Evaluation of Insurance Type as a Proxy for Socioeconomic Status in the Pediatric Emergency Department: A Pilot Study.

Study Objective: To determine whether insurance status can function as a sufficient proxy for socioeconomic status in emergency medicine research by examining the concordance between insurance status and direct socioeconomic status measures in a sample of pediatric patients.

Methods: We conducted a cross-sectional pilot study of patients aged 5 to 17 years in the emergency department of a quaternary care children's hospital. Socioeconomic status was measured using the highest level of the caregiver's education (low: less than bachelor's degree; high: bachelor's or greater) and previous year household income (low: <$75,000; high: ≥$75,000). We calculated the misclassification rate of insurance status (low: public; high: private) using education and income as reference standards. Results were expressed as percentages with 95% confidence intervals.

Results: In total, 300 patients were enrolled (median age 11 years, 44% female). Insurance status misclassified 23% (95% CI 18% to 28%) and 14% (95% CI 10% to 19%) of patients when using caregiver education and income, respectively, as reference standards.

Conclusions: Insurance status misclassified socioeconomic status in up to 23% of pediatric patients, as measured by caregivers' education and income. Emergency medicine studies of pediatric patients using insurance as a covariate to adjust for socioeconomic status may need to consider this misclassification and the resulting potential for bias. These findings require confirmation in larger, more diverse samples, including adult patients.