Data mining to evaluate mortality after amputation surgery

Abstract Background The objective of amputation and disarticulation is to improve health. However, these treatments are associated with significant mortality rates that vary in relation to risk factors. Objective To identify associations between determinants of postoperative mortality after amputation surgery. Methods Case-control study (death vs. no death) considering data from 173 patients who underwent amputation surgery at a public hospital in Santa Catarina state, Brazil. These data were analyzed using a data mining approach to discover association rules and epidemiologic association metrics. Results The main determinants were age > 60 years (odds ratio (OR) = 3.0), female sex (OR = 2.0), low education, hypertension (OR = 3.0), diabetes (OR = 1.6), and smoking (OR = 1.8). Among patients aged 60-69 years, 87.9% survived to discharge from hospital. The exceptions occurred when patients in this age range had peripheral vascular disease. The same was true when age was > 70 years, among whom diagnoses of embolism and thrombosis of arteries of the lower extremities were the exception factors (associated with death). The most common pathologies associated with death were vascular disease (47.0%) and diabetes (29.4%), heart disease (relative risk = 11.4), renal disease (OR = 10.4), and lung disease (OR = 5.2). Proximal surgeries were more strongly associated with death than distal ones. Among the deaths, 76.0% had been given spinal anesthesia and 24.0% general anesthesia. Conclusion Data mining enabled identification of associations between death and a variety of different variables and diagnostic hypotheses; for example, age > 70 years and diagnosis of embolism and thrombosis of arteries of the lower extremities.摘要 背景 截肢与关节离断术的治疗目标为改善患者健康状况。然而此类手术与较高的死亡率相关，且死亡率随危险因素的不同而存在差异。 研究目的 旨在明确截肢术后患者术后死亡的相关影响因素间的关联。 研究方法 本研究为病例对照研究（死亡组vs存活组），纳入巴西圣卡塔琳娜州某公立医院收治的173例接受截肢手术的患者数据。采用数据挖掘方法对上述数据进行分析，以挖掘关联规则及流行病学关联指标。 研究结果 主要影响因素包括年龄＞60岁（比值比（OR）=3.0）、女性性别（OR=2.0）、低文化程度、高血压（OR=3.0）、糖尿病（OR=1.6）以及吸烟（OR=1.8）。在60~69岁的患者中，87.9%可存活至出院，但当该年龄段患者合并外周血管疾病时，这一存活率例外。年龄＞70岁的患者亦呈现相同规律，但若此类患者被诊断为下肢动脉栓塞与血栓形成，则为与死亡相关的例外危险因素。与死亡相关的最常见病理状况为血管疾病（47.0%）与糖尿病（29.4%），此外还包括心脏病（相对危险度（RR）=11.4）、肾脏疾病（OR=10.4）及肺部疾病（OR=5.2）。近端截肢手术较远端截肢手术与死亡的关联性更强。在死亡病例中，76.0%接受了脊髓麻醉，24.0%接受了全身麻醉。 研究结论 数据挖掘技术助力明确了患者死亡与多种变量及诊断假说间的关联，例如年龄＞70岁合并下肢动脉栓塞与血栓形成的患者。