Health literacy plays an important role in disease prevention and control. As a fundamental component of overall health and well-being, health literacy enables individuals to effectively manage health behaviors, make informed health-related decisions, and achieve positive health outcomes (1). The World Health Organization (WHO) defines health literacy as “the cognitive and social skills which determine the motivation and ability of individuals to gain access to, understand and use information in ways which promote and maintain good health” (2). Studies demonstrated that low health literacy is significantly associated with multiple adverse health outcomes, particularly in chronic disease management and healthcare utilization (3). By contrast, improving health literacy can promote healthy behaviors, enhance disease self-management capabilities, and reduce healthcare burdens (4). Recognizing health literacy's pivotal role, WHO has advocated targeted global action plans to enhance it, with health literacy's promotion now a public health goal in many countries (5, 6).

In 2008, China initiated a systematic survey of health literacy (7, 8). A study indicated that from 2008 to 2022, the proportion of the Chinese population with sufficient health literacy had increased from 6.48% to 27.78%. Specifically, by 2022, more than two-thirds of the population is classified as having insufficient health literacy (9). Zhejiang, located in eastern China and recognized as a paradigm of developed provinces in the country, has a health literacy level that serves as a quintessential case study in the fields of health promotion and public health governance. A study shows that by 2022, the proportion of Zhejiang's population with sufficient health literacy had reached 33.08%, demonstrating the province's exemplary progress in this regard (10). The Healthy Zhejiang 2030 Action Plan clearly designates health literacy as an important indicator and calls for the establishment of a closed-loop system for monitoring and intervention (11). Despite the overall high health literacy, certain subpopulations in Zhejiang—such as older adults, rural residents, and individuals with lower educational level—remain at risk of inadequate health literacy (9). At the same time, the current health literacy policies focus on extensive coverage of the entire population, but fail to take into account the heterogeneity within the population, and lack targeted measures and refined interventions for different groups (12).

As one of China's most economically developed and populous provinces, Zhejiang is experiencing advanced stages of demographic aging and socioeconomic transformation, conditions that are increasingly shared by other regions nationwide. Therefore, examining health literacy patterns in Zhejiang may provide an informative early reference for understanding emerging challenges and guiding future health literacy interventions in other parts of China (9).

Many previous studies have predominantly focused on individuals with specific health conditions (such as cancer or hypertension) or specific age groups (such as adolescents or older adults) (13, 14), which inherently limits the generalizability of research findings (15, 16). Additionally, limited studies have delved into the patterns of health literacy (17). In recent years, the field of health literacy research has increasingly emphasized the importance of adopting comprehensive and multi-dimensional assessment methods (18). Previous studies have indicated that health literacy is complex and heterogeneous, and it is a complex construct jointly influenced by multiple factors (19, 20). However, traditional methodologies often rely on total health literacy scores or average scores measured under different assessment criteria (21, 22). Although this approach facilitates statistical analysis, it may mask important heterogeneities within the population, leading to the neglect of the health literacy characteristics of specific sub-populations (15). In provinces with large and diverse populations such as Zhejiang, where overall health literacy levels are relatively high, the reliance on average-based analyses is particularly likely to obscure vulnerable subgroups. To date, large-scale, population-based studies applying person-centered approaches such as the Latent Profile Analysis (LPA) to examine health literacy heterogeneity in Zhejiang remain scarce, limiting the evidence base for targeted intervention design.

To address this limitation, this study employs the LPA (19, 20). The LPA method is based on individuals' performance characteristics in multiple health literacy dimensions and objectively identifies potential heterogeneous subpopulations by constructing probabilistic models (20, 23). We explore the latent profiles of health literacy among residents aged 15–69 in Zhejiang province, analyse the patterns of health literacy, and examine the characteristic differences and associated factors across distinct latent profiles, with the findings aiming to provide a scientific basis for formulating targeted health intervention strategies (16, 24, 25).

