RESUMEN
RATIONALE: One in three Americans under 65 years of age does not have health insurance during some portion of each year. Patients who are critically ill and lack health insurance may be at particularly high risk of morbidity and mortality due to the high cost of intensive care. OBJECTIVES: To systematically review the medical and nonmedical literature to determine whether differences in critical care access, delivery, and outcomes are associated with health insurance status. METHODS: Nine electronic databases (inception to 11 April 2008) were independently screened and abstracted in duplicate. MEASUREMENTS AND MAIN RESULTS: From 5,508 citations, 29 observational studies met eligibility criteria. Among the general U.S. population, patients who were uninsured were less likely to receive critical care services than those with insurance (odds ratio [OR], 0.56; 95% confidence interval [CI], 0.55-0.56). Once admitted to the intensive care unit, patients who were uninsured had 8.5% (95% CI, 6.0-11.1) fewer procedures, were more likely to experience hospital discharge delays (OR 4.51; 95% CI, 1.46-13.93), and were more likely to have life support withdrawn (OR 2.80; 95% CI, 1.12-7.02). Lack of insurance may confer an independent risk of death for patients who are critically ill (OR 1.16; 95% CI, 1.01-1.33). Patients in managed care systems had 14.3% (95% CI, 11.5-17.2) fewer procedures in intensive care, but were also less likely to receive "potentially ineffective" care. Differences in unmeasured confounding factors may contribute to these findings. CONCLUSIONS: Patients in the United States who are critically ill and do not have health insurance receive fewer critical care services and may experience worse clinical outcomes. Improving preexisting health care coverage, as opposed to solely delivering more critical care services, may be one mechanism to reduce such disparities.