OBJECTIVES : Lipid lowering therapy (LLT) up-titration aims to increase the potency of treatment received by the patient thereby augmenting LDL-C reduction. However, the impact of LLT modifications on medication adherence is not clear. The objective of this study was to identify the impact of treatment modification including up-titration, down titration or switching, on medication adherence in older adults on LLT

METHODS : A retrospective cohort study was conducted in adults ≥ 65 years and continuously enrolled in a Medicare Advantage Plan for two years after their first LLT use between January 2016 and May 2018. Patients were categorized into 3 groups based on their medication utilization pattern in the first year as: (a) patients with up-titration (UpT) (b) patients with no treatment changes (NoC) (c) patients with other treatment changes (OthC). Adherence was measured as proportion of days covered (PDC) with a value between 0-1 for each month. Piecewise regression with repeated value of monthly PDC as the outcome was used to evaluate the change in monthly adherence for one year prior and one year post the regimen modification.

RESULTS : Of the 10,038 patients, all the groups had a decrease in mean monthly PDC in the year prior to treatment modification, with the highest decrease of 1.4% for NoC followed by 1.1% for UpT and 0.9% for OthC groups. The PDC significantly improved after the treatment modification in all groups. The mean PDC increase after the treatment modification was 0.3% in the NoC, 1% in the UpT group and 1.9% in the OthC group. PDC change was significantly different between the OthC and NoC group, but not significant between the UpT and NoC group.

CONCLUSIONS : Switching and down-titration were associated with the greater improvement in adherence compared to up-titration. Regular monitoring could prevent the decline in adherence to chronic medications which is observed over time.