Longitudinal Trends in Multi-Dimensional Health Literacy Scores: A Nine-Year Joinpoint and Mixed-Model Analysis from Zhejiang, China — A Repeated Cross-Sectional Study

Background Health literacy is a critical determinant of health outcomes and a key indicator for public health promotion. Understanding its long-term trends and domain-specific patterns is essential for targeted health education strategies, yet evidence from comprehensive multi-dimensional assessments remains limited. This study aimed to evaluate the longitudinal trends in health literacy scores—overall, across three dimensions, and across six aspects—among residents of Zhejiang Province, China, from 2016 to 2024. Methods Nine annual repeated cross-sectional surveys were conducted from 2016 to 2024 using a stratified multistage random sampling design across 30 counties in Zhejiang, China. A total of 152,988 valid respondents aged 15–69 years were included. Health literacy was assessed using the nationally standardized Chinese Resident Health Literacy Questionnaire (total score 66). weighted to the census population: the 2010 Zhejiang census data for 2016–2018 surveys and the 2020 Zhejiang census data for 2019–2024 surveys. Joinpoint regression was used to identify inflection points in temporal trends, and linear mixed models were fitted to examine factors associated with health literacy scores, with monitoring site as a random effect. Results All indicators showed significant upward trends over the nine-year period (all P < 0.001). The overall score increased from 39.09 in 2016 to 44.66 in 2024 (annual percent change [APC] = 1.69%, 95% confidence interval [CI]: 1.48–1.92). Among the three dimensions, behaviour and lifestyle showed the largest increase (APC = 2.15%), followed by skills (APC = 1.87%) and knowledge (APC = 1.41%). Among the six aspects, heterogeneous patterns were observed: Chronic Diseases exhibited an inflection point in 2018, and Health Information exhibited an inflection point in 2020, while Infectious Diseases showed a steady linear increase with no joinpoints detected. Urban residents consistently scored higher than rural residents across all indicators, with disparities remaining stable over time. Conclusions Health literacy scores among residents of Zhejiang Province demonstrated sustained and broad-based improvements from 2016 to 2024, though the pace and patterns varied across dimensions and aspects. The findings highlight the need for continued, domain-specific health education efforts, with particular attention to narrowing persistent urban–rural gaps.