The prevalence of low health literacy and its socio-demographic risk factors in Hebei: a provincially cross-sectional survey

Background: This study aimed to evaluate the prevalence of low health literacy in Hebei Province of China, and to investigate its socio-demographic risk factors. Methods: This study was a community-based, cross-sectional questionnaire survey with a multiple-stage randomization design and a sample size of 10560. Participants’ health literacy status was evaluated by a questionnaire based on the 2012 Chinese Resident Health Literacy Scale. Meanwhile, participants’ socio-demographic characteristics were also collected by the questionnaire. Results: A total of 9952 participants provided valid questionnaires and were included in the nal analyses. The mean health literacy score was 63.1±17.1 points; for its subscales, the mean basic knowledge and concepts score, lifestyle score, health-related skills score were 31.7±9.0, 17.2±4.8, 14.3±4.1, respectively. Meanwhile, low health literacy prevalence was 81.0%; for its subscales, low basic knowledge and concepts prevalence (70.6%) was numerically reduced compared to low lifestyle prevalence (87.4%) and low health-related skills prevalence (86.1%). Further analyses showed that age, male and rural area were positively associated, but education level and annual household income were negatively associated with low health literacy prevalence. Further multivariate logistic regression analyses showed that higher age, male, lower education level, lower annual household income and rural area were closely correlated with the risks of low total health literacy or low health literacy in subscales in Hebei Province. Conclusion: The prevalence of low health literacy is 81.0% in Hebei Province. Meanwhile, higher age, male, lower education level, lower annual household income and rural area closely associate with low health literacy risk.

that the prevalence of low health literacy status in Jiangsu Province is 47.5%, and another study reveals that the prevalence of inadequate health literacy status in Beijing is 59%; however, the cut-off of low health literacy differed a lot among different studies [11,12].
The information on local low health literacy prevalence is critical for local government to formulate policy and to allocate resources [5]. As to Hebei Province, a big inland province located in north China with a permanent resident population of 75.92 million, local low health literacy prevalence is not clear.
Therefore, the aim of this study was to investigate low health literacy prevalence in Hebei Province, and to explore its socio-demographic risk factors.

Study population
This study was carried out in Hebei Province of China, where there were 75.92 million permanent residents in 2019. The study was conducted between January 2019 and December 2019, and a total of 10560 residents in Hebei Province participated in this cross-sectional survey. All study populations were permanent residents with age between 16 and 75 years in Hebei Province, where the permanent resident was de ned as the resident who had lived in the Hebei Province for more than 12 months, regardless of whether they had a local household registration or not. While the residents who collectively resided in military bases, hospitals, prisons, nursing homes, or dormitories, were not included in the study. This study was approved by the Research Ethics Committee of Hebei Provincial Centers for Disease Control and Prevention. All participants signed informed consents.

Sample Size Estimation
A multistage, strati ed sampling method was used to select the study population. The core strati cation factors included area (urban and rural), age (16 ~ 35 years, 36 ~ 55 years, 56 ~ 75 years) and gender (male and female). In each strati cation, the sample size was calculated estimated using the formula [13]: , where the parameters were set as follows: prevalence p = 0.89

Sampling Procedures
As shown in Fig. 1, 2 urban areas and 2 rural areas in each province-governed municipality were randomly selected using Probability Proportionate to Size (PPS) sampling . In each chosen urban area, 2  districts were randomly selected with PPS sampling, then 2 communities were randomly selected with   PPS sampling from each chosen district; next, 60 registered households were randomly selected from  each chosen community using random number table, and one resident was selected from each chosen  household with the use of Kish method. In each chosen rural area, 2 towns were randomly selected with   PPS sampling, then 2 villages were randomly selected with PPS sampling from each chosen town; next,  60 registered households were randomly selected from each chosen village using random number table, and one resident was selected from each chosen household with the use of Kish method. As a result, 960 residents in each province-governed municipality were selected, and there were 11 province-governed municipalities in Hebei, resulting in total 10560 residents were sampled. Finally, 608 participants were excluded from analysis because they provided invalid questionnaires due to incorrect lling, then 9952 participants (94.2%) provided valid questionnaires and were included in analysis.

Data Collection
A questionnaire was created for this study, and it consisted of two parts: part 1 was designed to collect participants' socio-demographic characteristics including age, gender, education level, annual household income and location; part 2 was the 2012 Chinese Resident Health Literacy Scale derived from the manual of "Chinese Resident Health Literacy-Basic Knowledge and Skills (trial edition)" published by the Chinese Ministry of Health in 2008 [14]. The questionnaire was completed by the participants themselves. If the participants were unable to ful ll the questionnaire independently due to low literacy level, the faceto-face interview method was adopted, during which the investigators were allowed to make appropriate explanations without the use of inductive or suggestive expression.

Health Literacy Evaluation
The For true-or-false and single-answer questions, 1 point was assigned for a correct answer, and 0 points were assigned for an incorrect answer. For multiple-answer questions, 2 points were assigned if the response contained all correct answers without the wrong ones, and 0 points were given to wrong or omitted answers. The total basic knowledge and concepts score was 47 points, the total lifestyle score was 28 points, and the total health-related skills score was 25 points. The total health literacy score was the sum of the 3 scores, which was ranging from 0 to 100 points. Low health literacy was de ned as the total health literacy score < 80 points (which was 80% of total health literacy score) [8,13]. Low health literacy of basic knowledge and concepts was de ned as the total basic knowledge and concepts score < 38 points (which was 80% of total basic knowledge and concepts score). Low health literacy of lifestyle was de ned as the total lifestyle score < 23 points (which was 80% of total lifestyle score). Low health literacy of health-related skills was de ned as the total health-related skills score < 20 points (which was 80% of health-related skills score).

