Group-Based Trajectory Modeling to Evaluate Adherence Patterns for Direct Oral Anticoagulant Among Patients with Atrial Fibrillation

OBJECTIVES:

Direct oral anticoagulants (DOACs) are the standard of care to prevent stroke and systemic embolism among patients with atrial fibrillation (AF). However, suboptimal adherence with DOACs is a major problem and increases risk of thromboembolic events. Group-based trajectory modeling (GBTM) is a robust method to identify underlying variations in the longitudinal adherence pattern and has advantage over single estimates of Proportion of days covered (PDC). The objective of this study was to assess distinct trajectories of DOAC adherence using GBTM and identify predictors associated with adherence trajectories.

METHODS:

This retrospective study was conducted among Texas Medicare Advantage Plan patients with AF who were prescribed a DOAC from July 2016 - December 2017, with one-year follow-up. Monthly PDC was modelled into logistic GBTM and assessed using 2-5 adherence groups. The final model was selected based on Bayesian information criteria value and clinical relevance. A multinomial regression model was conducted to identify predictors associated with distinct trajectories using adherent trajectory as reference group.

RESULTS:

Among 1969 AF patients included in the analysis, four distinct adherence trajectories were identified: adherent (36.8%); gaps in adherence (9.3%); gradual decline in adherence (29.7%); and rapid decline in adherence (24.2%). Significant predictors with suboptimal adherence associated with rapid decline trajectory included gender (OR:1.36, 95% CI: 1.03-1.80) and low-income subsidy (OR:2.32, 95% CI: 1.79-3.00). Significant predictors correlated with gaps in adherence trajectory were age (OR:1.71, 95% CI: 1.06-2.74), low-income subsidy (OR:3.48, 95% CI: 2.29-5.27), prevalent users (OR:1.60, 95% CI: 1.08-2.36) and hypertension (OR:2.09, 95% CI: 1.05-4.16). Significant factors associated with gradual decline trajectory included low-income subsidy (OR:1.77, 95% CI: 1.40-2.24), renal disease (OR:1.73, 95% CI: 1.03-2.91), and NSAID use (OR:1.61, 95% CI: 1.01-2.60).

CONCLUSIONS:

Findings suggest that DOACs adherence was suboptimal. Predictors identified can aid clinicians in developing tailored interventions to improve patient’s adherence.