Abstract 242: Healthcare Resource Utilization and Costs among Patients with Non-Valvular Atrial Fibrillation using Dabigatran or Warfarin For Stroke Prevention
Authors: Fu An-Chen , Jain Rahul , Sander Stephen D , Lim Jonathan , Jain Gagan , Yu Yanni , Tan Hiangkiat 
Published: March 2022

Background:
Dabigatran was the first novel oral anticoagulant (OAC) approved in the US for stroke risk reduction in patients with non-valvular atrial fibrillation (NVAF). The aim of this study was to evaluate the healthcare resource utilization (HCRU) and costs among newly diagnosed NVAF patients who were newly treated with dabigatran or warfarin in the real world setting.

Methods:
Medical and pharmacy claims from the HealthCore Integrated Research Database were used to identify NVAF patients who initiated dabigatran or warfarin during 10/1/2010-12/31/2011. The index date was defined as the date of first OAC claim during this period. Newly diagnosed (first AF diagnosis within 3 months prior to index date) and newly treated (no OAC claim within 12 months prior to index date) patients with continuous 12-month health plan enrollment before index date were identified. HCRU (all-cause office visits (OV), emergency room (ER) visits, hospitalizations (INP)) and costs (in 2013 US$) were measured in per-patient-per-month (pppm) from the index date to the date of discontinuation/switch, health plan disenrollment, death, or end of 12 months, whichever came first. The dabigatran and warfarin cohorts were matched on baseline characteristics using propensity scores. The unadjusted HCRU, pharmacy and medical costs of the matched cohorts were compared using the Wilcoxon signed-rank test. Differences in adjusted total healthcare costs (sum of pharmacy and medical costs) between cohorts were assessed using a generalized linear model with log link and gamma variance function. A sensitivity analysis on previously diagnosed (first AF diagnosis between 12 and 3 months prior to index date), newly treated NVAF patients was also performed.

Results:
There were 824 matched patients in each cohort (mean age 64±12 years, 67% males). The dabigatran cohort had similar numbers of all-cause INP (mean±SD pppm: 0.08±0.20 vs. 0.09±0.29, p=0.866) and ER visits (mean±SD pppm: 0.04±0.13 vs. 0.04±0.14, p=0.760) but significantly fewer OV (mean±SD pppm: 1.29±0.95 vs. 2.02±1.53, p<0.001) compared to the warfarin cohort. The dabigatran cohort had significantly higher pharmacy costs than the warfarin cohort (mean±SD pppm: $455±429 vs. $328±517, p<0.001) but similar medical costs (mean±SD pppm: $2,696±6,699 vs. $2,893±6,819, p=0.179). There was no difference in the adjusted total healthcare costs between the two cohorts (mean pppm cost, dabigatran vs. warfarin: $2949 vs. $2959; percentage difference in costs: -0.35% [95%CI:-17.24% to 19.98%], p=0.970). The analysis on previously diagnosed, newly treated NVAF patients showed similar results.

Conclusions:
Although newly diagnosed, newly treated NVAF patients initiated on dabigatran had higher pharmacy costs than those on warfarin, the total healthcare costs were similar between the two cohorts. In addition, fewer office visits were observed in the dabigatran cohort.