Division of Vascular Surgery, Department of Surgery, University of California Davis School of Medicine, Davis, CA.
Department of Public Health Sciences, University of California Davis School of Medicine, Davis, CA.
J Vasc Surg. 2023 Jun;77(6):1760-1775. doi: 10.1016/j.jvs.2023.01.200. Epub 2023 Feb 8.
Estimates of chronic limb-threatening ischemia (CLTI) based on diagnosis codes of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) suggest a prevalence of 0.23%-0.32% and incidence of 0.20%-0.26% among Medicare patients. ICD-10-CM includes 144 CLTI diagnosis codes, allowing improved specificity in identifying affected patients. We sought to use ICD-10-CM diagnosis codes to determine the prevalence of CLTI among Medicare patients and describe the patient cohort affected by this condition.
Using two years of data from Centers for Medicare and Medicaid Services, we identified all patients that had at least one CLTI diagnosis code to determine prevalence and incidence rates. Sensitivity analyses were performed to compare our methodology to prior publications and quantify the extent of missed diagnoses. The number and type of vascular procedures that occurred after diagnosis were tabulated. A cohort of patients with two or more CLTI diagnosis codes were then identified for further descriptive analysis. Associations between patient demographics and survival were analyzed using Cox proportional hazards models.
Over 65 million patients were enrolled in Medicare in 2017 to 2018. Of these, 480,227 had diagnosis of CLTI, with a corresponding to a 1-year incidence of 0.33% and a 2-year prevalence of 0.74%. Patients underwent an average of 43.6 vascular procedures per 100 person-years. Sensitivity analyses identified 89,805 additional patients that had a diagnosis code of peripheral arterial disease who underwent revascularization or amputation. Patients with CLTI were predominantly male (56.2%), white (76.4%), and qualified for Medicare due to age (64.0%). Thirty-seven percent were dual-eligible. One-year survival was 77.7%, significantly lower than estimated actuarial survival adjusted for age, sex, and race (95.1%; P < .001). Cox proportional hazards models demonstrate significantly increased mortality for men vs women (hazard ratio, 1.07; 95% confidence interval, 1.04-1.10; P < .001), but no association between race and overall survival (hazard ratio, 0.99; 95% confidence interval, 0.98-1.01; P = .83).
Using ICD-10-CM diagnosis codes, we demonstrated slightly higher incidence and prevalence of CLTI than in published literature, reflecting our more complete methodology. Sensitivity analyses suggest that increased complexity of the highly specific ICD-10-CM coding may diminish capture of CLTI. Inclusion of patients with non-CLTI peripheral arterial disease diagnoses produces moderate increases in incidence and prevalence at the cost of decreased specificity in identifying patients with CLTI. Medicare patients with CLTI are older, and more commonly male, black, and dual eligible compared with the general Medicare population. Observed mid-term survival for patients with CLTI is significantly lower than actuarial estimates, confirming the importance of focused efforts on identifying and aligning goals of care in this complex patient population.
基于国际疾病分类，第九修订版，临床修正（ICD-9-CM）的诊断代码估计，医疗保险患者中慢性肢体威胁性缺血（CLTI）的患病率为 0.23%-0.32%，发病率为 0.20%-0.26%。ICD-10-CM 包含 144 个 CLTI 诊断代码，可提高识别受影响患者的特异性。我们试图使用 ICD-10-CM 诊断代码来确定医疗保险患者中 CLTI 的患病率，并描述受此疾病影响的患者队列。
使用医疗保险和医疗补助服务中心两年的数据，我们确定了至少有一个 CLTI 诊断代码的所有患者，以确定患病率和发病率。进行了敏感性分析，以比较我们的方法与先前的出版物，并量化漏诊的程度。还列出了诊断后发生的血管程序的数量和类型。然后确定了具有两个或更多 CLTI 诊断代码的患者队列，以进行进一步的描述性分析。使用 Cox 比例风险模型分析了患者人口统计学特征与生存之间的关系。
在 2017 年至 2018 年期间，有超过 6500 万患者参加了医疗保险。其中，有 480227 人被诊断为 CLTI，相应的 1 年发病率为 0.33%，2 年患病率为 0.74%。患者每 100 人年平均进行 43.6 次血管程序。敏感性分析确定了另外 89805 名接受血管重建或截肢的诊断为外周动脉疾病并有诊断代码的患者。CLTI 患者主要为男性（56.2%），白人（76.4%），并因年龄（64.0%）获得医疗保险。37%为双重资格。一年生存率为 77.7%，明显低于根据年龄、性别和种族调整的预计精算生存率（95.1%；P<0.001）。Cox 比例风险模型显示男性的死亡率明显高于女性（风险比，1.07；95%置信区间，1.04-1.10；P<0.001），但种族与总生存率之间无关联（风险比，0.99；95%置信区间，0.98-1.01；P=0.83）。
使用 ICD-10-CM 诊断代码，我们的研究表明 CLTI 的发病率和患病率略高于已发表的文献，这反映了我们更完整的方法。敏感性分析表明，高度特异性的 ICD-10-CM 编码的复杂性增加可能会降低 CLTI 的捕获率。包括非 CLTI 外周动脉疾病诊断的患者会适度增加发病率和患病率，但会降低识别 CLTI 患者的特异性。与一般医疗保险人群相比，患有 CLTI 的医疗保险患者年龄较大，更常见的是男性、黑人、双重资格。CLTI 患者的中期生存率明显低于精算估计，这证实了在这一复杂患者群体中，有必要集中精力确定并调整治疗目标。
