Association between Insurance Status and Admission Rate for Patients Evaluated in the Emergency Department

Authors


Washington University School of Medicine, Department of Medicine, Division of General Medical Sciences, 660 S. Euclid Ave., Campus Box 8005, St. Louis, MO 63110. Fax 314-454-5554; e-mail: jruger@im.wustl.edu.

Abstract

Objectives: To determine if differences exist in hospital and intensive care unit (ICU)/operating room admission rates based on health insurance status. Methods: This was a retrospective, cross-sectional study of data from hospital clinical and financial records for all 2001 emergency department (ED) visits (80,209) to an academic urban hospital. Hospital admission and intensive care unit (ICU)/operating room admissions were analyzed, controlling for triage acuity, primary complaint, diagnosis, diagnosis-related group (DRG) severity, and demographics. Multivariate logistic regression models identified factors associated with hospital admission for underinsured (self-pay and Medicaid) compared with other insured (private health maintenance organization, preferred provider organization, worker's compensation, and Medicare) patients. Results: Compared with the other insured group, underinsured patients were less likely, overall, to be admitted to the hospital (odds ratio [OR], 0.82; 95% CI = 0.76 to 0.90), controlling for all other factors studied. Subgroup analysis of common complaints showed underinsured patients with a chief complaint of abdominal pain (OR, 0.67; 95% CI = 0.55 to 0.80) or headache (OR, 0.61; 95% CI = 0.39 to 0.95) had the lowest adjusted ORs for admission to the hospital, compared with other insured patients. Underinsured patients with DRG of “menstrual and other female reproductive system disorders” (OR, 0.17; 95% CI = 0.06 to 0.51) or “esophagitis, gastroenteritis, and miscellaneous digestive disorders” (OR, 0.55; 95% CI = 0.28 to 0.96) also were less likely to be admitted compared with the other insured group. No significant differences in ICU/operating room admission rates were found between insurance groups. Conclusions: Whereas there was no difference in admission rates to the ICU/operating room by insurance status, this single-center study does suggest an association between insurance status and admission to a general hospital service, which may or may not be causally related. Factors other than provider bias may be responsible for this observed difference.

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