Impact of Timing and Format of Patient Decision Aids on Involvement in Shared Decision-Making for Patients With Breast Cancer: The IMPACTT Randomized, Controlled Study

BACKGROUND: For people with breast cancer facing adjuvant treatment decisions, it is unclear whether providing a patient decision aid (PtDA) before versus during the consultation leads to greater involvement in shared decision-making (SDM). The overall aim was to evaluate the effect of a digital preconsult PtDA compared with an identical in-consult paper-based PtDA. PATIENTS AND METHODS: In this randomized controlled trial, patients with breast cancer eligible for adjuvant treatment were randomized to a digital PtDA before consultation or a paper-based PtDA during consultation. Primary outcome was patient-reported SDM Process_4. Secondary outcomes included observer-rated SDM (OPTION5/12), patient- and physician-reported SDM-Q, decisional conflict, CollaboRATE, preparation for decision-making, and consultation duration. Between-group differences were estimated using linear regression; post-consultation outcomes were analyzed with standard errors clustered at the physician level. RESULTS: A total of 204 patients were randomized. Mean SDM Process_4 score was lower in the preconsult group, but not significant (P = .154). Observer-rated SDM was significantly higher in the in-consult group (OPTION5; P = .019; OPTION12: P = .005). The preconsult group reported lower decisional conflict before the consultation (P = .002) and lower preparation for decision-making (P = .004). No significant between-group differences were observed for post-consultation decisional conflict, SDM-Q, CollaboRATE, or consultation duration. CONCLUSIONS: Patient-reported SDM did not differ significantly between groups, but the paper-based in-consult PtDA was associated with higher observer-rated SDM. Digital PtDAs may reduce decisional conflict before consultation, but structured integration into the encounter may be needed to support observable SDM.