Continuity of care and changes in medication adherence among patients with newly diagnosed diabetes

Abstract

Objectives: Recent studies have revealed significant variation in medication adherence among patients with chronic conditions. Little is known about the effect of continuity of care (COC) on changes in medication adherence. This study aims to identify medication adherence trajectories among patients with newly diagnosed diabetes, as well as to examine the association of COC and medication adherence among various adherence trajectories.

Methods: This study utilized a longitudinal design with a 6-year follow-up, from 2002 to 2008, under a universal health insurance program in Taiwan. Subjects 18 years or older with type 2 diabetes that was newly diagnosed in 2002 were included in the study. The main outcome was medication adherence measured by medication possession ratio each year. Group-based trajectory models were used for analysis.

Results: Four medication adherence trajectories were identified: persistent adherence (39.9%), increasing adherence (27.5%), decreasing adherence (12.0%), and nonadherence (20.6%). Patients with high or medium COC index scores were more likely to be adherent to medications than those with low COC index scores in all of the trajectory adherence groups.

Conclusions: This study demonstrated the heterogeneity in patients' medication adherence and identified 4 distinct trajectories of medication adherences among those with newly diagnosed type 2 diabetes. Improving COC may lead to better medication adherence in all of the adherence trajectory groups.