Background: Computed tomography (CT) was commonly used in children with mild head injuries. People in Japan are concerned about radiation exposure and radiation-induced cancer because of the Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011. This study investigated whether the accident influenced the use of CT in children with mild head injuries.
Methods: Using the Japan Medical Data Center database, we identified patients aged ≤ 15 years visiting hospitals because of mild head injuries from January 1, 2008, to December 31, 2013. We excluded patients who were admitted to the hospital or received other medical examinations. Regression discontinuity analysis was used to compare proportions of patients undergoing head CT and having clinically important traumatic brain injury (ciTBI) overlooked before vs. after the accident, adjusting for patient characteristics, secular trends, and hospital effect.
Results: Eligible patients (n = 40,440) were classified as visiting the hospital before (n = 11,659) or after (n = 28,781) the accident. The regression discontinuity analysis showed that the accident was associated with a reduction in the proportion of patients undergoing head CT (odds ratio [OR]: 0·73; 95% confidence interval [CI]: 0·63–0·86), whereas the accident was not associated with an increase in cases where ciTBI was overlooked (OR: 0·72; 95% CI: 0·13–4·00).
Conclusions: The use of CT in children with mild head injuries declined after the Fukushima Daiichi Nuclear Power Plant accident. Improving awareness of radiation exposure risks among patients and physicians could reduce unnecessary CT.