Optimizing Risk-Adjustment for Measuring ICU Quality

这个职业发展奖项的目的是制定一个研究和培训计划，使Glance博士成为健康结果研究领域的独立医师调查员。本提案的重点将是研究在大型多机构数据库中使用风险调整模型对重症监护病房（ICU）绩效进行基准测试的可行性。粗死亡率不能用于比较ICU，因为它们不能解释ICU患者群体之间疾病严重程度的差异。然而，标准化死亡率（SMR），定义为观察死亡率（OMR）与预期死亡率（EMR）之比，确实考虑了icu之间患者病例组合的差异，因此可用于比较单个icu的表现。EMR是通过使用ICU评分系统计算特定人群中患者的预测死亡率而获得的。使用严重程度调整的结果指标，如SMR，可以识别低和高性能icu。这种方法的一个潜在问题是，一般的严重程度评分系统在如何使用严重程度调整后的结果指标对个别医院进行排名方面存在分歧。ICU评分系统很可能也会以同样的方式运行；具体目标#1将检验APACHE 11（急性生理和慢性健康评估）、SAPS 11（简化急性生理评分）和MPM II（死亡概率模型）的这一假设。不同的评分系统在质量异常值的身份上存在分歧，这一发现引发了对使用严重程度调整结果测量的基准测试工作的表面有效性的怀疑。验证研究表明，ICU评分系统在大多数数据集（用于开发原始模型的数据集除外）中进行评估时表现不佳。因此，毫不奇怪的是，严重程度调整后的结果措施不一致的医院质量时，他们所依据的评分系统不准确。但是，预测模型可以针对数据集进行定制，以便更准确地预测该数据集中的结果。具体目标#2将检验这样一个命题：在将评分系统定制为ICU数据库后，ICU评分系统更有可能就质量异常值的身份达成一致，该数据库由正在对其性能进行基准测试的ICU组成。

The purpose of this career development award is to develop a research and training program that will enable Dr. Glance to become an independent physician investigator in the field of health outcomes research. The focus of this proposal will be to examine the feasibility of using risk-adjustment models for benchmarking Intensive Care Unit (ICU) performance in a large multi-institutional database. Crude mortality rates cannot be used to compare ICUs because they do not account for differences in the severity of disease between ICU patient populations. However, the Standardized Mortality Ratio (SMR), defined as the ratio of the observed mortality rate (OMR) to the expected mortality rate (EMR), does account for differences in patient case mix between ICUs, and can therefore be used to compare the performance of individual ICUs. The EMR is obtained by calculating the predicted mortality of the patients in a specific population using an ICU scoring system. Using severity-adjusted outcome measures like the SMR, low- and high-performance ICUs can be identified. A potential problem with this approach is the finding that general severity scoring systems disagree on how to rank individual hospitals using severity-adjusted outcome measures. It is likely that ICU scoring systems will behave in the same manner; Specific Aim #1 will examine this hypothesis for APACHE 11 (Acute Physiology and Chronic Health Evaluation), SAPS 11 (Simplified Acute Physiology Score) and MPM II (Mortality Probability Model). A finding that different scoring systems disagree on the identity of quality outliers raises doubt regarding the face validity of benchmarking efforts using severity-adjusted outcome measures. Validation studies have demonstrated that ICU scoring systems perform poorly when evaluated in most data sets (other than the one used to develop the original model). Therefore, it not surprising that severity-adjusted outcome measures do not agree on hospital quality when the scoring systems on which they are based are not accurate. However, predictive models can be customized to a data set so that they will more accurately predict outcomes within that data set. Specific Aim #2 will examine the proposition that ICU scoring systems are more likely to agree on the identity of quality outliers after the scoring systems have been customized to the ICU database made up of the ICUs whose performance is being benchmarked.