Comparison of SAPS 3 performance in patients with and without solid tumor admitted to an intensive care unit in Brazil: a retrospective cohort study

ABSTRACT Objective: To compare the performance of the Simplified Acute Physiology Score 3 (SAPS 3) in patients with and without solid cancer who were admitted to the intensive care unit of a comprehensive oncological hospital in Brazil. Methods: We performed a retrospective cohort analysis of our administrative database of the first admission of adult patients to the intensive care unit from 2012 to 2016. The patients were categorized according to the presence of solid cancer. We evaluated discrimination using the area under the Receiver Operating Characteristic curve (AUROC) and calibration using the calibration belt approach. Results: We included 7,254 patients (41.5% had cancer, and 12.1% died during hospitalization). Oncological patients had higher hospital mortality than nononcological patients (14.1% versus 10.6%, respectively; p < 0.001). SAPS 3 discrimination was better for oncological patients (AUROC = 0.85) than for nononcological patients (AUROC = 0.79) (p < 0.001). After we applied the calibration belt in oncological patients, the SAPS 3 matched the average observed rates with a confidence level of 95%. In nononcological patients, the SAPS 3 overestimated mortality in those with a low-middle risk. Calibration was affected by the time period only for nononcological patients. Conclusion: SAPS 3 performed differently between oncological and nononcological patients in our single-center cohort, and variation over time (mainly calibration) was observed. This finding should be taken into account when evaluating severity-of-illness score performance.

摘要 目的：对比巴西某综合肿瘤医院重症监护病房（ICU）收治的伴与不伴实体瘤患者的简化急性生理学评分3（Simplified Acute Physiology Score 3, SAPS 3）性能表现。方法：对2012年至2016年本院成年患者首次入住ICU的管理数据库开展回顾性队列分析，依据是否存在实体瘤对患者进行分组。采用受试者工作特征曲线下面积（AUROC）评估模型区分度，采用校准带法评估校准度。结果：本研究共纳入7254例患者，其中41.5%罹患实体瘤，12.1%的患者住院期间死亡。肿瘤患者住院病死率高于非肿瘤患者（分别为14.1%与10.6%，p<0.001）。SAPS 3对肿瘤患者的区分度优于非肿瘤患者（AUROC分别为0.85与0.79，p<0.001）。针对肿瘤患者应用校准带法后，SAPS 3预测的平均病死率与实际观测值在95%置信水平下相符。针对非肿瘤患者，SAPS 3高估了中低危人群的病死率。仅在非肿瘤患者中，校准度受收治时间段的影响。结论：本单中心队列研究显示，SAPS 3在肿瘤与非肿瘤患者中的表现存在差异，且随时间推移（主要体现在校准度方面）存在变化。该发现可为重症病情严重程度评分的性能评估提供参考依据。