Diagnostic ionizing radiation exposure in a population-based sample of children with inflammatory bowel diseases.

OBJECTIVES: The degree of diagnostic radiation exposure in children with inflammatory bowel diseases (IBD) is largely unknown. In this study, we describe this exposure in a population-based sample of children with IBD and determine the characteristics associated with moderate radiation exposure.

METHODS: We ascertained radiological study use, demographic characteristics, IBD medication use, and the requirement for hospitalization, emergency department (ED) encounter, or inpatient gastrointestinal surgery among children with IBD within a large insurance claims database. Characteristics associated with moderate radiation exposure (at least one computed tomography (CT) or three fluoroscopies over 2 years) were determined using logistic regression models.

RESULTS: We identified 965 children with Crohn's disease (CD) and 628 with ulcerative colitis (UC). Over 24 months, 34% of CD subjects and 23% of UC subjects were exposed to moderate diagnostic radiation (odds ratio (OR) 1.71, 95% confidence interval (CI), 1.36 - 2.14). CT accounted for 28% and 25% of all studies in CD and UC subjects, respectively. For CD subjects, moderate radiation exposure was associated with hospitalization (OR 4.89, 95% CI 3.37 - 7.09), surgery (OR 2.93, 95% CI 1.59 - 5.39), ED encounter (OR 2.65, 95% CI 1.93 - 3.64), oral steroids (OR 2.25, 95% CI 1.50 - 3.38), and budesonide (OR 1.80, 95% CI 1.10 - 3.06); an inverse association was seen with immunomodulator use (OR 0.67, 95% CI 0.47 - 0.97). Except for oral steroids and immunomodulators, similar relationships were seen in UC.

CONCLUSIONS: A substantial proportion of children with IBD are exposed to moderate amounts of radiation as a result of diagnostic testing. This high utilization may impart long-term risk, given the chronic nature of the disease.