Determinants of Health Literacy and Its Associations With Health-Related Behaviors, Depression Among the Older People With and Without Suspected COVID-19 Symptoms: A Multi-Institutional Study

Purpose: We examined factors associated with health literacy among elders with and without suspected COVID-19 symptoms (S-COVID-19-S). Methods: A cross-sectional study was conducted at outpatient departments of nine hospitals and health centers 14 February−2 March 2020. Self-administered questionnaires were used to assess patient characteristics, health literacy, clinical information, health-related behaviors, and depression. A sample of 928 participants aged 60–85 years were analyzed. Results: The proportion of people with S-COVID-19-S and depression were 48.3 and 13.4%, respectively. The determinants of health literacy in groups with and without S-COVID-19-S were age, gender, education, ability to pay for medication, and social status. In people with S-COVID-19-S, one-score increment of health literacy was associated with 8% higher healthy eating likelihood (odds ratio, OR, 1.08; 95% confidence interval, 95%CI, 1.04, 1.13; p < 0.001), 4% higher physical activity likelihood (OR, 1.04; 95%CI, 1.01, 1.08, p = 0.023), and 9% lower depression likelihood (OR, 0.90; 95%CI, 0.87, 0.94; p < 0.001). These associations were not found in people without S-COVID-19-S. Conclusions: The older people with higher health literacy were less likely to have depression and had healthier behaviors in the group with S-COVD-19-S. Potential health literacy interventions are suggested to promote healthy behaviors and improve mental health outcomes to lessen the pandemic's damage in this age group.


INTRODUCTION
The COVID-19 pandemic has upended public health systems around the globe (1,2), and spurring millions of health, research and administrative professionals to seek ways to mitigate transmission and mortality (3,4). Older people are at high risk of more severe health conditions from COVID-19 disease (5,6). By the time the virus killed 350,000 people, the over-60 death rate was estimated at 75%. The pandemic also has caused panic and mental illness, especially for the elderly (7,8). Quarantine and lockdown contain infection but they negatively impact mental health (9)(10)(11). Different approaches are needed to mitigate the pandemic's psychological effects (12,13).
Health literacy (HL) is known as a crucial means to appraise health-related information for preventing non-communicable and infectious diseases. It helps people achieve better quality care and improves disease management, lifestyle, and health outcomes (14,15). Health literacy is considered a crucial element in public health strategies to protect people from disease (16,17). This has never been more important than during the COVID-19 epidemic (18,19). Vietnam has a high risk of coronavirus infection, having a long border with China, and Vietnamese people have lower health literacy scores when ranked among other Asian countries (20). Finding factors associated with health literacy can assist in planning interventions to reduce health inequalities during the epidemic.
This study explores determinants of health literacy and its associations with health-related behaviors and depression among older people with and without suspected COVID-19 symptoms (S-COVID-19-S).

Study Design
We conducted a cross-sectional study on outpatient department (OPD) visitors 14 February−2 March 2020. The study was reviewed and approved by the nine participating hospitals and health centers as well as the Institutional Ethical Review Committee of Hanoi School of Public Health in Vietnam (IRB No. 029/2020/YTCC-HD3).

Study Participants and Settings
Patients recruited in the study were ages 60-85 years, able to communicate in Vietnamese, and visited an OPD during the study period. Participants were excluded if they were in any emergency condition or if they were diagnosed with psychotic disorders, dementia or blindness. The process of recruiting participants is detailed in a previous study (15). We

Data Collection Procedure
The interviewers (e.g., nurses, staff, and medical students) at each hospital or health center had received 4 h of training for the data collection; the sessions were led by two senior researchers with a detailed protocol. Technical guidance for prevention and control of COVID-19 disease was also provided during the training, including mask use, hand washing and physical distancing (4).
Interviewers invited OPD visitors to participate in the survey after signing consent form. The interviews were conducted at the OPDs using printed questionnaires that took about 20 min to complete. Personal information (e.g., name, identification) was anonymized before the analysis.

