School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada.
Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
Syst Rev. 2019 Oct 28;8(1):245. doi: 10.1186/s13643-019-1175-5.
The optimal duration of anticoagulation after a first unprovoked venous thromboembolism (VTE) remains controversial. Deciding to stop or continue anticoagulant therapy indefinitely after completing 3 to 6 months of initial treatment requires balancing the long-term risk of recurrent VTE if anticoagulation is stopped against the long-term risk of major bleeding if anticoagulation is continued. However, knowledge of the long-term risk for major bleeding events during extended anticoagulation in this patient population is limited. We plan to conduct a systematic review and meta-analysis to quantify the risk for major bleeding events during extended oral anticoagulation in patients with first unprovoked VTE.
Electronic databases including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials will be systematically searched with the assistance of an information specialist (from inception to March 1, 2019) to identify randomized controlled trials and prospective cohort studies reporting major bleeding during extended oral anticoagulation in patients with first unprovoked VTE, who have completed at least 3 months of initial anticoagulant therapy. Study selection, risk of bias assessment, and data extraction will be performed independently by at least two investigators. The number of major bleeding events and person-years of follow-up will be used to calculate the rate (events per 100 person-years) with its 95% confidence interval for each study cohort, during clinically relevant time periods of extended anticoagulant therapy. Results will be pooled using random effect meta-analysis.
The planned systematic review and meta-analysis will provide reliable estimates of the risk for major bleeding events during extended anticoagulation. This information will help inform patient prognosis and assist clinicians with balancing the risks and benefits of treatment to guide management of unprovoked VTE.
PROSPERO CRD42019128597 .
首次无诱因静脉血栓栓塞症（VTE）后抗凝的最佳持续时间仍存在争议。在完成 3 至 6 个月初始治疗后，决定停止或无限期继续抗凝治疗，需要权衡停止抗凝治疗时 VTE 复发的长期风险，与继续抗凝治疗时发生大出血的长期风险。然而，在该患者人群中，延长抗凝期间发生大出血事件的长期风险知之甚少。我们计划进行一项系统评价和荟萃分析，以量化首次无诱因 VTE 患者延长口服抗凝期间发生大出血事件的风险。
在信息专家的协助下，系统检索电子数据库，包括 MEDLINE、EMBASE 和 Cochrane 对照试验中心注册库（从建立到 2019 年 3 月 1 日），以确定报告首次无诱因 VTE 患者在完成至少 3 个月初始抗凝治疗后延长口服抗凝期间发生大出血的随机对照试验和前瞻性队列研究。研究选择、偏倚风险评估和数据提取将由至少两名研究人员独立进行。将使用每个研究队列的主要出血事件数量和随访人数年来计算每个研究队列在延长抗凝治疗的临床相关时间段内每 100 人年的发生率（事件发生率）及其 95%置信区间。结果将使用随机效应荟萃分析进行汇总。
计划进行的系统评价和荟萃分析将提供延长抗凝期间发生大出血事件风险的可靠估计。这些信息将有助于告知患者预后，并帮助临床医生权衡治疗的风险和益处，以指导无诱因 VTE 的管理。
PROSPERO CRD42019128597 。
