Imaging and insurance: do the uninsured get less imaging in emergency departments?
OBJECTIVE
On average, Americans without health insurance receive fewer health care services than those with insurance. The specific types of services for which the uninsured face access and utilization deficits are not well understood. The authors describe the use of imaging tests in hospital emergency departments (EDs) by nonelderly patients, comparing uninsured, Medicaid, and non-Medicaid insured individuals.


METHODS
The main database used was the 2004 National Hospital Ambulatory Medical Care Survey. The survey contained 2 fields critical to the study: source of payment and imaging services rendered during the ED visit. Source of payment was used to sort ED visit episodes into 3 insurance categories: uninsured, Medicaid, and non-Medicaid insured. Relative value units were assigned to imaging procedures. Imaging procedures were aggregated into 6 modalities. Univariate and multivariate methods were used to compare the number of imaging procedures and associated relative value units across insurance categories. Risk adjustment used the immediacy code, reason for visit, disposition, and demographics.


RESULTS
Compared with comparable insured persons, nonelderly uninsured and Medicaid patients received fewer services in the ED (8% and 10%, respectively, P < .01), even after adjustment for level of acuity. Similar results were found for the value of imaging services received (13% and 19%, respectively, P < .01).


CONCLUSIONS
These results suggest that insurance status influences how much imaging and the intensity of imaging patients receive. Further research is needed to understand whether insured patients receive unnecessary imaging or if uninsured and Medicaid patients receive too little imaging.
Econometrica, Bethesda, Maryland, USA.
James W
JW
Moser
Kimberly E
KE
Applegate
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003952:Diagnostic Imaging / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016018:Least-Squares Analysis; D008297:Male; D008484:Medicaid; D017057:Medically Uninsured; D008875:Middle Aged; D012044:Regression Analysis; D015895:Relative Value Scales; D020379:Risk Adjustment; D014481:United States; D014600:Utilization Review