Kuzniewicz Michael W, Vasilevskis Eduard E, Lane Rondall, Dean Mitzi L, Trivedi Nisha G, Rennie Deborah J, Clay Ted, Kotler Pamela L, Dudley R Adams
Institute for Health Policy Studies, University of California, San Francisco, San Francisco, CA.
Institute for Health Policy Studies, University of California, San Francisco, San Francisco, CA.
Chest. 2008 Jun;133(6):1319-1327. doi: 10.1378/chest.07-3061. Epub 2008 Apr 10.
Federal and state agencies are considering ICU performance assessment and public reporting; however, an accurate method for measuring performance must be selected. In this study, we determine whether a substantial variation in ICU mortality performance still exists in modern ICUs, and compare the predictive accuracy, reliability, and data burden of existing ICU risk-adjustment models.
A retrospective chart review of 11,300 ICU patients from 35 California hospitals from 2001 to 2004 was performed. We calculated standardized mortality ratios (SMRs) for each hospital using the mortality probability model III (MPM(0) III), the simplified acute physiology score (SAPS) II, and the acute physiology and chronic health evaluation (APACHE) IV risk-adjustment models. We compared discrimination, calibration, data reliability, and abstraction time for the models.
Regardless of the model used, there was a large variation in SMRs among the ICUs studied. The discrimination and calibration were adequate for all risk-adjustment models. APACHE IV had the best discrimination (area under the receiver operating characteristic curve [AUC], 0.892) compared to MPM(0) III (AUC, 0.809), and SAPS II (AUC, 0.873; p < 0.001). The models differed substantially in data abstraction times, as follows: MPM(0)III, 11.1 min (95% confidence interval [CI], 8.7 to 13.4); SAPS II, 19.6 min (95% CI, 17.0 to 22.2); and APACHE IV, 37.3 min (95% CI, 28.0 to 46.6).
We found substantial variation in the ICU risk-adjusted mortality rates that persisted regardless of the risk-adjustment model. With unlimited resources, the APACHE IV model offers the best predictive accuracy. If constrained by cost and manual data collection, the MPM(0) III model offers a viable alternative without a substantial loss in accuracy.
联邦和州机构正在考虑重症监护病房（ICU）绩效评估及公开报告；然而，必须选择一种准确的绩效衡量方法。在本研究中，我们确定现代ICU中ICU死亡率绩效是否仍存在显著差异，并比较现有ICU风险调整模型的预测准确性、可靠性和数据负担。
对2001年至2004年加利福尼亚州35家医院的11300例ICU患者进行回顾性病历审查。我们使用死亡率概率模型III（MPM(0) III）、简化急性生理学评分（SAPS）II和急性生理学与慢性健康评估（APACHE）IV风险调整模型计算每家医院的标准化死亡率（SMR）。我们比较了这些模型的区分度、校准度、数据可靠性和提取时间。
无论使用何种模型，在所研究的ICU之间，SMR存在很大差异。所有风险调整模型的区分度和校准度都足够。与MPM(0) III（曲线下面积[AUC]，0.809）和SAPS II（AUC，0.873；p < 0.001）相比，APACHE IV具有最佳区分度（AUC，0.892）。这些模型在数据提取时间上有很大差异，如下所示：MPM(0)III，11.1分钟（95%置信区间[CI]，8.7至13.4）；SAPS II，19.6分钟（95%CI，17.0至22.2）；APACHE IV，37.3分钟（95%CI，28.0至46.6）。
我们发现，无论风险调整模型如何，ICU风险调整死亡率都存在显著差异。在资源不受限的情况下，APACHE IV模型具有最佳预测准确性。如果受到成本和人工数据收集的限制，MPM(0) III模型提供了一个可行选择，而准确性不会有实质性损失。
