Anesthesia practice for Cesarean delivery in Japan: a retrospective cohort study

Purpose: General anesthesia for Cesarean delivery affects maternal and neonatal outcomes. We aimed to evaluate temporal trends in anesthesia management for Cesarean deliveries over 16 years and analyze interinstitutional variations in general anesthesia use in Japan. Methods: In this retrospective cohort study, we obtained patient data from the nationwide health insurance claims database containing data for ten million individuals. We included patients who underwent Cesarean delivery between 1 January 2005 and 31 August 2021. The primary outcome was the use of general anesthesia. We evaluated institutional variations in general anesthesia use in medical facilities using two-level hierarchical logistic regression analyses with median odds ratios and intraclass correlation coefficients. Results: The cohort included 86,793 patients who underwent 102,617 Cesarean deliveries at 2,496 institutions. General anesthesia was used in 3.7% (95% confidence interval [CI], 3.6 to 3.9) of all Cesarean deliveries. The temporal trend in the use of general anesthesia decreased gradually from 10.8% in 2005 to 2.9% in 2021 (P for trend < 0.001). The adjusted median odds ratio for medical facilities was 6.1 (95% CI, 5.9 to 6.7), and the intraclass correlation coefficient was 0.52 (95% CI, 0.51 to 0.55). Conclusion: Although the rate of general anesthesia use for Cesarean delivery in Japan decreased gradually from 2005 to 2021, general anesthesia was used in 3.7% of all Cesarean deliveries. The use of general anesthesia varied significantly across institutions, and 52% of the overall variations in general anesthesia practice can be explained by differences between facilities.