Supplementary Material for: Superiority of Simplified Acute Physiologic Score II Compared with Acute Physiologic and Chronic Health Evaluation II and Sequential Organ Failure Assessment Scores for Predicting 48-Hour Mortality in Patients Receiving Continuous Kidney Replacement Therapy

Background: Predicting early mortality is important in patients undergoing continuous kidney replacement therapy (CKRT), especially in the first 48 h. This study aimed to determine the predictive performance of the Simplified Acute Physiologic Score (SAPS) II, the Acute Physiologic and Chronic Health Evaluation (APACHE) II, and the Sequential Organ Failure Assessment (SOFA) scores for early mortality in patients receiving CKRT. Methods: Data from patients with acute kidney injury receiving CKRT were consecutively and retrospectively obtained at a tertiary medical center between August 2017 and March 2021. The outcomes included 48-h and 7-day mortality. The scoring systems were evaluated via discrimination at the time of CKRT initiation (using area under the receiver operating characteristics curve [AUROC]) and calibration (via Hosmer-Lemeshow goodness-of-fit C statistics). Results: Among eligible 652 patients, 95 (14.6%) and 212 (32.5%) died within 48 h and within 7 days, respectively. The AUROC for SAPS II (0.71, 95% confidence interval [CI]: 0.65–0.77, p = 0.016 vs. APACHE II score, p = 0.044 vs. SOFA score) was significantly higher than that of the APACHE II (0.66, 95% CI: 0.60–0.72) and SOFA scores (0.66, 95% CI: 0.60–0.72) for 48-h mortality. However, no significant differences in the AUROCs for SAPS II, APACHE II, and SOFA scores for 7-day mortality were observed. The calibration of the SAPS II for 48-h and 7-day mortality was adequate (p = 0.507 and p = 0.141, respectively). Conclusions: The predictive performance of SAPS II for mortality within the first 48 h was superior to that of the APACHE II and SOFA scores in patients with acute kidney injury receiving CKRT.

背景：早期死亡预测对于接受连续肾脏替代疗法（continuous kidney replacement therapy, CKRT）的患者具有重要临床价值，尤其在治疗初始的48小时内。本研究旨在明确简化急性生理学评分（Simplified Acute Physiologic Score, SAPS）II、急性生理学与慢性健康状况评分系统（Acute Physiologic and Chronic Health Evaluation, APACHE）II以及序贯器官衰竭评估（Sequential Organ Failure Assessment, SOFA）评分对接受CKRT患者早期死亡的预测效能。
方法：本研究于2017年8月至2021年3月期间，在某三级医疗中心回顾性连续纳入接受CKRT的急性肾损伤患者并收集其临床数据。研究结局指标包括48小时死亡率与7天死亡率。分别于CKRT启动时，通过鉴别能力（采用受试者工作特征曲线下面积[AUROC]）与校准能力（采用Hosmer-Lemeshow拟合优度C统计量）对上述评分系统进行评估。
结果：最终纳入符合标准的652例患者中，分别有95例（14.6%）和212例（32.5%）在48小时内及7天内死亡。针对48小时死亡率，SAPS II评分的AUROC为0.71（95%置信区间[CI]：0.65~0.77），显著高于APACHE II评分（0.66，95%CI：0.60~0.72）与SOFA评分（0.66，95%CI：0.60~0.72），组间比较差异分别具有统计学意义（p=0.016、p=0.044）。然而，针对7天死亡率，SAPS II、APACHE II与SOFA评分的AUROC未见显著差异。SAPS II评分对48小时及7天死亡率的校准性能良好（分别对应p=0.507与p=0.141）。
结论：在接受CKRT的急性肾损伤患者中，SAPS II评分对初始48小时内死亡率的预测效能优于APACHE II与SOFA评分。