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Prevalence of and factors associated with health literacy among people with Noncommunicable diseases (NCDs) in South Asian countries: A systematic review

Open AccessPublished:November 03, 2022DOI:https://doi.org/10.1016/j.cegh.2022.101174

      Abstract

      Problem considered

      Health literacy increases the ability of people living with non-communicable diseases (PLWNCDs) to read and understand medical information, access health information and health services, and involvement in shared decision-making required for improving health outcomes and health behaviours. This systematic review aimed to synthesize available evidence on the prevalence and associated factors of adequate and inadequate health literacy among PLWNCDs in South Asian countries.

      Methods

      Based on PRISMA guidelines, a systematic review of primary studies published between 2010 and 2021 was carried out using four electronic databases and search engines, namely Medline (PubMed and EBSCOhost), CINAHL, Scopus, and Google search engines with various key search terms. Data were extracted, and the findings were narratively synthesized.

      Results

      A total of thirteen studies were included from four countries, and most of them were from Pakistan. The review found that majority of PLWNCDs had inadequate health literacy. The prevalence of inadequate health literacy was higher among people with diabetes (26.00%–80.88%), cardiovascular disease (51.80%–83.43%), and chronic obstructive pulmonary disease (74.80%–79.00%). No studies were found assessing the level of health literacy among people with chronic kidney diseases. Various factors such as poor disease knowledge, no or less educational attainment, belonging to an indigenous or marginalised community from rural areas, and being female were found to be associated with inadequate health literacy.

      Conclusion

      Overall, our review found that PLWNCDs had inadequate health literacy. Therefore, it is important to design and implement interventions focusing on improving health literacy among PLWNCDs, which can help promote healthy behaviours and improve the skills to self-manage NCDs in South Asian countries.

      Keywords

      1. Introduction

      Noncommunicable diseases (NCDs) are one of the most emerging public health burdens that have posed significant global challenges to the healthcare system.
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      A study by Martinez et al. (2020) reports that 83.9% (approximately 34.5 million) of global NCD deaths could be averted through the provision of high-quality health care, addressing common risk factors such as tobacco use, harmful use of alcohol, unhealthy diet and low level of physical activity,
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      Previous studies from high-income settings documented the effectiveness of HL-sensitive self-management interventions on positive health outcomes. People with an adequate level of health literacy were found to have better healthy lifestyle practices, positive change in SNAPW (smoking, nutrition, alcohol, physical activity, and weight), good self-rated health, self-efficacy, better disease knowledge, self-management of disease, and better health outcomes.
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      South Asia, home to one-quarter of the world's population and more than one-third (approximately 37.00%) of the world's poor people, has been noted to have a surging prevalence of NCDs.

      The World Bank. World bank countries and lending groups. Available from::https://datahelpdesk.worldbank.org/knowledgebase/articles/906519.

      The increasing burden of NCDs in the South Asian region requires increased health care services and crucial participation of people, mainly those with NCDs, in the management of the disease. The Shanghai Declaration from the WHO in 2016 endorsed the importance of HL and identified it as a key for health promotion to achieve Sustainable Development Goals (SDGs) agenda.
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      Policy Brief 4 : Health Literacy. 9th Global Conference On Health Promotion.
      This highlights the importance and need to understand the factors associated with inadequate HL, which helps design people-centred HL interventions among people with low levels of HL. Low or inadequate HL is a significant problem among PLWNCDs in LMICs, and primary studies on HL focusing PLWNCDs in South Asian Countries are evolving. To date, there is no comprehensive review that documented HL prevalence and its associated factors among PLWNCDs in South Asia. Therefore, this systematic review was conducted to summarise the prevalence of HL and its associated factors among PLWNCDs.

      2. Materials and methods

      This systematic review is reported in accordance with the Preferred Reporting Items for Systematic Review (PRISMA) guidelines.
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      The PRISMA 2020 statement: an updated guideline for reporting systematic reviews.
      The protocol was registered in the international prospective register of systematic reviews, PROSPERO (CRD 42021230029).

