Global bladder cancer quality of care index improves from 1990 to 2021 but its future trend plateaus around 2040

This study evaluates spatiotemporal trends of the bladder cancer Quality of Care Index (QCI), identifies its key predictive factor, and projects future trends at global, regional, and national levels. Based on Global Burden of Disease (GBD) data from 1990 to 2021, we constructed a QCI (scaled 0–100) using principal component analysis. Holt-Winters triple exponential smoothing was employed to forecast future trends, with a prediction interval (PI) quantified. A Random Forest model was developed to quantify the nonlinear associations of age, gender, and year on QCI, and its performance was rigorously validated using temporally-blocked cross-validation. SHapley Additive exPlanations (SHAP) was applied to interpret the model. The global QCI for bladder cancer increased by 21.0% (95% confidence interval, CI: 19.4–22.6%) between 1990 and 2021, showing a positive correlation with the sociodemographic index ( r = 0.90, 95%CI: 0.89–0.94, P < 0.001). A five-fold gap existed in 2021 between high-income North America (QCI 99.22, 95%CI: 98.71–99.61) and Central Sub-Saharan Africa (QCI 18.51, 95%CI: 16.20–20.94). Age emerged as the strongest predictive factor, with the QCI showing an inverted U-shape trend peaking at ages 35–39, Projections indicate the global QCI will plateau around 2040 (QCI 81.58, 95% PI: 73.71–88.38). Although bladder cancer care has significantly improved, future advancements are expected to stagnate. This necessitates a strategic shift toward achieving equitable and sustainable care, particularly for elderly populations and underserved regions.