Abstract：
OBJECTIVE: Prior studies have described risk factors associated with amputation in patients with concomitant diabetes and peripheral arterial disease (DM/PAD). However, the association between the severity and extent of tissue loss type and amputation risk remains less well-described. We aimed to quantify the role of different tissue loss types in amputation risk among patients with DM/PAD, in the context of demographic, preventive, and socioeconomic factors.
METHODS: Applying International Classification of Diseases (ICD)-9 and ICD-10 codes to Medicare claims data (2007-2019), we identified all patients with continuous fee-for-service Medicare coverage diagnosed with DM/PAD. Eight tissue loss categories were established using ICD-9 and ICD-10 diagnosis codes, ranging from lymphadenitis (least severe) to gangrene (most severe). We created a Cox proportional hazards model to quantify associations between tissue loss type and 1- and 5-year amputation risk, adjusting for age, race/ethnicity, sex, rurality, income, comorbidities, and preventive factors. Regional variation in DM/PAD rates and risk-adjusted amputation rates was examined at the hospital referral region level.
RESULTS: We identified 12,257,174 patients with DM/PAD (48% male, 76% White, 10% prior myocardial infarction, 30% chronic kidney disease). Although 2.2 million patients (18%) had some form of tissue loss, 10.0 million patients (82%) did not. The 1-year crude amputation rate (major and minor) was 6.4% in patients with tissue loss, and 0.4% in patients without tissue loss. Among patients with tissue loss, the 1-year any amputation rate varied from 0.89% for patients with lymphadenitis to 26% for patients with gangrene. The 1-year amputation risk varied from two-fold for patients with lymphadenitis (adjusted hazard ratio, 1.96; 95% confidence interval, 1.43-2.69) to 29-fold for patients with gangrene (adjusted hazard ratio, 28.7; 95% confidence interval, 28.1-29.3), compared with patients without tissue loss. No other demographic variable including age, sex, race, or region incurred a hazard ratio for 1- or 5-year amputation risk higher than the least severe tissue loss category. Results were similar across minor and major amputation, and 1- and 5-year amputation outcomes. At a regional level, higher DM/PAD rates were inversely correlated with risk-adjusted 5-year amputation rates (R2 = 0.43).
CONCLUSIONS: Among 12 million patients with DM/PAD, the most significant predictor of amputation was the presence and extent of tissue loss, with an association greater in effect size than any other factor studied. Tissue loss could be used in awareness campaigns as a simple marker of high-risk patients. Patients with any type of tissue loss require expedited wound care, revascularization as appropriate, and infection management to avoid amputation. Establishing systems of care to provide these interventions in regions with high amputation rates may prove beneficial for these populations.
METHODS: Applying International Classification of Diseases (ICD)-9 and ICD-10 codes to Medicare claims data (2007-2019), we identified all patients with continuous fee-for-service Medicare coverage diagnosed with DM/PAD. Eight tissue loss categories were established using ICD-9 and ICD-10 diagnosis codes, ranging from lymphadenitis (least severe) to gangrene (most severe). We created a Cox proportional hazards model to quantify associations between tissue loss type and 1- and 5-year amputation risk, adjusting for age, race/ethnicity, sex, rurality, income, comorbidities, and preventive factors. Regional variation in DM/PAD rates and risk-adjusted amputation rates was examined at the hospital referral region level.
RESULTS: We identified 12,257,174 patients with DM/PAD (48% male, 76% White, 10% prior myocardial infarction, 30% chronic kidney disease). Although 2.2 million patients (18%) had some form of tissue loss, 10.0 million patients (82%) did not. The 1-year crude amputation rate (major and minor) was 6.4% in patients with tissue loss, and 0.4% in patients without tissue loss. Among patients with tissue loss, the 1-year any amputation rate varied from 0.89% for patients with lymphadenitis to 26% for patients with gangrene. The 1-year amputation risk varied from two-fold for patients with lymphadenitis (adjusted hazard ratio, 1.96; 95% confidence interval, 1.43-2.69) to 29-fold for patients with gangrene (adjusted hazard ratio, 28.7; 95% confidence interval, 28.1-29.3), compared with patients without tissue loss. No other demographic variable including age, sex, race, or region incurred a hazard ratio for 1- or 5-year amputation risk higher than the least severe tissue loss category. Results were similar across minor and major amputation, and 1- and 5-year amputation outcomes. At a regional level, higher DM/PAD rates were inversely correlated with risk-adjusted 5-year amputation rates (R2 = 0.43).
