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Insurance type and sepsis-associated hospitalizations and sepsis-associated mortality among US adults: A retrospective cohort study

James M O'Brien1*, Bo Lu2, Naeem A Ali1, Deborah A Levine23, Scott K Aberegg1 and Stanley Lemeshow2

Author Affiliations

1 Department of Internal Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Center for Critical Care, The Ohio State University Medical Center, 201 Davis HLRI, Columbus, OH 43221, USA

2 College of Public Health, The Ohio State University, 320 West 10th Avenue, B-110 Starling Loving Hall, Columbus, OH 43221, USA

3 Department of Medicine, Division of General Medicine, University of Michigan, 300 North Ingalls, 7C27, Ann Arbor, MI 48109, USA

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Critical Care 2011, 15:R130  doi:10.1186/cc10243

Published: 23 May 2011



Socio-demographic and clinical factors associated with increased sepsis risk, including older age, non-white race and specific co-morbidities, are more common among patients with Medicare or Medicaid or no health insurance. We hypothesized that patients with Medicare and/or Medicaid or without health insurance have a higher risk of sepsis-associated hospitalization or sepsis-associated death than those with private health insurance.


We performed a retrospective cohort study of records from the 2003 Nationwide Inpatient Sample. We stratified the study cohort by Medicare age-qualification (18 to 64 and 65+ years old). We examined the association between insurance category and sepsis diagnosis and death among admissions involving sepsis. We used validated diagnostic codes to determine the presence of sepsis, co-morbidities and organ dysfunction and to provide risk-adjustment.


Among patients 18 to 64 years old, those with Medicaid (adjusted odds ratio (AOR) 1.50), Medicare (AOR 1.96), Medicaid + Medicare (AOR 2.22) and the uninsured (AOR 1.18) had significantly higher risk-adjusted odds of a sepsis-associated admission than those with private insurance (all P < 0.0001). Those with Medicaid (AOR 1.17, P < 0.001) and those without insurance (AOR 1.45, P < 0.001) also had significantly higher adjusted odds of sepsis-associated hospital mortality than those with private insurance. Among those 65+ years old, those with Medicaid (AOR 1.43), Medicare alone (AOR 1.13) or Medicaid + Medicare (AOR 1.62) had significantly higher risk-adjusted odds of sepsis-associated admission than those with private insurance and Medicare (all P < 0.0001). Among sepsis patients 65+, uninsured patients had significantly higher risk-adjusted odds (AOR 1.45, P = 0.0048) and those with Medicare alone had significantly lower risk-adjusted odds (AOR 0.92, P = 0.0072) of hospital mortality than those with private insurance and Medicare. Lack of health insurance remained associated with sepsis-associated mortality after stratification of hospitals into quartiles based on rates of sepsis-associated admissions or mortality in both age strata.


Risks of sepsis-associated hospitalization and sepsis-associated death vary by insurance. These increased risks were not fully explained by the available socio-demographic factors, co-morbidities or hospital rates of sepsis-related admissions or deaths.