Impact of socioeconomic status on ionizing radiation exposure from medical imaging in children

Purpose: To characterize cumulative radiation exposure from diagnostic imaging (CEDI) in pediatric patients and to investigate its relationship to patients' socioeconomic status and comorbid medical conditions. Methods: A retrospective cohort study of >19,000 pediatric patients seen within the outpatient clinic system of an academic tertiary care urban medical center during the month of January 2006 was conducted to estimate CEDI from all procedures performed within 3 years of the index visit (until January 2009). Socioeconomic status was estimated from census tract geocoding. Comorbid medical conditions were identified from the electronic medical record. Results: A total of 19,063 patients underwent imaging tests within the index month. The mean age was 8.9 ± 6.3 years. Most had private insurance (56%), with 36% receiving Medicaid and 8% private payers. Our population lived in census tracts in which 27 ± 16% of the population were below the federal poverty level with 62% living in areas in which 20% of residents were living below the poverty level. There were differences in CEDI (P <.0001) by age, insurance type, and percentage poverty in the census tract of residence but not among racial groups (P =.6508). The association between poverty and CEDI was generally explained by the 26 Elixhauser diagnoses, with the exception of rheumatoid arthritis. Conclusion: Patients living in areas of greater poverty were exposed over time to more radiation from diagnostic testing than those living in areas with lower percentages of residents living in poverty. This association was explained almost entirely by the presence of disease burden. No direct association was found between socioeconomic status and CEDI.