Our objectives were to measure long-term adherence to oral anticoagulants (OACs) in patients with atrial fibrillation (AF) and to identify patient factors associated with adherence. Using linked, population-based administrative data from British Columbia, Canada, an incident cohort of adults prescribed OACs for AF was identified. We calculated the proportion of days covered (PDC) as a time-dependent covariate for each 90-day window from OAC initiation until the end of follow-up. Associations between patient attributes and adherence were assessed using generalized mixed effect linear regression models. 30,264 patients were included. Mean PDC was 0.69 (SD 0.28) over a median follow-up of 6.7 years. 54% of patients were non-adherent (PDC < 0.8). After controlling for confounders, factors positively associated with adherence were number of drug class switches, history of stroke or transient ischemic attack, history of vascular disease, time since initiation, and age. Age > 75 years at initiation, polypharmacy (among VKA users only), and receiving DOAC (vs. VKA) were negatively associated with adherence. PDC decreased over time for VKA users and increased for DOAC users. Over half of AF patients studied were, on average, nonadherent to OAC therapy and missed 32% of their doses. Several patient factors were associated with higher or lower adherence, and adherence to VKA declined during therapy while DOAC adherence increased slightly over time. To min im ize the risk stroke, adherence-supporting interventions are needed for all patients with AF, particularly those aged > 75 years, those with prior stroke or vascular disease, VKA users with polypharmacy, and DOAC recipients.

我们的目标是衡量心房颤动 (AF) 患者对口服抗凝剂 (OAC) 的长期依从性，并确定与依从性相关的患者因素。使用来自加拿大不列颠哥伦比亚省的关联的、基于人群的管理数据，确定了一个为治疗房颤而开出 OAC 的成年人事件队列。我们计算了从 OAC 启动到随访结束的每个 90 天窗口的时间相关协变量覆盖天数 (PDC) 的比例。使用广义混合效应线性回归模型评估患者属性和依从性之间的关联。共纳入 30,264 名患者。中位随访时间为 6.7 年，平均 PDC 为 0.69 (SD 0.28)。 54% 的患者不依从 (PDC < 0.8)。控制混杂因素后，与依从性正相关的因素包括换药次数、中风或短暂性脑缺血发作史、血管疾病史、开始治疗后的时间和年龄。开始时年龄≥75岁、多药治疗（仅限 VKA 用户）和接受 DOAC（相对于 VKA）与依从性呈负相关。 VKA 用户的 PDC 随着时间的推移而减少，而 DOAC 用户的 PDC 则增加。平均而言，超过一半的研究 AF 患者没有坚持 OAC 治疗，并且错过了 32% 的剂量。一些患者因素与较高或较低的依从性相关，VKA 的依从性在治疗期间下降，而 DOAC 的依从性随着时间的推移略有增加。为了最大限度地降低中风风险，所有 AF 患者都需要采取依从性支持干预措施，特别是年龄大于 75 岁的患者、既往有中风或血管疾病的患者、接受多种药物治疗的 VKA 使用者和 DOAC 接受者。