Objective: Patients undergoing coronary artery bypass graft (CABG) surgery are required to take a complex regimen of medications for a long time, and they may have negative outcomes because they struggle to adhere to this regimen. Designing effective interventions to promote medication adherence is therefore important. The present study aimed to evaluate the long-term effects of a multifaceted intervention (psycho-education, motivational interviewing, and short message services) on medication adherence, quality of life (QoL), and mortality rates in older patients undergoing CABG surgery.

Methods: Patients aged over 65 years from 12 centers were assigned to the intervention (EXP; n = 144) or treatment as usual (TAU; n = 144) groups using cluster randomization with center level. Medication adherence was evaluated using Medication Adherence Rating Scale (MARS), pharmacy refill rate, and lipid profile; QoL using Short-Form 36.Data were collected at baseline; three, six, and eighteen months after intervention. Survival status was followed up at eighteen months. Multi-level regressions and survival analyses for hazard ratio (HR) were used for analyses.

Results: Compared to patients who received TAU, the MARS, pharmacy refill rate, and lipid profile of patients in the EXP group improved six months after surgery (p <0.01) and remained so eighteen months after surgery (p< 0.01). QoL also increased among patients in the EXP group as compared to those who received TAU at eighteen month post-surgery (physical component summary score p= 0.02; mental component summary score p = 0.04). HR in the EXP group compared to the TAU group was 0.38 (p = 0.04).

Conclusion: The findings suggest that a multifaceted intervention can improve medication adherence in older patients undergoing CABG surgery, with these improvements being maintained after eighteen months. QoL and survival rates increased as a function of better medication adherence.