      2.1 Literature search strategy

      A comprehensive search was done in electronic databases, namely Medline (accessed through EBSCOhost and PubMed), CINAHL, and Scopus. Additionally, Google Scholar was searched to identify potential studies. The journal articles published in English between January 1, 2010 to December 31, 2021 were searched by combining key search terms (both Medical Subject Headings (MeSH) and free-text keywords) using Boolean operators (“AND” & “OR”). The search terms used in this review are presented in BOX 1.
      Search terms
      (“Health Literacy” OR “Adequate Health Literacy” OR “Inadequate Health Literacy”) AND (“Non-communicable disease” OR “NCD” OR “Diabetes” OR “Type 2 diabetes” OR “Diabetes Mellitus” OR “Chronic Kidney Disease” OR “CKD” OR “Cardiovascular disease” OR “CVD” OR “Heart Disease” OR “Hypertension” OR “High Blood Pressure” OR “Stroke” OR “Coronary Heart Disease” OR “Chronic obstructive pulmonary disease” OR “COPD”) AND (“South Asia” OR “Nepal” OR “India” OR “Pakistan” OR “Bangladesh” OR “Sri Lanka” OR “Afghanistan” OR “Bhutan” OR “Maldives”).

      2.2 Inclusion and exclusion criteria

      This systematic review included the studies using quantitative methods (cross-sectional studies, case-control studies, and cohort studies), which have studied HL or domains of HL using a validated tool and the factors associated with HL among PLWNCDs. PLWNCDs in this review were those who were diagnosed or living with cardiovascular diseases, chronic kidney diseases, diabetes, and chronic obstructive pulmonary disease, irrespective of other chronic co-morbidities. This review included studies conducted in South Asian settings. There was no restriction imposed on the age and gender of the participants.
      We excluded systematic reviews, randomised control trials, conference papers, opinions, letters to the editors, newspaper articles, theses, and studies with only abstracts. The review also excluded the studies that measure knowledge, awareness, and studies exclusively conducted on cancer, chronic autoimmune disease, and mental illness.

      2.3 Study selection process

      The search yield was imported to Mendeley, and duplicates were removed. Subsequently, the reviewers (BK and BRB) independently screened the title and abstracts for relevance, and the eligible articles were selected for full-text screening. Thereafter, the full-text articles were retrieved and screened against the preselected inclusion and exclusion criteria. Any discrepancy between reviewers during the screening process regarding inclusion and exclusion was resolved by discussion until consensus was achieved. If consensus was not reached, another reviewer's (UNY) opinion was sought to decide on inclusion.

      2.4 Quality assessment and data extraction

      The quality assessment of the included studies was performed independently by two reviewers (BK and BRB) using a critical appraisal checklist developed by Joanna Briggs Institute (JBI).
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      Each item of the critical appraisal checklist was assigned one point with a total maximum score of eight. The total score of each study was calculated as a percentage, and the quality was assigned as good with a score of 80.00%–100%, fair with a score of 50.00%–80.00%, and poor with a score <50.00%.
      • Goldsmith M.R.
      • Bankhead C.R.
      • Austoker J.
      Synthesising quantitative and qualitative research in evidence-based patient information.
      Data were extracted from all the included studies into an excel spreadsheet. The information extracted from the included studies were study identifiers (authors name and article published year), country, details on NCDs, populations, settings (a place where the study was conducted), literacy tool, study design, factors, and result.

      2.5 Data synthesis

      Due to heterogeneity in the tools for measuring HL in the included studies, we could not perform a meta-analysis. Instead, we have conducted a narrative synthesis. Firstly, the studies were grouped in accordance with the four NCDs that addressed the prevalence of HL. The associated factors of HL were also categorized on the basis of inadequate and adequate HL among PLWNCDs.

      3. Results

      The database search yielded 1618 relevant records, of which 1361 unique records were screened after duplicates were removed. The titles and abstracts were screened for relevance, and 1255 articles were removed. In the next step, a total of 18 full-text studies that fit the inclusion criteria were assessed, of which five ineligible articles were excluded, and their reasons for exclusion were documented. Following the PRISMA guidelines, the included articles are presented in Fig. 1.

