The Optimizing-Risk-Communication (OptRisk) randomized trial - impact of decision-aid-based consultation on adherence and perception of cardiovascular risk.

Background: Shared decision-making is a well-established approach to increasing patient participation in medical decisions. Increasingly, using lifetime-risk or time-to-event (TTE) formats has been suggested, as these might have advantages in comparison with a 10-year risk prognosis, particularly for younger patients, whose lifetime risk for some events may be considerably greater than their 10-year risk. In this study, a randomized trial, the most popular 10-year risk illustration in the decision-aid software Arriba (emoticons), is compared with a newly developed TTE illustration, which is based on a Markov model. The study compares the effect of these two methods of presenting cardiovascular risk to patients on their subsequent adherence to intervention.

Methods: A total of 294 patients were interviewed 3 months after they had had a consultation with their GP on cardiovascular risk prevention. Adherence to behavioral change or medication intervention was measured as the primary outcome. The latter was expressed as a generated score. Furthermore, different secondary outcomes were measured, ie, patient perception of risk and self-rated importance of avoiding a cardiovascular event, as well as patient numeracy, which was used as a proxy for patient health literacy.

Results: Overall, no significant difference in patient adherence was found depending on risk representation. In the emoticon group, the number of interventions had a significant impact on the adherence score (=0.025). Perception of risk was significantly higher in patients counseled with the TTE risk display, whereas the importance of avoiding a cardiovascular event was rated equally highly in both groups and actually increased over time.

Conclusion: The TTE format is an appropriate means for counseling patients. Adherence is a very complex construct, which cannot be fully explained by our findings. The study results support our call for considering TTE illustrations as a valuable alternative to current decision-support tools covering cardiovascular prevention. Nevertheless, further research is needed to shed light on patient motivation and adherence with regard to cardiovascular risk prevention.

Trial Registration: The study was registered at the German Clinical Trials Register and at the WHO International Clinical Trials Register Platform (ICTRP, ID DRKS00004933); registered February 2, 2016 (retrospectively registered).