Supplementary Material for: Risk Factors for Development of Acute Kidney Injury in COVID-19 Patients: A Retrospective Observational Cohort Study

<b><i>Introduction:</i></b> Acute kidney injury (AKI) in coronavirus infection disease (COVID-19) is associated with disease severity. We aimed to evaluate risk factors associated with AKI beyond COVID-19 severity. <b><i>Methods:</i></b> A retrospective observational study of COVID-19 patients admitted to a tertiary hospital in Singapore. Logistic regression was used to evaluate associations between risk factors and AKI (based on Kidney Disease Improving Global Outcomes criteria). Dominance analysis was performed to evaluate the relative importance of individual factors. <b><i>Results:</i></b> Seven hundred seven patients were included. Median age was 46 years (interquartile range [IQR]: 29–57) and 57% were male with few comorbidities (93%, Charlson Comorbidity Index [CCI] &lt;1). AKI occurred in 57 patients (8.1%); 39 were in AKI stage 1 (68%), 9 in stage 2 (16%), and 9 in stage 3 (16%). Older age (adjusted odds ratio [aOR] 1.04; 95% confidence interval [CI]: 1.01–1.07), baseline use of angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) (aOR 2.86; 95% CI: 1.20–6.83), exposure to vancomycin (aOR 5.84; 95% CI: 2.10–16.19), use of nonsteroidal anti-inflammatory drugs (NSAIDs) (aOR 3.04; 95% CI: 1.15–8.05), and severe COVID-19 with hypoxia (aOR 13.94; 95% CI: 6.07–31.98) were associated with AKI in the multivariable logistic regression model. The 3 highest ranked predictors were severe COVID-19 with hypoxia, vancomycin exposure, and age, accounting for 79.6% of the predicted variance (41.6, 23.1, and 14.9%, respectively) on dominance analysis. <b><i>Conclusion:</i></b> Severe COVID-19 is independently associated with increased risk of AKI beyond premorbid conditions and age. Appropriate avoidance of vancomycin and NSAIDs are potentially modifiable means to prevent AKI in patients with COVID-19.

引言：新型冠状病毒肺炎（coronavirus disease 2019, COVID-19）相关急性肾损伤（acute kidney injury, AKI）与疾病严重程度密切相关。本研究旨在探究除疾病严重程度外，与AKI相关的危险因素。
方法：本研究为回顾性观察性研究，纳入新加坡某三级医院收治的COVID-19患者。采用logistic回归分析评估各危险因素与AKI的相关性（AKI诊断标准参照改善全球肾脏病预后组织（Kidney Disease: Improving Global Outcomes, KDIGO）指南），并通过优势分析评估各因素的相对重要性。
结果：本研究共纳入707例患者，年龄中位数为46岁（四分位间距[IQR]：29~57），男性占比57%，多数患者合并症较少（93%患者查尔森合并症指数[Charlson Comorbidity Index, CCI]＜1）。共计57例患者发生AKI（占比8.1%），其中39例为AKI 1期（68%）、9例为2期（16%）、9例为3期（16%）。多因素logistic回归分析结果显示，年龄增长（校正比值比[aOR] 1.04；95%置信区间[CI]：1.01~1.07）、基线使用血管紧张素转换酶抑制剂（angiotensin-converting enzyme inhibitor, ACE-I）或血管紧张素Ⅱ受体拮抗剂（angiotensin receptor blocker, ARB）（aOR 2.86；95% CI：1.20~6.83）、暴露于万古霉素（aOR 5.84；95% CI：2.10~16.19）、使用非甾体抗炎药（nonsteroidal anti-inflammatory drugs, NSAIDs）（aOR 3.04；95% CI：1.15~8.05）以及合并缺氧的重症COVID-19（aOR 13.94；95% CI：6.07~31.98）均与AKI发生显著相关。优势分析结果显示，排名前三的预测因素依次为合并缺氧的重症COVID-19、万古霉素暴露及年龄，三者共解释了79.6%的预测变异（分别为41.6%、23.1%及14.9%）。
结论：除基础疾病状态与年龄外，重症COVID-19与AKI风险升高存在独立相关性。合理规避万古霉素与非甾体抗炎药的使用，或可成为预防COVID-19患者发生AKI的可干预措施。