      3.1 Study characteristics and critical appraisal of included studies

      A total of thirteen cross-sectional studies met the inclusion criteria. Of them, six were from Pakistan, four were from India, two were from Nepal, and one study was from Bangladesh. Most of the studies (n = 11) were carried out in healthcare settings
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      ,
      • Singh S.
      • Acharya S.D.
      • Kamath A.
      • Ullal S.D.
      • Urval R.P.
      Health literacy status and understanding of the prescription instructions in diabetic patients.
      ,
      • Saleem F.
      A cross sectional assessment of health literacy among cardiovascular patients in Karachi, Pakistan.
      • Mehzabin R.
      • Hossain K.J.
      • Moniruzzaman M.
      • Sayeed S.J.
      Association of functional health literacy with glycemic control: a cross sectional study in urban population of Bangladesh.
      • Saqlain M.
      • Riaz A.
      • Malik M.N.
      • et al.
      Medication adherence and its association with health literacy and performance in activities of daily livings among elderly hypertensive patients in Islamabad, Pakistan.
      • Saeed H.
      • Saleem Z.
      • Naeem R.
      • Shahzadi I.
      • Islam M.
      Impact of health literacy on diabetes outcomes: a cross-sectional study from Lahore, Pakistan.
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      • Hussain N.
      • Said A.S.
      • Khan Z.
      Influence of health literacy on medication adherence among elderly females with type 2 diabetes in Pakistan.
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      • Ramasamy D.
      • Singh A.K.
      • Mohan S.K.
      Association of sociodemographics, technology use and health literacy among type 2 diabetic individuals living in an Indian setting: an exploratory cross-sectional study.
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      , and two
      • Yadav U.N.
      • Lloyd J.
      • Hosseinzadeh H.
      • Baral K.P.
      • Bhatta N.
      • Harris M.F.
      Levels and determinants of health literacy and patient activation among multi-morbid COPD people in rural Nepal: findings from a cross-sectional study.
      ,
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      were carried out in the community settings. The sampling method was outlined in nine studies, of which five studies used the convenience sampling method,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      ,
      • Saqlain M.
      • Riaz A.
      • Malik M.N.
      • et al.
      Medication adherence and its association with health literacy and performance in activities of daily livings among elderly hypertensive patients in Islamabad, Pakistan.
      ,
      • Hussain N.
      • Said A.S.
      • Khan Z.
      Influence of health literacy on medication adherence among elderly females with type 2 diabetes in Pakistan.
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      • Ramasamy D.
      • Singh A.K.
      • Mohan S.K.
      Association of sociodemographics, technology use and health literacy among type 2 diabetic individuals living in an Indian setting: an exploratory cross-sectional study.
      one used the simple random sampling method,
      • Yadav U.N.
      • Lloyd J.
      • Hosseinzadeh H.
      • Baral K.P.
      • Bhatta N.
      • Harris M.F.
      Levels and determinants of health literacy and patient activation among multi-morbid COPD people in rural Nepal: findings from a cross-sectional study.
      one used the time-based sampling method,
      • Saleem F.
      A cross sectional assessment of health literacy among cardiovascular patients in Karachi, Pakistan.
      one used the purposive sampling method,
      • Mehzabin R.
      • Hossain K.J.
      • Moniruzzaman M.
      • Sayeed S.J.
      Association of functional health literacy with glycemic control: a cross sectional study in urban population of Bangladesh.
      and one used random sampling method.
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      Six studies used face-to-face interviews, one used the telephone call method, while others administered questionnaires to patients for data collection. The studies included a broad range of sample size, ranging from 50 to 524 participants. The details of the study characteristics are presented in Table 1. The critical appraisal of included studies are presented as supplementary file.1.
      Table 1Characteristics of included studies.
      Study, YearCountryStudied NCDStudy populationSettingsLiteracy toolStudy designResult
      Shrestha et al., 2018 (37)NepalHypertension, Diabetes and COPDDiabetic (n = 161), hypertension (164) and COPD patients (n = 101)B.P. Koirala Institute of Health Science, Dharan and community hospital, Sunsaripretested short version of HLS-EU-ASIA-Qcross-sectional study; face to face interviewInadequate health literacy
      Singh et al., 2018 (38)IndiaDiabetes18 years above, diabetic patients (n = 263)Outpatient departments of tertiary care hospitalsREALMcross-sectional study; face to face interviewInadequate health literacy
      Yadav et al., 2020 (39)NepalCOPD18–70 years multi-morbid COPD population (n = 238)Rural Municipality of Sunsarifive HLQ domains out of nine HLQ domainscross-sectional study; interview administeredInadequate health literacy
      Saleem et al., 2015 (40)PakistanCVDPatients with cardiovascular complication (n = 163)Tertiary care institute, karachiPre-validated questionnaire on HLdescriptive cross-sectional surveyInadequate health literacy
      Mehzabin et al., 2019 (41)BangladeshDiabetes18 years and above diabetic population (n = 200)Bangladesh University of Health and Science Hospital, Dhakas-TOFHLA and DKQ-10 scalecross-sectional; semi-structured questionnaireInadequate health literacy
      Saqlain et al., 2019 (42)PakistanHypertension≥65 years, diagnosed with hypertension and at least taking one medication for the previous one month (n = 262)Pakistan Institute of Medical Sciences, Islamabadsingle item literacy screener (SILS) developed by Morris et al.descriptive cross-sectional survey; interview administeredInadequate health literacy
      Saeed et al., 2018 (43)PakistanDiabetes>30 years diabetic patients (n = 204)Service hospital, Mayo hospital, Sheikh Zayed hospital and Nobel hospital, Lahores-TOFHLAcross-sectional studyInadequate health literacy
      Shahzad et al., 2018 (44)PakistanHypertension≥18 years hypertensive patients using antihypertensive medications for last 6 months (n = 285)Sandeman Provincial Hospital, QuettaNine HLQ domainsQuestionnaire based cross-sectional surveyDomains 1,2,7–9: inadequate health literacy.

