Age-period-cohort and bayesian age-period-cohort prediction modeling of hepatitis C incidence and mortality in China.

BACKGROUND

Hepatitis C remains a significant public health challenge in China, despite global advancements in treatment and prevention. This study aimed to investigate the age, period, and cohort effects on hepatitis C incidence and mortality trends in China and project future trajectories to inform targeted interventions.

METHODS

Data on hepatitis C incidence, mortality, and age-standardized rates (ASIR/ASMR) from 1992 to 2021 were extracted from the Global Burden of Disease (GBD) 2021 database. Joinpoint regression analyzed annual percentage change with 95% confidence intervals (CI). Age-period-cohort (APC) model evaluated relative risks (RR) of age, period, and birth cohort effects using Poisson regression. A Bayesian APC (BAPC) model projected trends from 2022 to 2035.

RESULTS

From 1992 to 2021, hepatitis C incidence cases declined by 31.54% (1,655,914 to 1,133,610 cases), ASIR declined by 39.00% (152.23 to 92.85 per 100,000, estimated annual percentage change [EAPC] = -1.99%, 95% confidence interval [CI]: -2.32%--1.67%). Mortality counts rose by 28.60% (36,869 to 51,638 deaths), yet ASMR decreased (EAPC=-1.76%, 95%CI: -1.89%--1.63%). Gender disparities persisted: females had higher ASIR (157.73 vs. males: 147.86 per 100,000 in 1992 and 93.23 vs. males: 93.10 per 100,000 in 2021) but lower ASMR (3.96 vs. males: 4.67 per 100,000 in 1992 and 2.28 vs. males: 2.89 per 100,000 in 2021). The APC model analysis revealed elevated risks for pre-1962 birth cohorts (incidence relative risk [RR] = 1.479, 95%CI: 0.391-5.601; mortality RR = 2.496, 95%CI: 2.094-2.975) and declining period effects post-2004 (incidence RR = 0.757, 95%CI: 0.635-0.902; mortality RR = 0.618, 95%CI: 0.553-0.690). The BAPC model projections indicated continued ASIR declines by 2035, yet female incidence is expected to rise (87.45 to 95.21 per 100,000), contrasting with male declines (83.94 to 74.71 per 100,000). Mortality rate will decrease, but absolute deaths remain substantial.

CONCLUSIONS

Declining standardized rates reflect progress in prevention and treatment scale-up, yet rising mortality cases underscore the enduring burden of undiagnosed infections. Targeted interventions for aging cohorts, gender-specific strategies, and equitable access to direct-acting antivirals are critical to achieving hepatitis C elimination. Policymakers must prioritize enhanced screening, public awareness, and resource allocation to mitigate disparities and align with WHO 2030 goals.