Cardiac Division of Anesthesiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
Eur J Cardiothorac Surg. 2012 Feb;41(2):307-13. doi: 10.1016/j.ejcts.2011.06.015. Epub 2011 Dec 12.
The European System for Cardiac Operative Risk Evaluation (EuroSCORE) and the Cardiac Anesthesia Risk Evaluation (CARE) score are risk indices designed in the mid-1990 s to predict mortality after cardiac surgery. This study assesses their ability to provide risk-adjusted mortality in a contemporary cardiac surgical population.
The mortality probability was estimated with the additive and logistic EuroSCORE, and CARE score, for 3818 patients undergoing cardiac surgery at one institution between 1 April 2006 and 31 March 2009. Model discrimination was obtained using the area under the receiver operating characteristics (ROC) curve and calibration using the appropriate chi-square goodness-of-fit test. Recalibration of risk models was obtained by logistic calibration, when needed. Calculation of risk-adjusted mortality was performed for the institution and eight surgeons, using each model before and when needed, after recalibration.
The area under the ROC curve is 0.72 (95% confidence interval (CI): 0.71-0.74) with the additive EuroSCORE, 0.84 (95% CI: 0.83-0.85) with the logistic EuroSCORE, and 0.79 (95% CI: 0.78-0.81) with the CARE score. The additive and logistic EuroSCORE have poor calibration, predicting a hospital mortality of 6.24% and 7.72%, respectively, versus an observed mortality of 3.25% (P < 0.001). Consequently, the risk-adjusted mortality obtained with those models is significantly underestimated for the institution and all surgeons. The CARE score has good calibration, predicting a mortality of 3.38% (P = 0.50). The hospital risk-adjusted mortality with the recalibrated additive and logistic EuroSCORE and CARE score is 3.24% (95% CI: 3.05-3.43%), 3.25% (95% CI: 3.05-3.44%), and 3.12% (95% CI: 2.94-3.34%), respectively. The individual surgeons' risk-adjusted mortality is similar with the recalibrated EuroSCORE models and CARE score, identifying two surgeons with higher rates than the hospital average mortality.
The original additive and logistic EuroSCORE models significantly overestimate the risk of mortality after cardiac surgery. However, after recalibration both models provide reliable risk-adjusted mortality results. Despite its lower discrimination as compared with the logistic EuroSCORE, the CARE score remains calibrated a decade after its development. It is as robust as the recalibrated additive and logistic EuroSCORE to perform risk-adjusted mortality analysis.
欧洲心脏手术风险评估系统（EuroSCORE）和心脏麻醉风险评估（CARE）评分是 20 世纪 90 年代中期设计的预测心脏手术后死亡率的风险指数。本研究评估了它们在当代心脏外科人群中提供风险调整后死亡率的能力。
在一家机构于 2006 年 4 月 1 日至 2009 年 3 月 31 日期间对 3818 名接受心脏手术的患者进行了估计死亡率的加性和逻辑 EuroSCORE 和 CARE 评分。使用接受者操作特征曲线（ROC）下的面积（AUC）和适当的卡方拟合优度检验来获得模型的判别能力。在需要时，通过逻辑校准来重新校准风险模型。使用每个模型在机构和 8 位外科医生中进行风险调整后死亡率的计算，在重新校准之前和之后进行。
加性 EuroSCORE 的 AUC 为 0.72（95%置信区间（CI）：0.71-0.74），逻辑 EuroSCORE 的 AUC 为 0.84（95%CI：0.83-0.85），CARE 评分的 AUC 为 0.79（95%CI：0.78-0.81）。加性和逻辑 EuroSCORE 的校准效果不佳，分别预测医院死亡率为 6.24%和 7.72%，而观察到的死亡率为 3.25%（P<0.001）。因此，对于机构和所有外科医生来说，使用这些模型获得的风险调整后死亡率明显被低估。CARE 评分的校准效果良好，预测死亡率为 3.38%（P=0.50）。重新校准的加性和逻辑 EuroSCORE 和 CARE 评分的医院风险调整后死亡率分别为 3.24%（95%CI：3.05-3.43%）、3.25%（95%CI：3.05-3.44%）和 3.12%（95%CI：2.94-3.34%）。重新校准的 EuroSCORE 模型和 CARE 评分的个体外科医生风险调整后死亡率相似，确定了两名外科医生的死亡率高于医院平均死亡率。
原始的加性和逻辑 EuroSCORE 模型显著高估了心脏手术后的死亡率风险。然而，在重新校准后，这两个模型都提供了可靠的风险调整后死亡率结果。尽管与逻辑 EuroSCORE 相比，其判别能力较低，但 CARE 评分在开发十年后仍保持校准状态。它与重新校准的加性和逻辑 EuroSCORE 一样稳健，能够进行风险调整后死亡率分析。
