新型抗凝药与华法林用于非瓣膜性房颤患者卒中防治的成本效果分析

目的:评估中国非瓣膜性房颤患者使用新型抗凝药预防卒中的成本效果,为中国房颤患者抗凝治疗药物的合理选用提供理论依据。方法:基于全球性临床试验ARISTOTLE、RE-LY及ROCKET-AF的研究数据及我国目前医疗成本,建立一年期决策树及长期外推Markov模型的方法,通过分别计算3种新型口服抗凝药物阿哌沙班(5 mg bid)、达比加群(150 mg bid、110 mg bid)、利伐沙班(20 mg qd)和华法林的调整质量生命年(QLAYs)及治疗成本,对新型抗凝药物用于中国房颤患者卒中预防的成本效果进行了分析和研究。结果:NOACs治疗的总成本为163586~582710元,使用NOACs患者可获得的质量调整生命年为6.812~7.010。以华法林为参考的增效成本效果分析显示,成本效果比(ICER)为177271~739480元/QLAY,ICER_利伐沙班> ICER_阿哌沙班> ICER_{达比加群150 mg}> ICER_{达比加群110 mg}。3种抗凝药物与华法林比较的ICER均大于我国人均国民生产总值(GDP)的3倍,但小于部分城市人均GDP的3倍。一维敏感度分析显示该成本效果分析结果稳定可靠。结论:目前在我国,与华法林相比,使用新型抗凝药物预防非瓣膜性房颤患者卒中不具备成本效果优势。目前仅在我国经济发达的某些城市,可推荐阿哌沙班或达比加群用于房颤卒中的治疗。     

Risk of major bleeding in patients with non-valvular atrial fibrillation treated with oral anticoagulants: a systematic review of real-world observational studies

Objective: To conduct a systematic review of real-world (RWD) studies comparing the risk of major bleeding (MB) among patients with non-valvular atrial fibrillation (NVAF) on direct oral anticoagulants (DOACs) or warfarin.

Methods: MEDLINE, Embase, NHS-EED, and EconLit were searched for RWD studies published between January 2003 and November 2016 comparing MB risk among DOACs and warfarin. Proceedings of clinical conferences from 2012 to 2016 were reviewed.

Results: A total of 4218 citations were identified, 26 of which met eligibility criteria. Most studies were retrospective analyses of administrative claims databases and patient registries (n?=?23 of 26); about half were based in the United States (n?=?15). Apixaban showed a significantly lower risk of MB versus warfarin in all eight included studies. MB risk was either significantly lower (n?=?9 of 16) or not significantly different (n?=?7 of 16) between dabigatran and warfarin; there was no significant difference between rivaroxaban and warfarin in all seven included studies. The risk was significantly lower with apixaban versus rivaroxaban (n?=?7 of 7) but not significantly different from dabigatran (n?=?6 of 7). MB risk was significantly lower (n?=?3 of 4) or not significantly different (n?=?1 of 4) with dabigatran versus rivaroxaban. No evidence was identified for edoxaban.

Conclusion: DOACs were associated with similar or lower risks of MB versus warfarin. A lower MB risk was consistently observed for apixaban, but less consistently for dabigatran; MB risk was similar between rivaroxaban and warfarin. Among DOACs, the risk of MB with apixaban was consistently lower than with rivaroxaban, but similar to dabigatran.     

Stroke risk reduction outweighed bleeding risk increase from vitamin K antagonist treatment among nonvalvular atrial fibrillation patients with high stroke risk and low bleeding risk

Objective: Warfarin is widely used for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). We compared the rates of stroke and major bleeding in NVAF patients with a high stroke risk and low bleeding risk profile during warfarin treated (W+) and warfarin untreated (W?) periods.

Method: Insurance claims from six commercial, Medicaid or Medicare databases were analyzed from 2000 to 2014. NVAF patients treated with warfarin, with a CHADS₂/CHA₂DS₂-VASc score ≥2, and an ATRIA score ≤3 at baseline were identified. Incidence rate ratios (IRRs) of stroke and major bleeding were calculated for W?+?versus W? episodes of person-time, as well as for first 30 days versus beyond 30 days of W?+?episodes.

Results: Among 316,145 patients, anticoagulant prophylaxis with warfarin significantly reduced stroke risk, with IRRs ranging from 0.48 (95% CI: 0.46–0.51) to 0.80 (95% CI: 0.70–0.91), and increased major bleeding risk, with IRRs ranging from 1.13 (95% CI: 1.10–1.15) to 1.95 (95% CI: 1.10–3.45). Stroke and major bleeding rates were higher during the first 30 days of W?+?than beyond.

Conclusion: In NVAF patients at high risk for stroke and low risk for bleeding, our data confirm the effectiveness of anticoagulation for stroke prevention. The decrease in stroke risk of anticoagulation may outweigh the risk of major bleeding events, particularly among elderly patients. Potential risks of warfarin during initiation warrant attention, especially among patients who stop and start therapy repeatedly.     

