JMIR Publications

ABSTRACT

Background:

The COVID-19 pandemic, with its unprecedented global scale and intensive public health interventions, functioned as a unique, large-scale "natural experiment" in population health education. It remains unclear whether this event led to sustained, broad improvements in public literacy regarding infectious diseases beyond COVID-19 itself.

Objective:

This study aimed to evaluate the longitudinal trends in infectious disease-specific health literacy (IDSHL) among residents of Zhejiang Province, China, from 2019 (pre-pandemic) to 2024 (post-pandemic), to assess the lasting impact of this "natural experiment."

Methods:

Six annual cross-sectional surveys were conducted from 2019 to 2024 across 30 counties in Zhejiang Province, using consistent multistage stratified random sampling and a validated 12-item IDSHL questionnaire assessing knowledge, behavior, and skills. Annual sample sizes ranged from 17,131 to 19,257 (total N=112,917). Joinpoint regression and multivariate logistic regression were used to analyze trends and identify associations.

Results:

Population-weighted overall IDSHL scores increased significantly from 2019 (mean=10.46, SD=3.09) to 2024 (mean=11.40, SD=2.88) (P<.001). All subscale scores (knowledge, behavior, skills) showed significant upward trends (all P<.001). Joinpoint regression revealed the most rapid annual increase in the proportion of residents with adequate IDSHL occurred during the acute pandemic phase (2019-2021: APC=9.42%, P<.001), which slowed significantly post-2021 (2021-2024: APC=2.28%, P=.074). Correct response rates surged for items directly related to pandemic messaging (e.g., respiratory etiquette increased from 28.44% to 39.67%), but knowledge on non-respiratory diseases like hepatitis B fluctuated without a clear sustained gain. Adjusted analysis, using 2021 as the reference year, confirmed the lowest odds of adequate IDSHL in 2019 (OR=0.741) and the highest in 2024 (OR=1.098).

Conclusions:

The COVID-19 pandemic served as a potent natural experiment, catalyzing a significant and sustained improvement in population-level IDSHL, particularly in pandemic-relevant knowledge and behaviors. However, the effect was time-sensitive, with accelerated gains during the acute crisis decelerating afterward, and was not uniform across all disease domains or demographic groups. Post-pandemic health strategies must reinforce comprehensive IDSHL through sustained education and address the digital information landscape to bridge persistent equity gaps.