Demographic Characteristics and Clinical Indicators
Socio-demographic indicators assessed included age (date of birth), gender (female, male), marital status (never, ever married), education (illiterate or elementary school, junior high school, high school, college/university, or above), occupation (employed, business owner, others), social status (low, middle, or high level), and ability to pay for medication (very difficult to very easy).

Health-Related Behaviors
Health-related behaviors included current smoking status (no vs. yes), drinking status (no vs. yes), and eating behaviors during the COVID-19 outbreak (unchanged or less healthy, or healthier). The seven-item International Physical Activity Questionnaire short version (IPAQ-SF) asked patients' activities (vigorous, moderate, walking, and sitting) over the past 7 days before the OPD visiting date (22,23). The overall physical activity score as MET-min/week was calculated for each subject and used in the analysis (24).

Health Literacy
We used a short-form questionnaire (HLS-SF12) to measure health literacy (15,25,26). People were asked about the perceived difficulty of 12 items on a 4-point Likert scale (1 = very difficult to 4 = very easy). We calculated the general health literacy (HL) index score using the formula (1): where the HL index is ranged from 0 to 50; M is the mean of 12 items of HLS-SF12. The higher HL index indicates a greater HL level (25,27).

Depression
We assessed depression using patient health questionnaire with 9 items (PHQ-9) that had been validated and used in Vietnam (28)(29)(30). Patients rated each item using the 4-point Likert scale from 0 = not at all to 3 = almost every day for the past 14 days. The depression scores range from 0 to 27, with those scoring ≥10 classified as having depression (31).

Statistical Analysis
The distributions of studied variables were explored using descriptive analysis. The Student's t-test and Chi-square tests were used appropriately for continuous and categorical variables. The determinants of health literacy were examined using simple and multiple linear regression analysis. Next, the simple and multiple binary logistic regression analyses were used to examine the associations of health literacy (as a predictor/independent variable) with binary outcome variables such as BMI (normal weight vs. overweight/obese), smoking status (non-smoking vs. smoking), drinking (non-drinking vs. drinking), eating behavior (eat less healthily or unchanged vs. eating healthier diet), depression (not depressed vs. depressed). The simple and multiple multinomial logistic regression analyses were used to examine the association between health literacy and physical activity (tertile-1 vs. tertile-2, tertile-3). Variables showing significant associations with outcome variables in simple regression models were selected for multiple regression models. In order to avoid multicollinearity, the Spearman's correlation coefficient test was used to check associations between independent variables. If independent variables correlated with one another at rho ≥ 0.3, one representative independent variable was selected to the multiple regression model. The significance level was set at a p-value < 0.05. Data were analyzed using SPSS for windows, version 20.0 (IBM Corp, Armonk, NY, USA).

Demographic Characteristics of Participants
Out of sample, percentages of older people with S-COVID-19-S, and depression were 48.3% (448/928), and 13.4% (124/928), respectively. The mean age and health literacy scores were 68.2 ± 6.51, and 25.7 ± 8.09, respectively. The proportion of people with S-COVID-19-S varied with different categories of educational attainment, occupation, comorbidity, ability to pay for medication, social status, BMI, drinking, physical activity, and depression. People with S-COVID-19-S also had lower HL score than those without ( Table 1).     Table 3), full model is presented in Supplementary Table 9.

education (for with S-COVID-19-S group only), occupation (for with S-COVID-19-S group only), and social status (for both groups) (Supplementary
For smoking status, the model was adjusted for gender (for both groups) (Supplementary Table 4), full model is presented in Supplementary Table 10. Table 5), full model is presented in Supplementary Table 11. Table 6), full model is presented in Supplementary Table 12. Table 7), full model is presented in Supplementary Table 13.  Table 3).

