Long-term effects of human development on the global burden of gallbladder and biliary tract cancer: a longitudinal multilevel analysis, 1990-2021.

AIM: To evaluate the longitudinal effect of human development on the global burden of gallbladder and biliary tract cancers (GBTC) from 1990 to 2021.

BACKGROUND

GBTCs are rare but highly fatal malignancies with substantial geographic heterogeneities in incidence and mortality. Socioeconomic development, quantified through Human Development Index (HDI), may influence GBTC burden, but its long-term impact has not been quantified using longitudinal data.

METHODS

This ecological study analyzed Global Burden of Disease (GBD) 2021 estimates across 204 countries. Four age-standardized indicators were examined, incidence rate (ASIR), mortality rate (ASMR), years-of-life-lost rate (ASYLLR), and mortality-to-incidence ratio (MIR). Temporal trends and HDI effects were evaluated using a longitudinal multilevel Gamma generalized linear mixed model (GLMM) to account for regional clustering and global heterogeneity.

RESULTS

Between 1990 and 2021, all four indicators declined in both development groups, with steeper reductions in more-developed countries. The ASMR and ASYLLR were initially higher in high-HDI regions but declined more rapidly, crossing below less-developed regions in the early 2000s. MIR showed a delayed but sharper decrease, falling below 1 in more-developed settings around 2010, while remaining above 1 in less-developed areas. The longitudinal GLMM confirmed significant HDI-time interactions (p < 0.001), indicating faster burden reduction with higher development levels.

CONCLUSION

Human development is strongly associated with accelerated declines in GBTC incidence, mortality, and fatal burden. The results highlight the critical role of socioeconomic progress, healthcare infrastructure, and early detection in reducing disparities, underscoring the importance of targeted investments in low- and middle-HDI countries to achieve more equitable global cancer control.