International Journal of Preventive Medicine

: 2020  |  Volume : 11  |  Issue : 1  |  Page : 110-

Designing and investigating the validity and reliability of the health literacy questionnaire in Iran: Recognizing the risk factors for cardiovascular diseases, diabetes, and cancer

Fatemeh Rajabi1, Azar Pirdehghan2, Zahra Sanaie3, Laleh Ghadirian4, Azadeh Sayarifard5, Fatemeh Esna-Ashari2,  
1 Community Based Participatory Research Center, Iranian Institute for Reduction of High Risk Behaviors; Center for Academic and Health Policy, Tehran University of Medical Sciences, Tehran, Iran
2 Department of Community Medicine; School of Public Health and Research Center for Health Sciences, Hamadan university of Medical Sciences, Hamadan, Iran
3 Department of Community Medicine, Education Development Office, Hamadan University of Medical Sciences, Hamadan, Iran
4 Knowledge Translation Research Center, Tehran University of Medical Sciences, Tehran, Iran
5 Center for Academic and Health Policy, Tehran University of Medical Sciences, Tehran, Iran

Correspondence Address:
Fatemeh Esna-Ashari
Community Medicine Department, Faculty of Medicine, Hamadan University of Medical Sciences, Shahid Fahmideh St., Hamadan


Background: Health literacy (HL) has been recognized as an important concept in patient education and disease prevention. The rising burden of noncommunicable diseases (NCDs) in Iran is significant. Hence, we designed and validated an HL questionnaire on the most important domains of NCDs, including cardiovascular diseases, diabetes, and cancer. Methods: Literature review was conducted to examine the definition and dimensions of HL. After reaching consensus about the HL dimensions and conceptual models in focus group discussions with experts, they designed questions in each domain. Then, face, content, and construct validity as well as reliability were determined by a pilot study on 72 participants. At the end, a cross-sectional study was implemented on 206 Hamedan university employees, to finalize the questionnaire. Results: After doing the pilot study and analyzing the collected data and according to the Bartlett's test of sphericity and Kaiser–Meyer–Olkin = 0.421 with P < 0.001, factor analysis was used. Considering the eigenvalue >1.4, a 27-item questionnaire in seven domains was obtained which included attitude toward health, understanding information, social support, socioeconomic conditions, access to health services, and application of health information. Cronbach's alpha was more than 0.70 in all domains except the last one (0.47). The second phase showed that overall 75.2% of the individuals had inadequate HL with lowest scores in the application of health information. Conclusions: The designed tool seems appropriate for measuring the HL level among the Iranian population in the field of prevention of cardiovascular disease, cancer, and diabetes. The results can help policy makers to improve health promotion interventions.

How to cite this article:
Rajabi F, Pirdehghan A, Sanaie Z, Ghadirian L, Sayarifard A, Esna-Ashari F. Designing and investigating the validity and reliability of the health literacy questionnaire in Iran: Recognizing the risk factors for cardiovascular diseases, diabetes, and cancer.Int J Prev Med 2020;11:110-110

How to cite this URL:
Rajabi F, Pirdehghan A, Sanaie Z, Ghadirian L, Sayarifard A, Esna-Ashari F. Designing and investigating the validity and reliability of the health literacy questionnaire in Iran: Recognizing the risk factors for cardiovascular diseases, diabetes, and cancer. Int J Prev Med [serial online] 2020 [cited 2020 Aug 4 ];11:110-110
Available from:

Full Text


“Health literacy is linked to literacy and entails people's knowledge, motivation and competences to access, understand, appraise, and apply health information in order to make judgments and take decisions in everyday life concerning healthcare, disease prevention and health promotion to maintain or improve quality of life during the life course.”[1]

The six important dimensions of health literacy (HL) include functional, interactive, autonomous, informational, background, and cultural competencies. HL has affected health behaviors and the use of health services. Furthermore, it affects health outcomes at personal and social levels such as quality of life, health costs, mental health, and equity in health.[1],[2],[3],[4]

Various studies have been conducted in different countries to determine the HL level, but an overall consensus has yet to be reached.[5],[6],[7],[8],[9] The HL level depends on personal traits and the level of communication between people and the health system. Thus, different tools are required for different age groups and different stages of life, and these should be born in mind when measuring HL.[9],[10]

