Inverse Association Between Regional Availability of Board‐Certified Fellows of the Japan Gastroenterological Endoscopy Society and Colorectal Cancer Mortality in Japan: An Ecological Analysis

ABSTRACT Aims We investigated the association between prefecture‐level colorectal cancer (CRC) mortality and contributing factors, including the regional availability of Board‐Certified Fellows of the Japan Gastroenterological Endoscopy Society (BCFJGES), using publicly available data from all 47 Japanese prefectures. Methods and Results This prefecture‐level ecological cross‐sectional study used publicly available national data from e‐Stat, Cancer Statistics by the Japan National Cancer Center, and JGES records. The dependent variable was the CRC‐specific age‐standardized mortality rate (AMR) among individuals aged < 75 years in 2021. Independent variables (2010–2016) included CRC screening and follow‐up rates, smoking, alcohol consumption, obesity, physical activity, diabetes prevalence, red meat consumption, mean income, gastroenterologist and BCFJGES density per 10 000 population, CRC stage distribution, and regional classification. Simple linear regression showed that smoking, alcohol consumption, and obesity were significantly associated with higher CRC AMR, whereas physical activity, income, and BCFJGES density were associated with lower AMR. Multiple linear regression confirmed independent associations for smoking (regression coefficient [ b ] = 0.213, p = 0.011), alcohol consumption ( b = 0.045, p = 0.003), physical activity ( b = −0.087, p = 0.024), and BCFJGES density ( b = −1.339, p < 0.001). The Pearson correlation coefficient between AMR and BCFJGES density was −0.482 ( p < 0.001). Conclusion Higher prefecture‐level smoking and alcohol consumption were associated with higher CRC mortality, while higher physical activity and higher BCFJGES density were associated with lower mortality. Regional disparities in BCFJGES distribution across Japan may contribute to CRC mortality and warrant continued surveillance and policy attention.