Women's Awareness of and Responses to Messages About Breast Cancer Overdiagnosis and Overtreatment: Results From a 2016 National Survey.

Background: Scientists, clinicians, and other experts aim to maximize the benefits of cancer screening while minimizing its harms. Chief among these harms are overdiagnosis and overtreatment. Although available data suggest that patient awareness of these harms is low, we know little about how patients respond to information about these phenomena.

Objectives: Using the case of breast cancer screening, this study assesses women's awareness of and reactions to statements about overdiagnosis and overtreatment.

Methods: We draw on data from a 2016 population-based survey of US women aged 35-55 years that oversampled women of lower socioeconomic position (those living at or below 100% of federal poverty level) (N=429).

Results: Results showed that women's awareness of overdiagnosis (16.5%) and overtreatment (18.0%) was low, and women under age 40 were least likely to have heard about overdiagnosis. Most women did not evaluate statements about these harms positively: <1 in 4 agreed with and found statements about overdiagnosis and overtreatment to be believable, and even fewer evaluated them as strong arguments to consider in their own mammography decision making. Women with a recent mammogram history were particularly unconvinced by overdiagnosis and overtreatment arguments.

Conclusions: A majority of women were unaware of 2 important harms of breast cancer screening: overdiagnosis and overtreatment. Most did not find statements about these harms to be believable and persuasive. Communication interventions, supported by evidence from health communication research, are necessary to improve patient understanding of screening's harms, promote informed decision making, and, in turn, ensure high-value care.