In spite of the various tools and scales present for the assessment of HL, the design and standardization of tools such as the Iranian Urban Population Health Literacy Assessment or the Health Literacy Assessment of Adolescents Tools, and the undertaking of relevant investigations in this field, a scale that is generalizable to the country has not been developed yet.[11],[12] Based on a systematic review in Iran, a localized tool for the assessment of HL is still lacking.[13]

According to existing literature, Iran is exposed to the risk of noncommunicable diseases (NCDs) at an alarming rate,[14],[15],[16],[17] and premature morbidity and mortality resulting from NCDs are on the rise.[18],[19],[20] In Iran, 82.2% of NCD deaths are due to cardiovascular diseases (CVD), cancers, chronic pulmonary diseases, and diabetes; and diabetes mellitus and hypertension have a stronger relationship with sever coronary artery disease.[21],[22]

This study was an effort to design an HL questionnaire on the most important domains of NCD, including CVD, diabetes, and cancer in Iran and to examine its validity and reliability. By doing so, we may achieve basic data on the current status of HL and identify the interventions required for promoting it.


Literature review was conducted to present the definition of HL in a theoretic and functional form that takes into account the various dimensions of the structure under study, one that clearly describes the significance of each of the dimensions. To this end, the ISI, PubMed, Scopus, and Web of Science databases were searched. The search strategy was as follows: 17 keywords (definition, model, concept, dimension, framework, conceptual framework, theory, analysis, qualitative, quantitative, competence, skill, “public health,” communication, information, functional, AND critical) were combined using the preposition “and” with the terms “health literacy,” “health competence,” and health competence (without quotes), and health literacy (without quotes). The inclusion criteria of the studies were as follows: (1) being in English, (2) having examined HL in developing countries, and (3) being relevant to the definition, and/or concept of HL and/or a combination of the two. Using Google's search engine, we further searched the web using the same keywords. We used the references used by the articles and in particular the review studies to complete our documentations. The studies were selected for further reading after examining their titles and abstracts. Thus, the full texts of the selected articles were thoroughly studied. The existing definitions of HL and its conceptual models were extracted from the articles.

Thereafter, two focus group discussions (FGDs) were held with five experts (two community medicine specialists, two internal medicine specialists, and one cardiologist). During these sessions, the conceptual models and definitions obtained from the literature review were discussed and examined for the various dimensions of HL and eventually, consensus was reached. Each of the experts designed appropriate questions for each domain separately. Then, after sharing the questions through email, two more FGDs were held to reach consensus on the initial questions.

The content validity of the questionnaire was examined from the experts' perspective by sending the initial questionnaire to 20 experts. We received 12 completed questionnaires in which the respondents had addressed and scored each of the question's appropriateness, transparency, and comprehensiveness.

Since the target groups of the questions were not experts, two FGDs were held with 15 nonexperts as potential participants of the study and two individuals from the main research team as facilitators. During these meetings, each person separately commented on the appropriateness, transparency, and comprehensiveness of each question and the entire questionnaire in relevant checklists.

Upon summarizing and analyzing the results of the earlier stages (correction or removal of questions that scored lower than 70% in their appropriateness and transparency in the consensus), the initial questionnaire was completed. The pilot study was conducted among 72 employees from Hamedan's Youth and Sports Department; nonrandomized simple sampling was done (23).

The data were analyzed using SPSS. First, the descriptive analysis was done, and then factor analysis was performed to classify the questions.

To finalize the questionnaire, a cross-sectional study was conducted to investigate the HL level of public employees on the risk factors of CVDs, diabetes, and cancer among 206 employees of Hamedan's Bu-Ali Sina University. Random sampling was done.

The data were analyzed using SPSS 16: Statistical Software (Chicago, IL, USA). After descriptive analysis, Cronbach's alpha was calculated for each domain to assess the reliability of each questionnairesection (CVD, diabetes, cancer). To calculate the internal validity of each questionnaire, the overall score for each domain was calculated. Moreover, Pearson's correlation coefficient between the questions of each domain and the overall score of each questionnaire was also computed. A correlation coefficient greater than 0.5 was considered appropriate.

To calculate the score of each domain, the sum of the questions was calculated and divided by the number of questions in that domain. The result was a number between 1 and 5; a score lower than 4 was considered an inadequate level of HL and equal to or greater than 4 was considered as adequate.

Mann–Whitney and chi–square tests were used to examine the association between HL and demographic factors. Level of significance was considered at 5% for all cases.


