Background: Improving the quality of information and communication is a priority in organised breast cancer screening and an ethical duty. Programmes must offer the information each woman is looking for, promoting informed decision-making. This study aimed to develop and evaluate a web-based dynamic decision aid (DA).
Methods: A pragmatic randomised trial carried out in six regional organised screening programmes recruited women at the first invitation receiving DA or a web-based standard brochure (SB). The primary outcome was informed choice measured on knowledge, attitudes, and intentions. Follow-up period: 7-10 days. Secondary outcomes included participation rate, satisfaction, decisional conflict, and acceptability of DA.
Results: Two thousand one hundred and nineteen women were randomised and 1001 completed the study. Respectively, 43.9% and 36.9% in the DA and SB reached the informed choice. The DA gave a 13-point higher proportion of women aware about overdiagnosis compared to SB (38.3% versus 25.2%, p < 0.0001). The percentage of women attending screening was the same: 84% versus 83%. Decisional conflict was significantly lower in the DA group (14.4%) than in the SB group (19.3%).
Conclusion: DA increases informed choice. Complete information including the pros, cons, controversies, and overdiagnosis-overtreatment issues boost a woman's knowledge without reducing the rate of actual screening participation.
Clinical trial registration: ClinicalTrials.gov number NCT03097653.