Green J, Wintfeld N, Sharkey P, Passman L J
Department of Health Policy Research, New York University Medical Center/New York University School of Medicine 10016.
JAMA. 1990 Jan 12;263(2):241-6.
Each year, the Health Care Financing Administration (HCFA) releases a report comparing hospital mortality rates with predicted rates. Some argue that the HCFA's prediction model does not adequately account for patient severity. We tested this hypothesis by comparing the HCFA's model (replicated as closely as we could) to a second that added a severity measure (the Stage of Principal Diagnosis at Admission, a subscale of the Severity of Illness Index). In our simulation, the HCFA's model had very limited capacity to predict mortality (average R2, 2.5%). Patients grouped according to admission severity had markedly different mortality rates, which the HCFA's model's predictions could not differentiate. The HCFA model also failed to predict large differences in mortality between hospitals with low- and high-severity admissions. Adding severity to the HCFA's model yielded more than an eightfold increase in the R2, to 21.5%, and reduced instances of higher than expected hospital mortality to chance levels. These findings suggest that the HCFA's mortality release needs to be made much more sensitive to admission severity before it can be used to make valid inferences about the quality or effectiveness of hospital care.
每年，医疗保健财务管理局（HCFA）都会发布一份报告，比较医院的死亡率与预测死亡率。一些人认为，HCFA的预测模型没有充分考虑患者的病情严重程度。我们通过将HCFA的模型（尽可能精确地复制）与另一个加入了病情严重程度衡量指标（入院时主要诊断阶段，疾病严重程度指数的一个子量表）的模型进行比较，来检验这一假设。在我们的模拟中，HCFA的模型预测死亡率的能力非常有限（平均R2为2.5%）。根据入院时病情严重程度分组的患者死亡率有显著差异，但HCFA模型的预测无法区分这些差异。HCFA模型也未能预测低病情严重程度入院和高病情严重程度入院的医院之间死亡率的巨大差异。在HCFA模型中加入病情严重程度指标后，R2增加了八倍多，达到21.5%，并将高于预期的医院死亡率情况减少到随机水平。这些发现表明，在HCFA发布的死亡率报告能够用于对医院护理质量或效果做出有效推断之前，需要使其对入院时的病情严重程度更加敏感。