Based on the agreed definition of HL[1] that covers different dimensions of HL [Table 1], our experts concluded that each individual requires four types of competencies: (1) access: meaning the ability to search, find, and acquire health information; 2) understanding, that is, the ability to understand the available health information; (3) appraisal: meaning the ability to interpret, filter, judge, and assess the health information available; and (4) application: meaning the ability to communicate and utilize information for the sake of adopting decisions that lead to maintenance and improvement of health.{Table 1}

This process creates knowledge and skills that enable the individual to have a higher HL level when s/he is in either of the following three health statuses. Each person is in either of these three health statuses: is unwell or ill in the healthcare system; is at risk of disease in the system of disease prevention; or is a citizen in community health promotion programs, the work environment, educational system, political environment, and the market.

The combination of four dimensions related to health data processing and three levels of individual health status yields 12 dimensions of HL [Table 2]. Understanding HL increases the individuals' competencies over healthcare domains, disease prevention, and health promotion.{Table 2}

Here, upon consultation with the project team and relevant experts, we concluded that at the level of disease prevention, different dimensions of HL (access, understanding, appraisal, and application) should be focused on.

The initial questionnaire on the risk factors of CVD – including 35 questions – was developed. According to the pilot study which was conducted among 72 employees from Hamedan's Youth and Sports Department, seven questions were removed for lack of correlation with the remaining questions. According to the Bartlett's test of sphericity and Kaiser–Meyer–Olkin = 0.421 with P < 0.001, the condition for performing factor analysis was established.

To extract the appropriate components (domain), considering the eigenvalue >1.4, seven components were eventually brought into the component matrix. Overall, 71% variance of the questions under study was describable with the seven selected components.

Correlation values higher than 0.3 were considered for allocating a question to a domain considering the component matrix. Eventually, to specifically load each question in the appropriate domain, the oblimin method was used. The results obtained included a 27-item questionnaire in seven domains, attitude toward health, understanding information, social support, socioeconomic conditions, access to health services, and application of health information.

After doing these steps and conducting the cross-sectional study on 206 employees of Hamedan's Bu-Ali Sina University, these results were obtained. The median overall HL level on recognizing the risk factors of the three diseases was 3.7. The median health literacy levels on recognizing the risk factors for CVD, diabetes, and cancer were 3.53, 3.44, and 3.58, respectively. Except for cancer, the HL level was significantly higher among women for the other two diseases (P = 0.02). A rise in educational status also raised the frequency of adequate HL (P = 0008). Overall, 75.2% of the individuals had inadequate health literacy with regard to the risk factors of all the three diseases. The lowest HL was seen in the application of health information.[23]

To assess the reliability of the questionnaire, Cronbach's alpha was calculated for each domain, the results of which are given below.

In the first domain (the patient's attitude toward health), Cronbach's alpha for the questions on risk factors of cancer, CVD, and diabetes was 0.87, 0.82, and 0.78, respectively. Upon taking into account the questions of all the three diseases, Cronbach's alpha was 0.93.

In the second to sixth domains (understanding information, social support, socioeconomic conditions, access to health services, and communication with a health specialist), considering the similarity of questions in the three questionnaires, Cronbach's alpha was 0.69, 0.71, 0.68, 0.74, and 0.74, respectively.

In the seventh domain (application of health information), Cronbach's alpha for the questions on risk factors of cancer, CVD, and diabetes was 0.43, 0.36, and 0.36, respectively. Upon considering the questions of all the three diseases, Cronbach's alpha was 0.47.

To assess the internal validity of the questionnaire, the overall score of each domain was calculated, and Pearson's correlation among the questions of each domain and their overall scores was obtained; P value was <0.001 for the risk factors of the three diseases in all the domains [Table 3].{Table 3}

To calculate the score based on Likert scale, in each domain, the total score of the questions was computed [Table 4], [Table 5], [Table 6].{Table 4}{Table 5}{Table 6}


In this study, we designed and validated an HL assessment tool for Iran. First, the HL assessment questionnaire was designed based on the items defined in HL – with a focus on prevention of CVD, diabetes, and cancer. After doing a pilot study and analyzing the collected data through factor analysis, seven domains were extracted for the measurement of HL.

After conducting the second stage of data collection aimed at finalizing the questionnaire and performing the analysis, we found that Pearson's correlation coefficient between the questions of each domain and their overall scores was higher than 0.5, which is considered appropriate in internal validity assessment. However, the correlation coefficient was 0.45 for the domain of “application of health information” on cancer risk factors, which contained the following question:

If you are a candidate (age-wise or gender-wise) for performing screening tests for breast, colon, female reproductive organs, and prostate cancers, have you performed at least one test?

