Primary care provider payment models and adherence to anticoagulation in patients with atrial fibrillation

BACKGROUND: Oral anticoagulation (OAC) is recommended for the prevention of stroke in atrial fibrillation (AF). However, only 50%-60% of AF patients in the United States are treated with OAC, and 60% of them adhere to OAC therapy over time. OBJECTIVES: To (1) compare adherent use of OAC between AF patients who received primary care from practices involved in shared-savings models and patients who received care from practices not involved in shared savings and (2) examine the trend of adherence to OAC over time. Because OAC can save downstream medical costs associated with averted stroke events, we hypothesized that OAC adherence would be higher among patients receiving care from practices involved in shared savings. METHODS: Using 2014-2019 claims data from a health insurer in western Pennsylvania, we identified 20,637 AF patients from 2015-2018. Patients were followed from the first AF diagnosis (index date) for 12 months or until disenrollment. We categorized patients according to the payment model of the practice from which they received primary care: shared savings (n = 8,844) and no shared savings (n = 11,793). The primary outcome was adherent use of OAC therapy, which was defined as having at least 80% of the followup period covered with OAC. Secondary outcomes included adherent use of direct oral anticoagulants (DOACs) and adherent use of warfarin. We constructed logistic regression models to assess the association between involvement in shared savings and adherent use of OAC, while controlling for demographics, clinical characteristics, and index year. RESULTS: 34% of patients in the shared-savings group adhered to OAC, compared with 32.7% in the no shared-savings group (P = 0.04). After adjustment, adherence was higher for the shared-savings group for OAC (adjusted odds ratio [aOR] = 1.07, 95% CI = 1.01-1.14) and warfarin (aOR = 1.11, 95% CI = 1.02-1.20) compared with the no shared-savings group. However, the odds of adherent use of DOACs did not statistically differ between shared savings and no shared savings (aOR = 0.99, 95% CI = 0.91-1.08). The odds of adherent OAC use increased over time: the aOR of adherent use of OAC was 1.21 (95% CI = 1.09-1.34) for index year 2016; 1.50 (95% CI = 1.36-1.67) for 2017; and 1.78 (95% CI 1.60-1.98) for 2018, all compared with 2015. CONCLUSIONS: Receipt of primary care from a practice involved in shared savings was associated with a higher adherent use of OAC and warfarin for patients with atrial fibrillation. Furthermore, adherent use of OAC improved over time for both treatment groups. Our research demonstrates that the alignment of financial incentives between providers and insurers may improve the use of therapies with downstream cost-saving potential.