Medication persistence and discontinuation of rivaroxaban and dabigatran etexilate among patients with non-valvular atrial fibrillation.

OBJECTIVE: To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and dabigatran in the US. METHODS: A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF on rivaroxaban or dabigatran between October 2010 and March 2013. The index date was the date of the first prescription of rivaroxaban or dabigatran. All patients had ≥6 months of data prior to the index date and were followed until the earliest of inpatient death, end of continuous enrollment, or end of the study period. Rivaroxaban patients were matched 1:1 with dabigatran patients using the propensity score matching technique. Cox proportional hazards models were employed to estimate the adjusted hazard ratios (aHRs) of non-persistence and discontinuation. Persistence was defined as absence of a refill gap of ≥60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. RESULTS: A total of 30,337 NVAF patients on rivaroxaban or dabigatran met the study criteria. All 7259 rivaroxaban patients were matched 1:1 to dabigatran patients. Compared with dabigatran users, rivaroxaban patients were 11% less likely to become non-persistent with therapy (aHR: 0.89, 95% CI 0.84-0.95) and 29% less likely to discontinue therapy (aHR: 0.71, 95% CI 0.66-0.77). LIMITATIONS: Claims data are subject to miscoding and inaccuracies. Refill data may not fully reflect actual medication taken. Confounding may remain even after propensity score matching and additional adjustments in model. Longer follow-up may produce more precise estimates of persistence and discontinuation. CONCLUSIONS: This matched cohort analysis indicated that, compared to dabigatran, rivaroxaban was associated with better persistence and lower rates of discontinuation.

Medication persistence and discontinuation of rivaroxaban versus warfarin among patients with non-valvular atrial fibrillation.

OBJECTIVES: To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and warfarin in the US. RESEARCH DESIGN AND METHODS: A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF treated with rivaroxaban or warfarin from 1 July 2010 through 31 March 2013. Index date was the date of the first prescription of rivaroxaban or warfarin. All patients were followed until the earliest of inpatient death, end of continuous enrollment, or end of study period. Rivaroxaban patients were matched 1:1 by propensity scores. Medication persistence was defined as absence of refill gap of ≥ 60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. Cox proportional hazards models were estimated to examine the adjusted hazard ratios (aHRs) of rivaroxaban vs. warfarin on non-persistence and discontinuation. RESULTS: A total of 32,886 NVAF patients on rivaroxaban or warfarin met the study inclusion criteria. Each of the 7259 rivaroxaban patients identified were matched 1:1 to warfarin patients. Patients on rivaroxaban had a significantly better rate of persistence (aHR: 0.63, 95% CI 0.59-0.68) and lower rate of discontinuation (aHR: 0.54, 95% CI 0.49-0.58) compared to warfarin recipients. LIMITATIONS: Claims data may have contained inaccuracies and miscoding. Confounding may remain even after propensity score matching and additional adjustments in model. Refill data may not fully reflect actual medication use. Longer follow-up may produce more precise estimates of persistence and discontinuation. CONCLUSION: This matched cohort analysis indicated that rivaroxaban was associated with significantly higher medication persistence and lower discontinuation rates compared to warfarin.

Real-world comparative effectiveness and safety of rivaroxaban and warfarin in nonvalvular atrial fibrillation patients.

BACKGROUND: Rivaroxaban was shown to be effective in reducing the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (AF) in a randomized controlled trial setting. OBJECTIVE: To assess real-world safety, effectiveness, and persistence associated with rivaroxaban and warfarin in nonvalvular AF patients. METHODS: Healthcare claims from Symphony Health Solutions' Patient Transactional Datasets from May 2011 to July 2012 were analyzed. Adult patients newly initiated on rivaroxaban or warfarin, with ≥2 AF diagnoses (ICD-9-CM: 427.31) and a CHADS2 score ≥1 during the 180 day baseline period were included. Cohorts were matched 1:4 using propensity score methods. Study outcomes were major bleeding, intracranial hemorrhage (ICH), gastrointestinal (GI) bleeding, composite stroke and systemic embolism, and venous thromboembolism (VTE) events. Cox proportional hazard models were used to compare event and persistence rates. RESULTS: The matched sample included 3654 rivaroxaban and 14,616 warfarin patients. Matching was adequate, with all standardized differences in patient characteristics <10%. No significant differences were observed for bleeding and composite stroke and systemic embolism outcomes, although rivaroxaban users were associated with significantly fewer VTE events (hazard ratio [HR] = 0.36, 95% confidence interval [CI]: 0.24-0.54, p < 0.0001) compared to warfarin users. Rivaroxaban was also associated with a significantly lower risk of treatment non-persistence (HR = 0.66; 95% CI: 0.60-0.72, p < 0.0001). LIMITATIONS: Claims data may have contained inaccuracies, and mortality and laboratory data were not available. Confounding may still have been possible even after propensity score matching. Early use pattern of medications may have changed over time. CONCLUSION: This analysis suggests that rivaroxaban and warfarin do not differ significantly in real-world rates of composite stroke and systemic embolism and major, intracranial, or GI bleeding. Rivaroxaban, however, was associated with significantly fewer VTE events and significantly better treatment persistence compared with warfarin.

Initiation of rivaroxaban following low molecular weight heparin for thromboprophylaxis after total joint replacement: the Safe, Simple Transitions (SST) study.

INTRODUCTION: No data are available regarding appropriate strategies for the transition of patients undergoing total hip or knee replacement (THR/TKR) surgery from subcutaneous low molecular weight heparin (LMWH) to rivaroxaban. This study determined the pharmacodynamic effects of rivaroxaban on the first day of administration compared with serial administration in patients who had transitioned to rivaroxaban 22-28 hours after the last once-daily LMWH dose (or 12-18 hours after the last twice-daily LMWH dose). METHODS: Patients undergoing THR or TKR surgery who had received at least one post-operative LMWH dose were included in this open-label, single-arm, multicentre study. Measurements of anti-Factor Xa activity and prothrombin time were made on the first and third days of daily rivaroxaban administration. The effects of age and renal function on these parameters, and safety and tolerability, were assessed. RESULTS: Fifty-six patients were enrolled in the Safe, Simple Transitions (SST) study; 52 patients comprised the intention-to-treat population. Mean anti-Factor Xa activity increased slightly but significantly from day 1 to day 3, whereas the area under the concentration-time curve (AUC) was similar on days 1 and 3. Mean prothrombin time was slightly prolonged on day 1 compared with day 3; the AUC was significantly increased (p<0.0001). The pharmacodynamic effects of rivaroxaban were slightly increased in older patients and those with reduced renal function. There were no cases of venous thromboembolism or bleeding and no unexpected adverse events. CONCLUSION: Initiating rivaroxaban approximately 12 or 24 hours after the last LMWH dose (as appropriate) provides a simple, well-tolerated transition strategy for thromboprophylaxis in patients undergoing THR/TKR surgery.