Comparison of medication persistence and adherence in type 2 diabetes using a once-weekly regimen of DPP-4 inhibitor compared with once-daily and twice-daily regimens: a retrospective cohort study of Japanese health insurance claims data

AimsAssess medication persistence and adherence for dipeptidyl peptidase-4 inhibitors (DPP-4i) administered once weekly (QW), once daily (QD), and twice daily (BID) among patients with type 2 diabetes (T2D), and explore factors associated with discontinuation and non-adherence for DPP-4i regimens.MethodsThis retrospective T2D cohort study used medical claims data for three DPP-4i regimens in patients newly prescribed DPP-4i between December 2016 and February 2019. Medication persistence rates were calculated at 3, 6, and 12 months by the Kaplan-Meier method. Adherence was measured as Proportion of Days Covered (PDC). We used Cox proportional hazards models for DPP-4i discontinuation and logistic regression models for non-adherence.ResultsIn the analysis population of 52,762 patients, DPP-4i prescriptions were 84.2% QD, 11.8% BID, and 4.0% QW. Medication persistence rates were similar up to 6 months for all regimens: approximately 90% at 3 and 80% at 6 months. The 12-month persistence rates for QD, BID, and QW were 74.8%, 67.5%, and 68.0%, respectively. Median PDC was 94.0% for QD, 91.8% for BID, and 93.2% for QW. Five specific factors were associated with discontinuation: BID or QW regimen, younger age, no concomitant medications, comorbid dementia, and comorbid chronic pulmonary disease. Non-adherence was associated with those factors plus male sex and treatment at clinics with 0-19 beds.ConclusionsThe 12-month medication persistence rates were highest for QD, followed by QW and then BID. Adherence was similar for all three regimens. Medication persistence for DPP-4i may be improved by tailoring regimens to patient characteristics and needs.