DISCUSSION
Our study shows men had higher health literacy scores compared to women for both with and without S-COVID-19-S groups. Previous studies showed men facing higher risks of worse health outcomes and death from COVID-19 disease, especially among older adults (32)(33)(34)(35). Similarly, older people (ages 71-85 years) had lower health literacy compared to the younger group (ages 60-70 years) in both with and without S-COVID-19-S groups. The findings were consistent with other studies finding health literacy levels lower among elders in various nations and periods (36,37). Likewise, higher levels of education and social status were associated with higher health literacy scores in older people, which is in line with previous studies (38,39). Therefore, improving health literacy might be a strategic approach to prevent COVID-19 and minimize its consequences, especially in men and the older people. In addition, active engagement of the elderly is encouraged to contain the pandemic (40,41). Governments must provide detailed, timely and accurate information regarding the epidemic, particularly about prevention efforts and self-protective behaviors that minimize new infections (42)(43)(44). Vietnam's Ministry of Health has led all health institutions and related sectors to collaborate with the public against the COVID-19 epidemic (45). The government has encouraged people to enhance behaviors such as washing hands, wearing masks, and following updated healthrelated information to prevent the disease and improve health literacy (46). The COVID-19 pandemic has devastated economies and labor markets, especially reducing jobs and workers' earnings (47). Vietnam's GDP is $2,740, lower than many industrializing nations, so its people particularly fear the pandemics' impacts on household income, such as not able to cover daily living costs or health care expenses (48). Our study shows elders with better ability to pay medication had higher health literacy scores in both with and without S-COVID-19-S groups. This evidence calls for a quick response from governments in terms of stimulus packages to cover food, water, essential goods, basic health services, and medical costs during the crisis (46).
In the current study, we found health literacy significantly associated with healthier diet and physical activity only in older people with S-COVID-19-S. This can be explained by those participants facing higher projected risks of coronavirus infection and severe outcomes. They arguably have the most to gain from practicing healthy lifestyles (e.g., healthy dietary intake and more physical activity) to protect and improve their health-related quality of life (46,49).
One important finding was that higher health literacy scores were associated with lower likelihood of depression in older people with S-COVID-19-S. This finding is similar to previous studies (50,51). In our previous study, higher health literacy scores also were associated with lower fear of COVID-19 and lower likelihood of depression (15). We observed that nearly 13% of elders had depressive symptoms with 22.5 and 4.8% of participants with and without S-COVID-19-S, respectively. This might indicate that the uncertain progression of the COVID-19 epidemic affects mental health possibly leading to hypochondriasis, worry about being infected, and fear of the uncontrollable epidemic's consequences (52).
The study has several limitations. First, causality cannot be generated on the basis of a cross-sectional design. The findings could be considered for further studies regarding the pandemic, especially in elderly participants. Second, the study was conducted during the sensitive time period of the global COVID-19 pandemic, when all participants and interviewers might have been at risk of infection. Researchers and leaders of hospitals and health centers made great efforts to protect the safety of study participants, and fortunately there were no new cases during the data collection period. In addition, have selected 9 hospitals and health centers in three parts of Vietnam, yet the sample may not fully-represent the general Vietnamese population. Finally, while we cannot follow-up with the participants to assess long-term associations, future longitudinal studies with larger samples are suggested to confirm these findings.

CONCLUSIONS
In groups with and without S-COVID-19-S, the factors of age, gender, education, ability to pay for medication, and social status were significantly associated with health literacy. Elders with higher health literacy had greater likelihood of healthier behavior (e.g., healthy eating, physical exercise) and lower likelihood of depression, especially in the S-COVID-19-S group. Because improved health literacy protects elders, our findings should be helpful for policy-makers worldwide.

DATA AVAILABILITY STATEMENT
The raw data supporting the conclusions of this article will be made available on reasonable request to the corresponding author.

ETHICS STATEMENT
The study was reviewed and approved the Institutional Ethical Review Committee of Hanoi University of Public Health, Vietnam (IRB No. 029/2020/YTCC-HD3).