Cronbach's alpha for the domain of “application of health information” on cancer risk factors was 0.43, which increased to 0.47 after removing the aforementioned question.

The lack of correlation between the screening question and the other questions could be due to people's inadequate knowledge on cancer screening. The remaining measures related to this domain, such as sports activities and/or healthy nutrition, are being well taught to the public through mass media.

In the same domain, the lowest correlation was observed in the screening questions on CVD and diabetes. Approximately 47% of the individuals reported not performing screening procedures for either CVD or cancer, whereas frequency has been divided among different options in the remaining questions. The public receive no training in the field of screening measures or their timings. Thus, screening procedures had the least correlation with the remaining questions in our questionnaire.

In Japan, a study was conducted to measure functional, communicative, and critical HL among patients with diabetes. The participants of the study were 157 type 2 diabetic outpatients of Tokyo University's Hospital. The inclusion criteria were having type 2 diabetes and being constantly under care of the hospital's endocrinologists. The participants were randomly selected and the objectives and procedure of the research were explained to them. The patients were selected upon examining their electronic records, age, sex, hemoglobin A1C, and other problems. In this study, functional, communicative, and critical HL were assessed. The level of hemoglobin A1C was lower in individuals with higher HL levels. Similar to our study, a close association was observed between HL and reduced complications of chronic diseases.[24]

A semi-structured telephone survey was conducted in a research involving 145 adults in Sweden. A series of questions similar to ours were asked about three risk factors. All the respondents were asked about the measurement of and level of blood pressure, blood glucose, and cholesterol, and whether they had taken any medical measures for either one of them. They were also asked about cigarette smoking and whether they had made any changes in their lifestyles to reduce the risk of CVD.[25]

An Italian study has indicated that the level of awareness of CVD is somewhat vague. Family physicians were generally able to present a quantitative assessment of CVD risk among their patients. CVD prevention programs would be more successful if they emphasized on public knowledge and awareness and family physicians were encouraged to perform more accurate quantitative assessments of CVD risk factors.[26]

In Iran, Tehrani et al. initially underwent the complete stages of validity and reliability testing of the “Test of Functional Health Literacy in Adult” questionnaire. This questionnaire assesses HL at a general level. Thereafter, they used it to examine HL and its determinant factors in five provinces of the country. In the adjusted regression model, they too found that HL was higher among women than in men (P = 0.14). HL level was severely low among individuals of low economic status (P = 0.004).[27]

Khosravi et al. used the “Test of Functional Health Literacy in Adult” questionnaire in another study[28] and assessed the HL level among patients with diabetes in Shiraz. Using the test–retest method, the validity of the questionnaire was calculated at 0.99.

The “Test of Functional Health Literacy in Adult” questionnaire is composed of two sections, numerical understanding and reading. The reading section assesses the patient's ability to read and comprehend texts. These texts are related to the guideline of preparing for upper gastrointestinal imaging, the patient's rights and responsibilities in insurance forms, and the standard hospital consent form. The score considered for this section is between 0 and 50. In the numerical section, the individual's ability to understand and act upon the physician's order – which requires calculation – is evaluated. This section contains 10 health guidelines or descriptions on the utilization of prescribed drugs, the time of visiting the physician, the stages of using financial help, and an example of a medical laboratory test. The score considered for this section is also between 0 and 50. It has 17 questions. The sum of these two sections' scores gives the overall HL score – which is a score between 0 and 100. A score of 0–59 is considered inadequate, 60–74 is considered borderline, and 75–100 is considered as adequate. The mean HL level of patients with diabetes visiting Shiraz's medical centers was calculated at 66, that is, borderline level. HL was significantly associated with age, sex, educational status, membership of the diabetic association, and type of employment.[28]

Tuyen et al. conducted a study in six Asian countries, in which the “Health Literacy Survey Tool European Health Literacy Questionnaire” (HLS-EU-Q47) was validated. This tool contains 47 HL items in the main domain of healthcare, disease prevention, and health promotion. A Likert scale of 1–4 has been used, wherein the responses range from 1 (very difficult) to 4 (very easy). After being translated, the tool was evaluated in a cross-sectional study by being applied on 10,024 participants age 15 years and above. Thereafter, the final analysis was performed using confirmatory factor analysis, internal consistency analysis, and regression analysis. A high internal consistency, with Cronbach's alpha at 0.9, and a satisfactory item-scale convergent validity greater than 0.4 were observed. The HL level in the aforementioned population was strongly correlated with social (P = 0.001) and educational (P < 0.001) status. As an important determinant factor of HL, the latter finding is consistent with our results.[29]

