Risk factors for amputation are influenced by competing risk of death in patients with critical limb ischemia
Risk factors for amputation are influenced by competing risk of death in patients with critical limb ischemia
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DOI：
10.1016/j.jvs.2019.07.074
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发表时间：
2020-04-01
影响因子：
4.3
通讯作者：
Malmstedt, Jonas
中科院分区：
文献类型：
--
作者：
Torbjornsson, Eva;Blomgren, Lena;Malmstedt, Jonas
目的：重度肢体缺血（CLI）患者是截肢和死亡的高危患者。死亡是影响估计截肢风险的竞争风险。我们的目的是通过竞争风险分析找到CLI患者截肢的具体危险因素，并将这些结果与标准Cox回归分析的结果进行比较。方法：从瑞典国家血管外科登记处确定斯德哥尔摩接受CLI血运重建术的患者（2009-2013年，随访数据至2017年）。主要结果是主要截肢。采用竞争风险分析评估截肢的危险因素，并与采用Cox比例风险回归分析确定的无截肢生存危险因素进行比较。结果：855例CLI患者中，178例需要进行大截肢，415例在8年随访期间死亡。在竞争风险回归中，年龄（亚分布风险比[亚hr]， 0.98； 95%可信区间[CI]， 0.97-1.00）、活动状态（独立与卧床；亚hr， 4.10; 95% CI, 2.14-7.86）和缺血性伤口与休息疼痛（亚hr， 3.03; 95% CI, 1.72-5.36）与截肢相关，将死亡视为竞争风险。相反，Cox回归分析发现女性与男性（风险比[HR]， 0.77; 95% CI, 0.64-0.94）、年龄（HR, 1.02; 95% CI, 1.01-1.03）、肾功能损害（HR, 2.08; 95% CI, 1.61-2.67）、活动状态（独立vs卧床；HR, 3.45; 95% CI, 2.30-5.18）、缺血性伤口vs静息性疼痛（HR, 2.41; 95% CI, 1.78-3.25）为危险因素。结论：使用竞争风险回归和Cox回归分析数据时，与截肢相关的危险因素有所不同。分析之间的差异表明，当存在死亡等强烈竞争风险时，使用标准生存方法进行有偏差估计存在风险。
Objective: Patients with critical limb ischemia (CLI) have a high risk of amputation and death. Death is a competing risk that affects the estimated amputation risk. Our aim was to find the specific risk factors for amputation for patients with CLI using competing risk analyses and compared these results with those from standard Cox regression analysis.Methods: Patients who had undergone revascularization for CLI (2009-2013, with follow-up data until 2017) in Stockholm were identified from the Swedish National Registry for Vascular Surgery. The main outcome was major amputation. The risk factors for amputation were assessed using competing risk analysis and compared with the risk factors for amputation-free survival identified using Cox proportional hazards regression analysis.Results: Of 855 patients with CLI, 178 had required a major amputation and 415 had died during the 8-year follow-up period. In the competing risk regression, age (subdistribution hazard ratio [sub-HR], 0.98; 95% confidence interval [CI], 0.97-1.00), ambulatory status (independent vs bedridden; sub-HR, 4.10; 95% CI, 2.14-7.86), and ischemic wound vs rest pain (sub-HR, 3.03; 95% CI, 1.72-5.36) were associated with amputation, considering death as a competing risk. In contrast, Cox regression analysis identified female vs male (hazard ratio [HR], 0.77; 95% CI, 0.64-0.94), age (HR, 1.02; 95% CI, 1.01-1.03), renal impairment (HR, 2.08; 95% CI, 1.61-2.67), ambulatory status (independent vs bedridden; HR, 3.45; 95% CI, 2.30-5.18), and ischemic wound vs rest pain (HR, 2.41; 95% CI, 1.78-3.25) as risk factors.Conclusions: The risk factors associated with amputation differed when analyzing the data using competing risk regression vs Cox regression. The differences between the analyses indicated that a risk exists for biased estimates using standard survival methods when a strong competing risk such as death is present.