      Domains 3–6: adequate health literacy
      Hussain, Said & Khan, 2020 (45)PakistanDiabetes>60 years female with diabetes and concurrent cardiovascular disease (n = 524)Private hospitals, LahoreLiteracy assessment for Diabetes (LAD) and Diabetes Numeracy Test (DNT)Cross-sectional survey; face to face interviewAdequate health literacy
      Sahoo, Kohli & Kishore, 2015 (46)IndiaDiabetes and Hypertension≥18 years patients with diabetes (n = 50), hypertension (n = 50) and anemia (n = 50)Tertiary care teaching hospital, DelhiPilot tested questionnaire for health literacyCross-sectional study; interview administeredDiabetes-adequate health literacy

      CVD- adequate health literacy
      Ramasamy et al., 2016 (47)IndiaDiabetes≥18 years patients with diabetes (n = 100)Saveetha Medical College, ChennaiModified version (STOFHLA)Exploratory cross-sectional studyInadequate health literacy
      Suhail et al., 2021 (48)PakistanIschemic heart disease>25 years patients with disease duration more than six months (n = 251)Mayo Hospital, LahoreValidated questionnaire developed by chew et al.Descriptive cross-sectional; face to face interviewsInadequate health literacy
      Gautam et al., 2021 (49)IndiaDiabetes, Hypertension or both≥18 years patients with diabetes (n = 136), with hypertension (n = 181), diabetes and hypertension (n = 95)Urban area of Jodhpur, RajasthanHLS-EU-Q47Cross-sectional; telephonically contactedInadequate health literacy

      3.2 Health literacy measurement tools

      There was heterogeneity in measurement tools that assessed HL in the included studies (Table 2).
      Table 2Methodological quality of included studies.
      Study referenceInclusion criteriaSubjects and settingReliable/valid exposure measureMeasurement of condition standardIdentification of confounding factorsConfounding factors statedValid/reliable outcome measureAppropriate statistical analysisScores (%)
      Shrestha et al., 2018++N/AN/A+++5/6 (83%)
      Singh et al., 2018++N/AN/A++4/6 (67%)
      Yadav et al., 2020++N/AN/A++++6/6 (100%)
      Saleem et al., 2015++N/AN/A++4/6 (67%)
      Mehzabin et al., 2018++N/AN/A++4/6 (67%)
      Saqlain et al., 2019++N/AN/A+++5/6 (83%)
      Saeed et al., 2018++N/AN/A++4/6 (67%)
      Shahzad et al., 2018++N/AN/A_+++5/6 (83%)
      Hussain, Said & Khan, 2020++N/AN/A++4/6 (67%)
      Sahoo, Kohli & Kishore, 2015++N/AN/A++4/6 (67%)
      Ramasamy et al., 2016++N/AN/A+++5/6 (83%)
      Suhail et al., 2021++N/AN/A+++5/6 (83%)
      Gautam et al., 2021++N/AN/A+++5/6 (83%)
      +satisfies criteria, - does not satisfies criteria.