Maindal et al. investigated the HL level in Denmark using a questionnaire that had been designed in Australia for the first time and assessed it for its validity and consistency. This questionnaire contained 44 questions in NINE HL domains (understanding healthcare, having adequate knowledge for health management, active management of health, social support for health, health information assessment, the ability to interact with health caregivers, healthcare navigation system, the ability to find useful health information, and adequate understanding of health information for taking action). The study also assessed the factor structure, homogeneity, reliability, and discriminant validity of the above-mentioned questionnaire. After translation and back-translation, consensus conference, and cognitive interviews with 15 cases, the questionnaire was assessed among 481 individuals. The questions were examined with tests such as level of difficulty, composite scale confidence interval, and confirmatory factor analysis. The factor analysis showed acceptable and high loading (range: 0.49–0.93). Cronbach's alpha and composite reliability were greater than 0.8. Among the responses given, the simplest scale was “social support for health” and the most difficult scale was the “healthcare navigation system.” A Likert scale of 1–4 was used, wherein 1 represented “completely disagree” and 4 represented “completely agree.”[30]

The majority of the above-mentioned studies have measured HL among patients, while our questionnaire measures HL in healthy people in the field of prevention of CVD, cancer, and diabetes to improve health promotion interventions in the population.


Based on the results of this study, the designed tool seems appropriate for measuring the HL level among the Iranian population in the field of prevention of CVD, cancer, and diabetes, and it can be used in different studies.

There is a low level of HL concerning the recognition of risk factors of CVD, diabetes, and cancer. Among the HL domains, the lowest score was obtained in “application of health information” (6%). There is a relatively high frequency of appropriate HL level in the attitude toward, access to, and understanding of information among the patients. Thus, what appears to be generally causing the low level of HL among individuals is the lack of social support and poor economic conditions that have eventually led to the lack of appropriate action toward the application of health knowledge.


We would like to thank all professionals and target groups who gave feedback with regard to the questionnaire in Hamedan University of Medical Science. This research has been completed by helping Vise-Chancellor for Research and Technology of Hamadan University of Medical Science.

Financial support and sponsorship

This study was funded by Vice Chancellor for Research and Technology of Tehran University of Medical Sciences and Health Services grant number 89-04-62-12017.

Conflicts of interest

There are no conflicts of interest.


