Background: Chemoprevention plays a major role in risk modification for breast cancer. However, the uptake of chemoprevention among women who qualify for prophylaxis remains suboptimal.
Objective: The purpose of this study was to understand the effect of decision aid’s message format (graphic vs. written) on the risk appraisal and the intention to start chemoprevention.
Methods: In this field experiment, adult, English-speaking women in the city of Houston were recruited from public settings using convenient sampling approach. Each participant was exposed to two decision aid message formats, alternatively, providing graphic and written information regarding risks and benefits associated with the chemoprevention drugs. Following the theoretical frameworks of the Rohrmann’s risk model and the health belief model, we assessed the constructs of risk appraisal and the intent to use chemoprevention, using a pre-validated questionnaire. The survey data were collected before and after the decision aid intervention. The responses to risk appraisal and intention measures were recorded on a Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree). The difference in mean scores between the graphic and written formats were tested using ANOVA and paired t-tests. Path analysis was performed to assess the direct and indirect effects of message format on the intention.
Results: A total of 320 women participated with a response rate of 81.4%. The mean (SD) age of the women was 40 (11.27) years. Over a quarter of women (27%) had a family history of breast cancer, 12% had a personal history of breast biopsy, and 28% had heard of chemoprevention before. Mean scores for message format for each construct of the theoretical model were as follows: perceived susceptibility (graphic: 3.00, written 2.88, P=0.04), perceived severity (graphic: 2.97, written: 2.98, P=0.8), perceived benefit (graphic: 3.05, written: 3.04, P=0.9), perceived adverse events (graphic: 2.78, written: 2.76, P=0.7), intention to use chemoprevention (graphic: 3.35, written: 3.47, P=0.11). Path analysis showed that perceived susceptibility played a mediating role between message format and risk appraisal, while a significant direct effect existed between message format and the intention (beta = 0.057; p < 0.05).
Conclusions: There was a direct and indirect effect of message format on intention to start chemoprevention and the constructs of risk appraisal play an important mediating role. Decision aid’s message format should be taken into consideration in designing interventions to improve uptake of chemoprevention.
