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

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.

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.

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 (P=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.

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.

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).