CONCLUSIONS: Among 12 million patients with DM/PAD, the most significant predictor of amputation was the presence and extent of tissue loss, with an association greater in effect size than any other factor studied. Tissue loss could be used in awareness campaigns as a simple marker of high-risk patients. Patients with any type of tissue loss require expedited wound care, revascularization as appropriate, and infection management to avoid amputation. Establishing systems of care to provide these interventions in regions with high amputation rates may prove beneficial for these populations.
摘要：
目的：先前的研究已经描述了伴随糖尿病和外周动脉疾病（DM/PAD）的患者与截肢相关的危险因素。然而,组织丢失类型的严重程度和程度与截肢风险之间的关联仍未得到很好的描述.我们旨在量化不同组织丢失类型在DM/PAD患者截肢风险中的作用。在人口统计学的背景下，预防性,和社会经济因素。
方法：将ICD-9和ICD-10代码应用于Medicare索赔数据（2007-2019），我们确定了所有诊断为DM/PAD的连续按服务付费Medicare承保的患者.使用ICD-9和ICD-10诊断代码建立了八个组织损失类别，范围从淋巴结炎（最不严重）到坏疽（最严重）。我们创建了一个Cox比例风险模型来量化组织损失类型与一年和五年截肢风险之间的关联，调整年龄，种族/民族,性别,rurality,收入,合并症,和预防因素。在医院转诊地区（HRR）水平检查了DM/PAD率和风险调整后的截肢率的区域差异。
结果：我们确定了12,257,174名DM/PAD患者（48％为男性，76%白色，10%以前的心肌梗塞，30%慢性肾脏病)。虽然220万患者（18％）有某种形式的组织损失，10.0万患者（82%）没有。组织丢失患者的一年粗截肢率（主要和次要）为6.4％，而无组织丢失的患者为0.4%。在组织丢失的患者中，一年的截肢率从淋巴结炎患者的0.89%到坏疽患者的26%不等。一年截肢风险从淋巴结炎患者的两倍（aHR1.96，95CI1.43-2.69）到坏疽患者的29倍（aHR28.7，95CI28.1-29.3），与没有组织损失的患者相比。没有其他人口统计学变量，包括年龄，性别,种族,1年或5年截肢风险高于最不严重的组织损失类别。小截肢和大截肢的结果相似，以及1年和5年截肢结果。在区域一级,较高的DM/PAD比率与经风险校正的5年截肢率呈负相关(R2=0.43).
结论：在1200万DM/PAD患者中，截肢最重要的预测指标是组织丢失的存在和程度，效果大小比研究的任何其他因素都大。组织损失可作为高风险患者的简单标记用于提高认识运动。任何类型的组织损失的患者都需要快速伤口护理，适当的血运重建，和感染管理，以避免截肢。在截肢率高的地区建立护理系统以提供这些干预措施可能对这些人群有益。
方法：将ICD-9和ICD-10代码应用于Medicare索赔数据（2007-2019），我们确定了所有诊断为DM/PAD的连续按服务付费Medicare承保的患者.使用ICD-9和ICD-10诊断代码建立了八个组织损失类别，范围从淋巴结炎（最不严重）到坏疽（最严重）。我们创建了一个Cox比例风险模型来量化组织损失类型与一年和五年截肢风险之间的关联，调整年龄，种族/民族,性别,rurality,收入,合并症,和预防因素。在医院转诊地区（HRR）水平检查了DM/PAD率和风险调整后的截肢率的区域差异。
结果：我们确定了12,257,174名DM/PAD患者（48％为男性，76%白色，10%以前的心肌梗塞，30%慢性肾脏病)。虽然220万患者（18％）有某种形式的组织损失，10.0万患者（82%）没有。组织丢失患者的一年粗截肢率（主要和次要）为6.4％，而无组织丢失的患者为0.4%。在组织丢失的患者中，一年的截肢率从淋巴结炎患者的0.89%到坏疽患者的26%不等。一年截肢风险从淋巴结炎患者的两倍（aHR1.96，95CI1.43-2.69）到坏疽患者的29倍（aHR28.7，95CI28.1-29.3），与没有组织损失的患者相比。没有其他人口统计学变量，包括年龄，性别,种族,1年或5年截肢风险高于最不严重的组织损失类别。小截肢和大截肢的结果相似，以及1年和5年截肢结果。在区域一级,较高的DM/PAD比率与经风险校正的5年截肢率呈负相关(R2=0.43).
结论：在1200万DM/PAD患者中，截肢最重要的预测指标是组织丢失的存在和程度，效果大小比研究的任何其他因素都大。组织损失可作为高风险患者的简单标记用于提高认识运动。任何类型的组织损失的患者都需要快速伤口护理，适当的血运重建，和感染管理，以避免截肢。在截肢率高的地区建立护理系统以提供这些干预措施可能对这些人群有益。
