OBJECTIVES : In the AMPLIFY trial, apixaban was non-inferior to conventional therapy (subcutaneous enoxaparin, followed by warfarin) for treatment of acute VTE, with significantly less bleeding. This observational study compared healthcare expenditures between patients receiving outpatient pharmacotherapy with apixaban versus warfarin for VTE in US clinical practice.

METHODS : A retrospective matched-cohort design and pooled data from four large US private healthcare claims databases (03/2014 – 06/2017) were employed. From the source population including adults who had an initial VTE diagnosis and, within 30 days, began outpatient anticoagulant treatment, patients receiving apixaban were matched 1:1 (without replacement) to those receiving warfarin plus parenteral anticoagulant bridge therapy; matching was performed on the basis of age, study database, VTE characteristics, and propensity score (nearest-neighbor approach). Healthcare expenditures (2017US$) for all causes, major bleeding, and recurrent VTE during (max.) 180-day follow-up period were totaled within each treatment group, and along with corresponding differences, were expressed per patient per month (PPPM); 95% confidence intervals (CIs) were generated via non-parametric bootstrapping.

RESULTS : Study population included 17,878 matched pairs of apixaban and warfarin patients; treatment groups were well balanced on baseline characteristics. PPPM (95% CI) all-cause healthcare expenditures were significantly higher among warfarin versus apixaban patients ($4,247 [4,106-4,369] vs. $3,838 [3,683-4,027]; difference = $409 [180-608]), which was attributable to increased expenditures in the inpatient and ambulatory settings ($3,811 [3,679-3,936] vs. $3,194 [3,036-3,388]; difference = $617 [389-816]). PPPM healthcare expenditures for major bleeding were also significantly higher among warfarin patients ($192 [154-244] vs. $130 [101-161]; difference = $62 [18-119]). PPPM expenditures for recurrent VTE were not statistically different between treatment groups ($104 [83-125] vs. $114 [84-156]; difference = -$10 [-57-19]).

CONCLUSIONS : In this large retrospective observational study of VTE patients receiving outpatient apixaban or warfarin in US clinical practice, all-cause and major bleeding-related healthcare expenditures were significantly higher among patients who received warfarin.