Cross-country inequalities in global burden of gastrointestinal cancers: a slope and concentration index methods

Abstract Purpose To explore cross-country inequalities in global disease burdens of colon and rectum cancer (CRC), esophageal cancer (EC) and gastric cancer (GC). Methods Data from the Global Burden of Diseases Study 2019 were analyzed to examine trends in disability-adjusted life-years (DALYs) for three cancers using Estimated Annual Percentage Change (EAPC) and Joinpoint analysis. Inequality in DALYs rates was assessed with the Slope Index of Inequality and the Concentration Index, based on the Socio-Demographic Index (SDI). Results From 1990 to 2019, age standardized DALYs rate of CRC decreased in high and high-middle SDI regions, with the EAPC values of -1.018 and − 0.161, but increased among low, low-middle and middle SDI regions (EAPC = 1.035, 0.926 and 0.406, respectively). The DALYs rates of EC and GC decreased in all SDI regions. For CRC, the slope index changed from 358.42 (95% confidence interval: 343.28 to 370.49) to 245.13 (217.47 to 271.24); from − 63.88 (-87.48 to -48.28) to -1.36 (-32.44 to 25.87) for EC; from 126.37 (101.97 to 146.47) to 58.04 (20.54 to 96.12) for GC. The concentration index for CRC moved from 29.56 (28.99 to 29.84) to 23.90 (23.19 to 24.26); from − 9.47 (-10.30 to -9.24) to -14.64 (-15.35 to -14.24) for EC; from 8.44 (7.85 to 8.72) to -6.42 (-7.65 to -6.12) for GC. Conclusion This study suggests strong heterogeneity in global DALYs for gastrointestinal cancers across different SDI regions. Higher SDI regions faced a greater burden of CRC, while the burdens of EC and GC were more prevalent in lower SDI regions.