Poncet Antoine, Perneger Thomas V, Merlani Paolo, Capuzzo Maurizia, Combescure Christophe
Clinical Research Center, Faculty of Medicine, University of Geneva, Geneva 4, 1211, Geneva, Switzerland.
Division of clinical epidemiology, Department of health and community medicine, University Hospitals of Geneva, Rue Gabrielle Perret-Gentil 4, 1211, Geneva, Switzerland.
Crit Care. 2017 Apr 4;21(1):85. doi: 10.1186/s13054-017-1673-6.
The aim of the Simplified Acute Physiology Score (SAPS) II and SAPS 3 is to predict the mortality of patients admitted to intensive care units (ICUs). Previous studies have suggested that the calibration of these scores may vary across countries, centers, and/or characteristics of patients. In the present study, we aimed to assess determinants of the calibration of these scores.
We assessed the calibration of the SAPS II and SAPS 3 scores among 5266 patients admitted to ICUs during a 4-week period at 120 centers in 17 European countries. We obtained calibration curves, Brier scores, and standardized mortality ratios. Points attributed to SAPS items were reevaluated and compared with those of the original scores. Finally, we tested associations between the calibration and center characteristics.
The mortality was overestimated by both scores: The standardized mortality ratios were 0.75 (95% CI 0.71-0.79) for the SAPS II score and 0.91 (95% CI 0.86-0.96) for the SAPS 3 score. This overestimation was partially explained by changes in associations between some items of the scores and mortality, especially the heart rate, Glasgow Coma Scale score, and diagnosis of AIDS for SAPS II. The calibration of both scores was better in countries with low health expenditures. The between-center variability in calibration curves was much greater than expected by chance.
Both scores overestimate current mortality among European ICU patients. The magnitude of the miscalibration of SAPS II and SAPS 3 scores depends not only on patient characteristics but also on center characteristics. Furthermore, much between-center variability in calibration remains unexplained by these factors.
ClinicalTrials.gov identifier: NCT01422070 . Registered 19 August 2011.
简化急性生理学评分（SAPS）II和SAPS 3的目的是预测入住重症监护病房（ICU）患者的死亡率。先前的研究表明，这些评分的校准可能因国家、中心和/或患者特征而异。在本研究中，我们旨在评估这些评分校准的决定因素。
我们在17个欧洲国家的120个中心，对4周内入住ICU的5266例患者的SAPS II和SAPS 3评分的校准情况进行了评估。我们获得了校准曲线、Brier评分和标准化死亡率。重新评估了SAPS项目的得分，并与原始评分进行比较。最后，我们测试了校准与中心特征之间的关联。
两个评分均高估了死亡率：SAPS II评分的标准化死亡率为0.75（95%CI 0.71 - 0.79），SAPS 3评分为0.91（95%CI 0.86 - 0.96）。这种高估部分是由于评分的某些项目与死亡率之间的关联变化，特别是SAPS II的心率、格拉斯哥昏迷量表评分和艾滋病诊断。在卫生支出较低的国家，两个评分的校准情况较好。校准曲线的中心间变异性远大于偶然预期。
两个评分均高估了欧洲ICU患者目前的死亡率。SAPS II和SAPS 3评分校准错误的程度不仅取决于患者特征，还取决于中心特征。此外，这些因素仍无法解释校准中很大一部分的中心间变异性。
ClinicalTrials.gov标识符：NCT01422070。于2011年8月19日注册。
