The association of lacking insurance with outcomes of severe sepsis: retrospective analysis of an administrative database*

Abstract

Objective: Patients with severe sepsis have high mortality that is improved by timely, often expensive, treatments. Patients without insurance are more likely to delay seeking care; they may also receive less intense care.

Design: We performed a retrospective analysis of administrative database-Healthcare Costs and Utilization Project's Nationwide Inpatient Sample-to test whether mortality is more likely among uninsured patients hospitalized for severe sepsis.

Patients: None.

Interventions: We used International Classification of Diseases-9th Revision, Clinical Modification, codes indicating sepsis and organ system failure to identify hospitalizations for severe sepsis among patients aged 18-64 between 2000 and 2008. We excluded patients with end-stage renal disease or solid organ transplants because very few are uninsured. We performed multivariate logistic regression modeling to examine the association of insurance status and in-hospital mortality, adjusted for patient and hospital characteristics. We performed subgroup analysis to examine whether the impact of insurance status varied by geographical region; by patient age, sex, or race; or by hospital characteristics such as teaching status, size, or ownership. We used similar methods to examine the impact of insurance status on the use of certain procedures, length of stay, and discharge destination.

Measurements and main results: There were 1,600,269 discharges with severe sepsis from 2000 through 2008 in the age group 18-64 years. Uninsured people, who accounted for 7.5% of admissions with severe sepsis, had higher adjusted odds of mortality (odds ratio, 1.43; 95% CI, 1.37-1.47) than privately insured people. The higher mortality in uninsured was present in all subgroups and was similar in each year from 2000 to 2008. After adjustment, uninsured individuals had a slightly shorter length of stay than insured people and were less likely to receive five of the six interventions we examined. They were also less likely to be discharged to skilled nursing facilities or with home healthcare after discharge.

Conclusions: Uninsured are more likely to die following admission for severe sepsis than patients with insurance, even after adjusting for potential confounders. This was not due to a hospital effect or demographic or clinical factors available in our administrative database. Further research should examine the mechanisms that lead to this association.

Figure 1

Comparison of uninsured versus private insurance in various subgroups. The graph shows odds ratio of mortality in severe sepsis adjusting for the other variables in Table 3.