Influence of co-initiation of antiulcer drugs on persistence and adherence to low-dose aspirin: A retrospective cohort study using a Japanese claims database .

Objective: The purpose of this study was to examine whether co-initiation of antiulcer drugs (AUDs) and low-dose aspirin (LDA) therapy is beneficial for good adherence to LDA therapy.

Materials And Methods: A retrospective cohort study was conducted using the JMDC claims database. Patients for whom LDA therapy was newly initiated between January 2005 and April 2016 were selected from the JMDC database. The selected patients were divided into LDA and LDA+AUD groups and were followed up from the first prescription of LDA or LDA+AUD until the earliest of the following events: discontinuation or the end of the observation period. Unadjusted and multivariable Cox proportional hazards models controlling for all demographic and clinical characteristics were applied to examine whether the addition of an AUD to LDA improved adherence. A 1 : 1 propensity score matching analysis was conducted to balance confounders between the two groups.

Results: After the propensity score matching analysis, 4,089 patients were matched in each therapy group. The Kaplan-Meier curves for the rate of LDA continuation showed a sharp decline just after the initiation of LDA therapy. A significant difference was observed in the incidence of LDA therapy discontinuation between the LDA+AUD and LDA groups (HR: 0.87, 95% CI: 0.82 - 0.92), and the median duration of LDA therapy in the LDA+AUD and LDA groups were 18 and 11 months (log-rank test: p < 0.0001), respectively.

Conclusion: The therapy persistence rate in the LDA+AUD group was significantly higher than that in the LDA group.