1Sorensen K, Van den Broucke S, Fullam J, Doyle G, Pelikan J, Slonska Z, et al. Health literacy and public health: A systematic review and integration of definitions and models. BMC Public Health 2012;12:80.
2Berkman ND, Sheridan SL, Donahue KE, Halpern DJ, Crotty K. Low health literacy and health outcomes: An updated systematic review. Ann Intern Med 2011;155:97-107.
3Sayarifard A, Ghadirian L, Mohit A, Eftekhar M, Badpa M, Rajabi F. Assessing mental health literacy: What medical sciences students' know about depression. Med J Islam Repub Iran 2015;29:161.
4Zhang XH, Li SC, Fong KY, Thumboo J. The impact of health literacy on health-related quality of life (HRQoL) and utility assessment among patients with rheumatic diseases. Value Health 2009;12:S106-9.
5Baker DW, Williams MV, Parker RM, Gazmararian JA, Nurss J. Development of a brief test to measure functional health literacy. Patient Educa Couns 1999;38:33-42.
6Baker DW. The meaning and the measure of health literacy. J Gen Intern Med 2006;21: 878-83.
7Begoray DL, Kwan B. A Canadian exploratory study to define a measure of health literacy. Health Promot Int 2012;27:23-32.
8Buchbinder R, Batterham R, Ciciriello S, Newman S, Horgan B, Ueffing E, et al. Health literacy: What is it and why is it important to measure? J Rheumatol 2011;38:1791-7.
9Chisolm DJ, Buchanan BAL. Measuring adolescent functional health literacy: A pilot validation of the test of functional health literacy in adults. J Adolesc Health 2007;41:312-4.
10Fransen MP, Twickler TB, Essink-Bot ML. Health literacy measures: Application and implication. Eur J Public Health 2010;20:269.
11Ghanbari S, Ramezankhani A, Montazeri A, Mehrabi Y. Health literacy measure for adolescents (HELMA): Development and psychometric properties. PloS One 2016;11:e0149202.
12Montazeri A, Tavousi M, Rakhshani F, Azin SA, Jahangiri K, Ebadi M, et al. Health Literacy for Iranian Adults (HELIA): development and psychometric properties. J Iran Inst Health Sci Res (Payesh) 2014;13:589-99 [Persian].
13Tavousi M, Ebadi M, Fattahi E, Jahangiry L, Hashemi A, Hashemiparast M, et al. Health literacy measures: A systematic review of the literature. J Iran Inst Health Sci Res (Payesh) 2015;14:485-96.
14Haagsma JA, Graetz N, Bolliger I, Naghavi M, Higashi H, Mullany EC, et al. The global burden of injury: Incidence, mortality, disability-adjusted life years and time trends from the global burden of disease study 2013. Inj Prev 2016;22:3-18.
15NCD Risk Factor Collaboration (NCD-RisC). Trends in adult body-mass index in 200 countries from 1975 to 2014: A pooled analysis of 1698 population-based measurement studies with 19.2 million participants. Lancet 2016;387:1377-96.
16NCD Risk Factor Collaboration (NCD-RisC). Worldwide trends in diabetes since 1980: A pooled analysis of 751 population-based studies with 4.4 million participants. Lancet 2016;387:1513-30.
17Non-Communicable Diseases (NCD) Country Profiles. Geneva, World Health Organization; 2014. Available from: [Cited 2016 Sep 3].
18Alwan A. The world health assembly responds to the global challenge of noncommunicable diseases. East Mediterr Health J 2013;19:511-2.
19Global Action Plan for the Prevention and Control of Noncommunicable Diseases 2013–2020. Geneva: World Health Organization; 2013. Available from: [Cited 2016 Sep 19].
20Sustainable Development Goals. New York: The United Nations. Available from: [Cited 2016 Oct 2].
21Global Burden of Diseases. Washington, D.C.: Institute of Health Metric and Evaluation; 2014. Available from: [Cited 2016 Sep 3].
22Naghshtabrizi B, Moradi A, Amiri J, Aarabi S, Sanaei Z. An evaluation of the numbers and locations of coronary artery disease with some of the major atherosclerotic risk factors in patients with coronary artery disease. J Clin Diagn Res 2017;11:OC21-4
23Esna Ashari F, Pirdehghan A, Rajabi F, Sayarifard A, Ghadirian L, Rostami M, et al. The study of health literacy of staff about risk factors of chronic diseases in 2014. Sci J Hamadan Univ Med Sci 2015;22:248-54 [Persian].
24Ishikawa H, Takeuchi T, Yano E. Measuring functional, communicative, and critical health literacy among diabetic patients. Diabetes Care 2008;31:874-9.
25Ovhed I, Odeberg H, Troein M, Rastam L. Awareness and treatment of cardiovascular disease risk factors among middle-aged Swedish men and women. Scand J Prim Health Care 1998;16:165-70.
26Celentano A, Panico S, Palmieri V, Guillaro B, Brancati C, Di Palma Esposito N, et al. Citizens and family doctors facing awareness and management of traditional cardiovascular risk factors: Results from the global cardiovascular risk reduction project (Help Your Heart Stay Young Study). Nutr Metab Cardiovasc Dis 2003;13:211-7.
27Tehrani Banihashemi SA, Amirkhani MA, Haghdoost AA, Alavian SM, Asgharifard H, Baradaran H. Health literacy and the influencing factors: A study in five provinces of Iran. J Med Educ Dev Center 2007;4:1-9 [Persian].
28Khosravi A, Ahmadzadeh K, Arastoopoor S, Tahmasbi R. Health literacy levels of diabetic patients referred to Shiraz Health Centers and its effective factors. Health Inf Manage 2015;12:205 [Persian].
29Duong TV, Aringazina A, Baisunova G, Pham TV, Pham KM, Truong TQ, et al. Measuring health literacy in Asia: Validation of the HLS-EU-Q47 survey tool in six Asian countries. J Epidemiol 2017;27:80-6.
30Maindal HT, Kayser L, Norgaard O, Bo A, Elsworth GR, Osborne RH. Cultural adaptation and validation of the Health Literacy Questionnaire (HLQ): Robust nine-dimension Danish language confirmatory factor model. SpringerPlus 2016;5:1232.