Statistical analysis
All statistical analyses were carried out using SPSS 24.0 (IBM, Chicago, IL, USA), and gures were plotted using GraphPad Prism 8.01 (GraphPad Software Inc., San Diego, CA, USA). Socio-demographic characteristics and low health literacy prevalence were described as number and percentage. The distribution of total health literacy score was displayed by histogram, and the detailed scores including total health literacy score, basic knowledge and concepts score, lifestyle score, and health-related skills score, were described by mean with standard deviation (SD). Comparison of health literacy scores among subjects with different characteristics was determined by one-way analysis of variance (ANOVA) or Student's t-test. Comparison of low health literacy prevalence among subjects with different characteristics was determined by the Chi-square test. Factors related to low health literacy risk were analyzed by the univariate and forward stepwise multivariate logistic regression model. P value < 0.05 was considered signi cant.

Health Literacy Status
The health literacy score distribution of all participants was shown in Fig. 2A Fig. 2A).

Correlation Analysis Between Participants' Characteristics And Low Health Literacy
As respect to health literacy score, age was negatively correlated, while female, education level, annual household income and resident in urban area were positively correlated with total health literacy score, as well as its subscales including basic knowledge and concepts score, lifestyle score and health-related skills score (all P < 0.001) ( Table 2). Regarding low health literacy prevalence, age was positively associated, but female, education level, annual household income and resident in urban area were negatively associated with low total health literacy prevalence, as well as its subscales low basic knowledge and concepts prevalence, low lifestyle prevalence and low health-related skills prevalence (all P < 0.001) ( Table 3).

Discussion
This study was the rst to explore the low health literacy prevalence and its socio-demographic risk factors in Hebei Province, China to the best of our knowledge. Meanwhile, this study was province-based and had a relatively large sample size, which might assist the local health care workers and government to better understand the health literacy status in Hebei Province. In this study, we found that the mean total health literacy score was 63.1 ± 17.1 points, and the prevalence of low health literacy was 81.0%.
Meanwhile, higher age, male, lower annual household income, lower education level and rural area were closely correlated with low health literacy or its subscales.
Health literacy critically re ects an individual's comprehensive ability in coping with health problems under different circumstances [2]. Previous studies showed that patients with low health literacy have worse outcomes and occupy more public health resource; they might have poor health status and are more likely to be hospitalized [9,10]; meanwhile, they may not fully understand the medical system and treatment strategies, and might be unable to follow the instructions to take medicines appropriately, which often leads to the increased occupation of public health resource [15]. Therefore, understanding the prevalence of local low health literacy could enable local government to make policies and allocate resources [4,5].
Due to the differences in the cut-off of low health literacy, the prevalence of low health literacy varies in different studies [11][12][13]. In order to achieve a comprehensive evaluation, we adopted the standard of low health literacy published by the Chinese Ministry of Health in 2012 [8]. In the present study, we found that the mean total health literacy score was 63.1 ± 17.1 points. Meanwhile. the prevalence of low health literacy was 81.0% in Hebei Province, which was numerically lower than the prevalence of low health literacy in China in 2012 [8]. The difference in the prevalence of low health literacy between Hebei Province and China could be explained by the that: Hubei Province is more developed compared to other inland provinces, meanwhile, several developed areas are located beside Hebei Province, such as Beijing; thus, the average annual household income and education level of residents in Hebei Province might be higher than that of Chinese residents, which resulted in a lower prevalence of low health literacy in Hebei Province. However, our data indicated that low health literacy was still widely prevalent in Hebei Province and speci c strategies should be made to ameliorate its prevalence.
Recognizing risk factors for low health literacy prevalence is critical for the government to modulate policies and strategies to improve local health literacy [16]. According to previous studies, the risk factors for low health literacy include race, resident area (rural or urban), the number of individuals in a household, age, physical exercise, education level, occupation, household income, health information access, etc. [11,17,18]. In the present study, we found that increased age, male, decreased education level, reduced annual household income and resident in rural area were correlated with lower health literacy score, and higher prevalence of inadequate health literacy. Further logistic regression analyses revealed that age, gender, education level, annual household income and resident area were closely correlated with low health literacy. Possible explanations might be that: (1) as the age increased, the eyesight and hearing of an individual might get worse, which might hinder his/her ability in receiving and utilizing information to promote and maintain good health [19]. Meanwhile, in China, people with higher age might have fewer chances to get literate due to historical reasons; (2) according to a previous study, male face with higher occupational stress compared to female [20], which might limit their time on absorbing key information on promoting health status; (3)  promoting and maintaining good health. Therefore, these factors were closely associated with low health literacy risk, which was consistent with the results of several previous studies [11,12,18].
There were several limitations in this study. First of all, this study was based on the questionnaire, which might exist bias in the evaluation of the health literacy status of an individual. Therefore, developing more objective evaluation methods might eliminate this bias. Secondly, in order to achieve higher visualization of the data, some of the continuous variables were converted into categorized variables for statistical analyses, which might cause information loss. Finally, this study was based on a crosssectional survey, thus, the direct casual inferences and the direction of casualty could not be determined.

Conclusion
Collectively, low health literacy is still commonly prevalent in Hebei Province; meanwhile, higher age, male, lower education level, lower annual household income and rural area closely associate with the risk of low health literacy.
Abbreviations PPS: Probability Proportionate to Size; SD: standard deviation Declarations Figure 1 Study sampling process. Study sampling process. Health literacy status in Hebei Province. A: The health literacy score distribution of all participants; B: The mean total health literacy score, basic knowledge and concepts score, lifestyle score, and health-related skills score; C: The prevalence of participants with low health literacy, as well as low health literacy in basic knowledge and concepts, health lifestyle and health-related skills