How representative are emergency department data for injuries: Influence of health insurance status

Objectives: To assess the influence health insurance on place of injury treatment and evaluate representativeness of emergency department(ED) data for injuries.

Methods: We analyzed 7,834 medically treated injuries from the 2000-2003 National Health Interview Survey (NHIS). Place of treatment was defined hierarchically as the highest level of ambulatory care provided. We used weighted multiple logistic regression to compare place of treatment for injury episodes covered by private, public and no health insurance.

Results: We estimated 24.5 million injury episodes received medical treatment annually; 55% were treaded in EDs, 11% in clinics/outpatient departments, 28% in doctor's offices, and 3% sought only telephone advice. Privately insured patients used the ED for 50% of injury episodes compared to 64% among those publicly insured and 65% among persons uninsured. After controlling for age, race/ethnicity, geographic region, nature and cause of injury, there was no difference in place of treatment between publicly insured and uninsured persons. However compared to uninsured persons, patients with private insurance were significantly less likely to be treated in the ED for similar injuries (adjusted odds ratio, 0.56; 95% CI 0.47-0.66).

Discussion: Privately insured persons are significantly less likely to use the ED for injury treatment compared to those with public or no insurance, which may affect issues such as quality of and access to care, and costs. Surveillance based on ED databases may not be representative of all medically treated injures which may vary by health insurance status.