Impact of methodological choices on a meta-analysis of real-world evidence comparing non-vitamin-K antagonist oral anticoagulants with vitamin K antagonists for the treatment of patients with non-valvular atrial fibrillation

Objective: The aim of this study was to investigate the impact of methodological choices in a meta-analysis of real-world evidence (RWE) comparing three non-vitamin-K antagonist oral anticoagulants with vitamin K antagonists (VKAs) for the treatment of patients with non-valvular atrial fibrillation (NVAF).

Methods: The meta-analysis was based on a systematic review of RWE studies enrolling incident and prevalent patients aged ≥18 years with NVAF and receiving either rivaroxaban, dabigatran, apixaban or a VKA. Five different scenarios were considered to explore the impact of the initial meta-analysis assumptions: (1) using studies that involved only incident patients; (2) excluding studies that only reported crude values and did not consider any adjustment; (3) including all studies independently of possible database overlap; (4) using studies with data on different dosages for rivaroxaban and dabigatran; and (5) assigning quality weights to studies to assess quality of reporting. These scenarios were run on three outcomes: ischemic stroke (IS), myocardial infarction (MI) and intracranial hemorrhage (ICH).

Results: Across all scenarios, rivaroxaban was associated with significantly lower risks of IS and ICH than VKAs. In most scenarios, dabigatran was associated with significantly lower risks of IS and ICH. In all scenarios, apixaban was associated with a significantly lower risk of ICH.

Conclusions: Sensitivity analyses showed the impact of similar assumptions was different depending on the outcome and the drug considered. The development of recommendations and guidelines for the inclusion of RWE in meta-analyses could prove useful in evaluating the effectiveness of health care interventions.     

Cost-effectiveness analysis of dabigatran versus rivaroxaban for stroke prevention in patients with non-valvular atrial fibrillation using real-world evidence in elderly US Medicare beneficiaries

Objective: Dabigatran and rivaroxaban have been approved by the US FDA to reduce the risk of stroke and systemic embolism in non-valvular atrial fibrillation (NVAF) patients. Newly published real-world evidence based on the US population found that elderly Medicare patients with NVAF treated with rivaroxaban experienced statistically significant increases in intracranial hemorrhage (ICH) and major extracranial bleeding, and statistically nonsignificant decreases in thromboembolic stroke and acute myocardial infarction (AMI) compared with dabigatran. This study assessed the cost-effectiveness of dabigatran vs. rivaroxaban for the treatment of US Medicare NVAF patients.

Methods: A previously published Markov model was adapted to compare dabigatran and rivaroxaban. The model considered thromboembolic stroke, bleeding events, and AMI based on the published real-world event risks. Model outputs included clinical event rates, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).

Results: Dabigatran patients experienced fewer ICH and major extracranial bleeding events than rivaroxaban patients, but more stroke and AMI events. Dabigatran was found to yield lower costs and higher QALYs than rivaroxaban, with incremental costs of ?$3534 and incremental QALYs of 0.004. Results remained consistent in sensitivity analyses, with a positive net monetary benefit (willingness-to-pay thresholds of $50,000 and $100,000 per QALY) for dabigatran over rivaroxaban for all model inputs tested.

Conclusions: In this study using US Medicare real-world data, dabigatran was found to dominate rivaroxaban. The analyses were limited by the short follow-up period of the real-world data and results may not be generalizable to other patient populations.     

Strategies for improving dabigatran adherence for stroke prevention in patients with non-valvular atrial fibrillation: education and drug intake reminders (FACILITA study)

Objective To assess the efficacy of a mixed intervention, educational, and reminder calendar of the intake, as a strategy to improve therapeutic adherence with dabigatran in patients with non-valvular atrial fibrillation (NVAF).

Methods This was a prospective, longitudinal, multi-center study, carried out in 110 specialized healthcare centers in Spain. Seven hundred and twenty-six patients treated with dabigatran prescribed for stroke prevention were included. A cluster randomization was performed based on two groups: (1) Control Group (CG) as usual clinical practice, and (2) Intervention Group (IG) with a mixed strategy: (a) Healthcare education, and (b) Use of a reminder calendar for taking the anticoagulant medication. Three visits took place: baseline and follow-up at 6 and 12 months. Compliance was measured by using electronic monitors (MEMS). Average adherence percentage (%; Average AP) and daily compliance (%; Daily AP) was calculated. A patient was considered adherent when AP was 80–100%.

Results Six hundred and twenty-five patients completed the study (315 in the IG and 310 in the CG). Daily AP was 91.97% at 6 months and 91.05% after 12 months in the IG and 82.26% and 82.63% in the CG. Average adherence was 90.79% and 89.20% in the IG and 64.51% and 63.22% in the CG at 6 and 12 months, respectively. Significant differences were observed in the Daily AP and Average AP, with higher percentages in the IG. In the non-adherents group, the number of concomitant drugs, baseline, and 6 months SBP values, 6 and 12 months DBP values, and weight, total cholesterol, and LDL cholesterol were significantly higher. The number needed to treat (NNT) was 3.84 patients to prevent one non-adherence.

Conclusions A mixed intervention, consisting of patient education and a simple calendar reminder of drug intake, is an effective strategy to improve dabigatran therapeutic adherence in patients with NVAF. The percentage of adherence with dabigatran was high.