PDB121 EVALUATING INTERVENTION TRAJECTORIES OF STATIN ADHERENCE FOLLOWING A MOTIVATIONAL-INTERVIEWING INTERVENTION CUSTOMIZED BY PAST ADHERENCE TRAJECTORIES TO IMPROVE STATIN ADHERENCE

Abstract

Group-based trajectory modeling depicts longitudinal adherence over time, overcoming some limitations of proportion of days covered (PDC). Adherence to statins remains sub-optimal despite its effectiveness in improving cardiovascular outcomes. A telephonic Motivational Interviewing Intervention (MoI) was conducted by trained pharmacy students to improve statin adherence in a Medicare Advantage Plan. Four adherence trajectories were identified in the one-year pre-intervention period including: rapid decline (RD), gradual decline (GD), gaps in adherence (GA) and adherent. These trajectories were used to customize the MoI intervention. The objective was to evaluate post-intervention adherence trajectories as compared to pre-intervention trajectories for those receiving the MoI. Patients from the 3 non-adherent pre-intervention trajectories were randomized to control or intervention. Patients who received the intervention and randomly selected controls were followed for six months from the date of the initial counseling. Monthly PDCs were calculated during the 6-month follow-up and dichotomized with PDC ≥ 0.8 considered as adherent. Logistic group-based trajectory modeling on PDC was performed on the intervention and controls to identify three relevant post-intervention trajectories. Descriptive statistics were performed to assess differences in pre and post-intervention adherence trajectories. There were 151 intervention patients and 310 randomly selected controls. Post-intervention trajectories identified were, (1) GD (24.3%) (2) adherent (58.3%) and (3) discontinuation (17.57%) respectively. More patients in the intervention group as compared to the control group were in the adherent trajectory post-intervention (66.89% vs 53.87%) (p= 0.007). Similarly, fewer discontinuations were observed with the intervention group (11.92% vs 20.32%) (p= 0.02). Further, more patients in the GA pre-intervention trajectory (75.6% intervention, 68.9% controls) moved to the adherent trajectory post-intervention indicating greater benefits of intervention to this patient subgroup. The post-intervention adherence trajectory patterns were simpler than the pre-intervention trajectory patterns with many patients moving into an adherent trajectory especially among those receiving the intervention.