Supplementary Material for: Characteristics and prognostic factors of SARS-CoV-2 Omicron variant infection in hemodialysis patients: a single-center study in China

Introduction: This study aimed to evaluate the characteristics and prognostic factors for coronavirus disease 2019 (COVID-19) patients on maintenance hemodialysis (HD).
Methods: All admitted HD patients who were infected with severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) from December 1, 2022 to January 31, 2023 were included. Patients with pneumonia were further classified into the mild, moderate, severe and critical illness. Clinical symptoms, laboratory results, radiologic findings, treatment and clinical outcomes were collected. Independent risk factors for progression to critical disease, and in-hospital mortality were determined by the multivariate regression analysis. The receiver operating characteristic (ROC) analysis with the area under the curve (AUC) was used to evaluate the predictive performance of developing critical status and in-hospital mortality.
Results: A total of 182 COVID-19 patients with HD were included, with an average age of the 61.55 years. Out of the total, 84 (46.1%) patients did not have pneumonia and 98 (53.8%) patients had pneumonia. Among patients with pneumonia, 48 (49.0%) had moderate illness, 26 (26.5%) severe illness, and 24 (24.5%) critical illness, respectively. Elder age [HR (95% CI): 1.07 (1.01-1.13), P<0.01], increased levels of lactate dehydrogenase (LDH) [1.01 (1.003-1.01), P<0.01] and C-reactive protein (CRP) [1.01 (1.00-1.01), P=0.04] were risk factors for developing critical illness. Elder age [1.11 (1.03-1.19), P=0.01], increased procalcitonin (PCT) [1.07 (1.02-1.12), P=0.01], and LDH level [1.004 (1-1.01), P=0.03] were factors associated with increased risk of in-hospital mortality.
Conclusions: Age, CRP, PCT and LDH can be used to predict negative clinical outcomes for HD patients with COVID-19 pneumonia.

引言：本研究旨在评估接受维持性血液透析（maintenance hemodialysis, HD）的2019冠状病毒病（coronavirus disease 2019, COVID-19）患者的临床特征与预后影响因素。
方法：本研究纳入2022年12月1日至2023年1月31日期间收治的所有感染严重急性呼吸综合征冠状病毒2（severe acute respiratory syndrome coronavirus 2, SARS-CoV-2）的血液透析患者。合并肺炎的患者进一步分为轻症、中症、重症及危重症四个组别。研究收集了患者的临床症状、实验室检测结果、影像学表现、治疗方案及临床转归数据。采用多因素回归分析，明确患者进展为危重症及住院期间死亡的独立危险因素。通过受试者工作特征（receiver operating characteristic, ROC）分析及曲线下面积（area under the curve, AUC），评估模型对患者进展为危重症及住院期间死亡的预测效能。
结果：本研究共纳入182例合并COVID-19的血液透析患者，平均年龄为61.55岁。其中84例（46.1%）患者未合并肺炎，98例（53.8%）患者合并肺炎。在合并肺炎的患者中，48例（49.0%）为中症，26例（26.5%）为重症，24例（24.5%）为危重症。高龄[风险比（Hazard Ratio, HR）：1.07（95%置信区间（95% confidence interval, 95%CI）：1.01~1.13），P<0.01]、乳酸脱氢酶（lactate dehydrogenase, LDH）水平升高[1.01（1.003~1.01），P<0.01]及C反应蛋白（C-reactive protein, CRP）水平升高[1.01（1.00~1.01），P=0.04]为患者进展为危重症的独立危险因素。高龄[1.11（1.03~1.19），P=0.01]、降钙素原（procalcitonin, PCT）水平升高[1.07（1.02~1.12），P=0.01]及LDH水平升高[1.004（1~1.01），P=0.03]为与患者住院期间死亡风险升高相关的因素。
结论：年龄、CRP、PCT及LDH可用于预测合并COVID-19肺炎的血液透析患者的不良临床转归。