7, 8). Unlike a range of risks, a point estimate reflects greater precision and should be preferred, especially for women informed their risk is below their subjective risk estimates (gain). That is, obtaining precise information that their risk is lower than expected should be strongly accepted. Conversely, women informed their risks are higher than their subjective risk estimates (loss) should prefer a range of risks, because a range can represent vagueness (i.e., less precision; Refs. 9 and 10). Vague probabilities may imply that the true probabilities can be better or worse. For women who view their breast cancer risk feedback as conveying a loss, a range of risk values offers the hope that their actual risk may be at the lower end of the range (i.e., risk is not as bad as it seems; Ref. 10). Perceived Breast Cancer Risks as a Function of Combining a Point Estimate with Range of Risks. How should a woman view her risks when presented with a point estimate and a range of risks? We hypothesize that when people are presented with a range of risks, they try to gather and/or use information to improve precision. Because of people’s propensity to see them- selves at lower than at higher risk (11, 12), they will tend to place themselves at the lower end of the continuum, represent- ing less risk. A point estimate provides an anchor to solidify the location of risk (13). When a point estimate and a range of risks are given, a woman should view her risk somewhere in between the point estimate and the lower bound of risk. Hypotheses. We tested the following predictions. 3 H1. Providing any form of risk feedback (point estimate or range of risks) will lower women’s perceived risks more than not providing any risk feedback. H2. Women who get a point estimate plus a range of risks will report the lowest perceived risks pre-post compared with women who only get a point estimate, a range, or no risk feedback. Received 9/15/00; revised 5/25/01; accepted 6/1/01. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. 1 Supported by The National Cancer Institute Grant CA72099-05. 2 To whom requests for reprints should be addressed, at 905 West Main Street, Box 34, Durham, NC 27713. Phone: (919) 956-5253; Fax: (919) 956-7451; E-mail: lipku001@mc.duke.edu. 3 Because the majority of women in our study overestimated their breast cancer risks, we did not have sufficient power to detect if those who overestimated and underestimated their risks had differential responses to risk feedback information. 895 Vol. 10, 895– 898, August 2001 Cancer Epidemiology, Biomarkers & Prevention on January 13, 2022. © 2001 American Association for Cancer Research. cebp.aacrjournals.org Downloaded from