Centre for Clinical Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Côte Sainte-Catherine Road, Montreal, QC H3T 1E2, Canada.
Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal QC H3A 2B4, Canada.
Eur Heart J. 2017 May 14;38(19):1473-1479. doi: 10.1093/eurheartj/ehw613.
In patients with non-valvular atrial fibrillation (NVAF), it is uncertain whether the higher risk of ischaemic stroke in women reported in some studies is due to residual confounding. We assessed this association using standard time-fixed and more accurate time-dependent adjustment for confounders.
Using the computerized databases of the Régie de l'assurance maladie du Québec (RAMQ), we identified a cohort of patients with NVAF during 2000-2009 and RAMQ medication coverage. Cox proportional hazards models were used to estimate the hazard ratio (HR) of ischaemic stroke, death, and bleeding, associated with sex, adjusting for time-fixed covariates at cohort entry. This was compared with adjustment for time-dependent covariates using an age and time-matched nested case-control analysis. The cohort included 147 622 patients. During a mean follow-up of 2.9 years 11 326 patients had a stroke (incidence rate 2.6 per 100 per year). Using time-fixed adjustment for confounders, women had a moderately higher risk of ischaemic stroke than men (HR 1.16 (Confidence interval (CI) 95% 1.11-1.21). Matching on age and using time-dependent adjustment for confounders, women were not at higher risk of stroke than men (Rate Ratio 1.01; 95% CI 0.97-1.05). Mortality and bleeding rates were lower in women compared with men in both analyses.
In NVAF, women were not at higher risk of thromboembolic events than men in our study. The small increased risk reported in previous studies may be related to residual confounding, in particular from insufficient control for age.
在非瓣膜性心房颤动（NVAF）患者中，一些研究报告女性发生缺血性卒中的风险较高，其原因是否归因于残留混杂因素尚不确定。我们使用标准的时间固定调整和更准确的时间相关调整来评估这种关联。
利用魁北克省健康保险局（RAMQ）的计算机数据库，我们确定了 2000-2009 年 NVAF 患者队列和 RAMQ 药物覆盖范围。使用 Cox 比例风险模型来估计缺血性卒中、死亡和出血的风险比（HR），其与性别相关，在队列入组时调整时间固定协变量。将其与使用年龄和时间匹配嵌套病例对照分析进行的时间相关协变量调整进行比较。该队列包括 147622 名患者。在平均 2.9 年的随访中，有 11326 名患者发生了卒中（发生率为 2.6/100 人年）。使用时间固定调整混杂因素，女性缺血性卒中的风险略高于男性（HR 1.16（95%CI 95% 1.11-1.21））。在年龄匹配的情况下，并使用时间相关调整混杂因素，女性发生卒中的风险并不高于男性（率比 1.01；95%CI 0.97-1.05）。在这两种分析中，女性的死亡率和出血率均低于男性。
在 NVAF 中，与男性相比，女性在我们的研究中没有更高的血栓栓塞事件风险。以前研究报告的风险略有增加可能与残留混杂因素有关，特别是与年龄控制不足有关。
