Variation in the utilization of angioembolization for splenic injury in hospitals: a nationwide cross-sectional study in Japan.

Aim: Substantial variations in the utilization of angioembolization have been reported internationally. However, the existence of variations in the utilization of angioembolization in Japan is currently unknown. Methods: This was a cross-sectional study using data from a nationwide trauma registry in Japan. Of the 4,896 registered adult patients with splenic injury, we investigated 3,319 patients in the top 25% of the hospitals that registered the highest number of splenic injury patients in the Japan Trauma Data Bank. The primary outcome of this study was initial angioembolization. We calculated the expected initial angioembolization rates using multiple regression analysis adjusted for patient factors. In addition, we evaluated the range of observed-to-expected initial splenic angioembolization ratio for each hospital. Moreover, we assessed whether this ratio was increased with time. Results: The frequency of initial splenic angioembolization ranged from 0% to 52%. The median expected initial angioembolization rate, calculated through multiple logistic regression analysis, was 19.7%. The observed-to-expected initial splenic angioembolization ratio for each hospital ranged from 0 to 2.36. The observed initial angioembolization rate tended to increase with time ( Conclusions: Despite adjustment for patient factors, substantial variations were observed in the utilization of splenic angioembolization among hospitals in Japan.