Impact of guideline recommendation for novel surgical procedures on surgeons’ decisions: a time series analysis of gastric cancer surgeries from a nationwide cohort study

Since two Japanese guidelines, for gastric cancer treatment and for minimally invasive surgery, were simultaneously revised in 2014, laparoscopic distal gastrectomy has been a standard procedure for clinical stage I gastric cancer. MATERIALS AND METHODS: We evaluated the impact of this revision on surgeons’ decision-making using a nationwide inpatient database in Japan. We described the time trends in the proportion of laparoscopic surgery from January 2011 to December 2018. We performed an interrupted time series analysis; the exposure time point was August 2014, and the main outcome was the change in slope before and after the revision of the guidelines. We performed a subgroup analysis of hospital volume and the odds ratio (OR) for postoperative complications according to exposure. RESULTS: A total of 64 910 patients who underwent subtotal gastrectomy for stage I disease were identified. During the study period, the proportion of laparoscopic surgery showed a consistent increase from 47.4 to 81.2%. After the revision, the slope of the increase was rather slow; the OR [95% CI] was 0.601 [0.548–0.654] before the revision and 0.219 [0.176–0.260] after the revision. The adjusted ORs were 0.642 [0.575–0.709] before the revision and 0.240 [0.187–0.294] after the revision. CONCLUSION: The revision of the guidelines recommending laparoscopic surgery had little impact on surgeons’ decisions regarding the choice of procedure.