How does lack of insurance affect use of intensive care? A population-based study*

Abstract

One in six Americans aged <65 yrs are without health insurance. Although lack of insurance is associated with reduced access to many health services, the relationship between lack of insurance and use of intensive care services is unclear. We sought to compare the use of intensive care by insured and uninsured populations. Retrospective population-based cross-sectional study of five U.S. states (Florida, Massachusetts, New Jersey, New York, and Virginia), analyzing use of hospital and intensive care unit (ICU) services by all residents of these states <65 yrs of age. Data sources included the five 1999 state hospital discharge databases and the 2000 U.S. Census Bureau Current Population Survey. Nonfederal hospitals in the five states (all hospitalizations in these during 1999). None. There were 39.3 million and 7.8 million individuals aged 0-64 yrs with and without insurance, respectively, in the five-state sample. The uninsured population was far less likely to be hospitalized (odds ratio [OR], 0.458; 95% confidence interval [CI], 0.456-0.460; p < .001) and to be admitted to the ICU (OR, 0.581, 95% CI: 0.576-0.587, p < .001). Differences persisted irrespective of age, gender, ethnicity, or reason for admission. Among those hospitalized, the uninsured were more likely to receive intensive care (OR, 1.24; 95% CI, 1.22-1.25; p < .01). Hospital mortality rates for patients admitted to the ICU ranged by age from 4.0% to 6.9% for the uninsured and from 2.7% to 5.5% for the insured (OR, 1.12-1.54; p < .01). Americans without insurance use ICU services less often than those with insurance, primarily because of decreased likelihood of hospital admission in the first place. Outcome is worse for those who are admitted to the ICU, possibly because they are sicker when they seek care.