This study applied the LPA to investigate the health literacy patterns among residents aged 15–69 years in Zhejiang Province, China. Three distinct latent profiles were identified: low (15.13%), moderate (32.24%), and relatively high (52.63%) literacy groups. By capturing population heterogeneity, this person-centered approach provides an empirical basis for the development of targeted and differentiated health literacy interventions. Importantly, following the LPA-based classification, educational level, age, and occupation consistently emerged as the most influential factors associated with health literacy, underscoring the necessity of prioritizing these factors in intervention strategies.

The contrasting sociodemographic and health-related characteristics observed between the low and relatively high literacy groups reflect underlying structural inequalities rather than isolated individual factors. Individuals in the low literacy group were more likely to occupy socially disadvantaged positions characterized by older age, rural residence, lower educational level, and poorer health status, which tend to cluster and reinforce one another across the life course (29, 30). From a person-centered perspective, these co-occurring disadvantages converge to form a distinct health literacy profile characterized by limited access to health resources, reduced cognitive and informational capacity, and greater exposure to health risks, including chronic diseases and smoking (4, 18, 31). In contrast, the relatively high literacy group represents an accumulation of social and health advantages, including higher education, urban residency, and better health, which collectively facilitate the acquisition and application of health-related information (32, 33). This pattern highlights the cumulative and interactive nature of social factors in shaping health literacy profiles.

Educational level, age, and occupation emerged as key associated factors of health literacy, a finding that is consistent with existing literature. Educational level was strongly associated with health literacy, with individuals holding a college degree or above demonstrating significantly higher levels of health literacy. Previous studies in Europe and other settings have similarly reported lower health literacy among individuals with lower educational levels (34, 35). Education facilitates health-related decision-making by enhancing information-processing capacity and scientific literacy, such as the ability to understand medical terminology (20, 34, 36).

Age is the second most significant associated factor, with a significantly higher proportion of elderly individuals in the low literacy group. This association may reflect age-related cognitive decline affecting memory and comprehension, as well as the digital divide that limits older adults' access to health information through modern communication technologies (37, 38). Consistent with these findings, international studies have shown a negative correlation between age and health literacy, underscoring age as a key social determinant (34, 39).

Occupation further contributed to disparities in health literacy, with farmers accounting for a substantially higher proportion of individuals in the low literacy group. This pattern likely reflects the combined effects of lower income, high labor intensity, and relatively limited educational opportunities, which together constrain the ability to obtain, understand, and apply health information (40).

The three factors—educational level, age and occupation—jointly constitute the core factors influencing health literacy, with their combined weight reaching as high as 86.5%; this high proportion indicates that any effective intervention strategy can anchor the core resources to these three factors. Factors such as income (6.7%), number of chronic diseases (2.8%), self-rated health (1.7%), marital status (0.8%), and local household registration (0.8%) are moderately associated with residents' health literacy levels, but their influence is relatively limited. The factors with the weakest impact are smoking status (0.4%), place of residence (0.3%), and sex (0.2%).

In terms of research implications, the findings highlight the need for longitudinal tracking systems and cross-regional comparative studies to better understand the dynamic relationships between social factors and health literacy and to assess the generalisability of health literacy profiles across different socioeconomic contexts. In terms of health intervention practices, the results suggest that targeted strategies focusing on key groups defined by educational level, age, and occupation may be more effective than uniform population-wide approaches. At the policy level, establishing coordinated mechanisms across education, elderly care, and employment sectors, while prioritizing health literacy as a policy objective and promoting inter-departmental data sharing, may support sustained improvements in population health literacy.

Several limitations of this study should be acknowledged. First, the cross-sectional design limits the ability to draw causal inferences regarding the relationships between associated factors and health literacy profiles. Second, while this study provides empirical evidence on health literacy profiles and their associated factors, the findings are primarily intended to inform understanding at the analytical level. The translation of these results into specific policy measures or intervention strategies requires further context-specific research to assess feasibility and effectiveness.