Association between critical care physician management and patient mortality in the intensive care unit

Background: Critically ill patients admitted to intensive care units (ICUs) are thought to gain an added survival benefit from management by critical care physicians, but evidence of this benefit is scant. Objective: To examine the association between hospital mortality in critically ill patients and management by critical care physicians. Design: Retrospective analysis of a large, prospectively collected database of critically ill patients. Setting: 123 ICUs in 100 U. S. hospitals. Patients: 101 832 critically ill adults. Measurements: Through use of a random-effects logistic regression, investigators compared hospital mortality between patients cared for entirely by critical care physicians and patients cared for entirely by non-critical care physicians. An expanded Simplified Acute Physiology Score was used to adjust for severity of illness, and a propensity score was used to adjust for differences in the probability of selective referral of patients to critical care physicians. Results: Patients who received critical care management (CCM) were generally sicker, received more procedures, and had higher hospital mortality rates than those who did not receive CCM. After adjustment for severity of illness and propensity score, hospital mortality rates were higher for patients who received CCM than for those who did not. The difference in adjusted hospital mortality rates was less for patients who were sicker and who were predicted by propensity score to receive CCM. Limitation: Residual confounders for illness severity and selection biases for CCM might exist that were inadequately assessed or recognized. Conclusion: In a large sample of ICU patients in the United States, the odds of hospital mortality were higher for patients managed by critical care physicians than those who were not. Additional studies are needed to further evaluate these results and clarify the mechanisms by which they might occur.