The impact of socioeconomic status and comorbid medical conditions on ionizing radiation exposure from diagnostic medical imaging in adults

Purpose: The aim of this study was to characterize cumulative exposure to ionizing radiation from diagnostic imaging (CEDI) in adult patients and investigate its relationship to a patient's socioeconomic status and comorbid medical conditions. Methods: A retrospective cohort study was conducted of 54,015 patients seen within the outpatient clinic system of an academic, tertiary care, urban medical center during the month of January 2006, estimating the 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 9,537 adult patients were seen within the index month and underwent imaging tests. Eighty percent were living in areas with >10% poverty. Thirty-six percent of men and 43% of women had diagnoses from the Elixhauser list. Mean CEDI values were 10 ± 19.09 mSv for those from areas with >10% poverty and 8.9 ± 22.42 mSv for those living in areas with <10% poverty. Poverty and comorbidities covaried. Estimated CEDI within groups of patients with the same comorbidity was not associated with socioeconomic status. Conclusion: At this institution, there is a high prevalence of patients living in poverty. Those living in poverty are at higher risk for comorbid conditions that are associated with increased CEDI. However, controlling for comorbidity, socioeconomic status was no longer predictive of CEDI.