      3.3 Prevalence of health literacy

      The included studies in this review presented either the prevalence of adequate or inadequate HL or both. One study measured the prevalence of HL based on cut-off value, where a mean score less than the cut-off value on each domain of HL was considered as limited or low HL, while a mean score greater than the cut-off value on HL domains was considered as adequate HL.
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      This review did not find any national-level HL studies conducted on PLWNCDs in South Asian countries. The prevalence of HL for individual NCDs has been detailed in Table 3.
      Table 3Health literacy measurement tools and prevalence of health literacy.
      CountryStudy IDOutcome assessment tool/scaleNo. of peopleInadequate HLProblematic/marginal HLAdequate HL
      • 1
        People living with diabetes
      NepalShreshta et al., 2018 (37)Short version of the Europe-Asia-Health Literacy Survey Questionnaire (HLS-EU-ASIA-Q), score 0-1616141.00% [inadequate (0–8)]19.90% [problematic (9–12)]39.10% [sufficient (13–16)]
      IndiaSahoo, Kohli & Kishore, 2015 (46)Health literacy questionnaire5026.00% (not understanding information about blood sugar level)Not Mentioned74.00% (understanding information about blood sugar level), 84.00% understanding regimen of medications
      IndiaSingh et al., 2018 (38)Rapid Estimate of Adult Literacy in Medicine (REALM), score 0-6626363.00% [low (0-44)]28.00% [marginal (45–60)]9.00% [higher (61–66)]
      PakistanSaeed et al., 2018 (43)Short Test of Functional Health Literacy (s-TOFHLA), score 0-3620467.20% [inadequate (0-16)]17.60% [marginal (17–22)]15.20% [adequate (23–36)]
      PakistanHussain, Said & Khan, 2020 (45)Literacy assessment for Diabetes (LAD) and Diabetes Numeracy Test (DNT)52440.00% [inadequate (score<85%)]Not Mentioned57.20% [adequate (score>86%)]
      BangladeshMehzabin et al., 2019 (41)Short form Test of the Functional Health Literacy in Adults (s-TOFHLA), score 0-3620060.50% [inadequate (0-16)]15.50% [marginal (17–22)]24.00% [adequate (23–36)]
      IndiaRamasamy et al., 2016 (47)Modified version of short test of functional health literacy in adults (STOFHLA)

      Score always-never
      100Item 1 (60.00%), Item 2 (56.00%), Item 3 (57.00%), Item 4 (54.00%), Item 5 (54.00%) [sometimes-always]Item 1 (40.00%), Item 2 (44.00%), Item 3 (43.00%), Item 4 (46.00%), Item 5 (46.00%) [occasionally-never]
      IndiaGautam et al., 2021 (49)European Health Literacy Survey Questionnaire (HLS-EU-Q47), Score 0-5013680.88% [limited (0-33)]19.11% [adequate (34–50)]
      • 2
        People living with cardiovascular diseases
      NepalShreshta et al., 2018 (37)Short version of the Europe-Asia-Health Literacy Survey Questionnaire (HLS-EU-ASIA-Q), score 0-1616451.80% [inadequate (0–8)]22.00% [problematic (9-12)]26.20% [sufficient (13–16)]
      IndiaSahoo, Kohli & Kishore, 2015 (46)Pilot tested questionnaire for health literacy50Not MentionedNot Mentioned76.00% understanding information about blood pressure, 60.00% understanding medication regimen
      PakistanSaleem et al., 2015 (40)Pre-validated questionnaire on HL16357.00% [inadequate]Not MentionedNot Mentioned
      PakistanSaqlain et al., 2019 (42)Single item literacy screener (SILS) developed by Morris et al., score 1-526262.60% [inadequate]Not Mentioned37.40% [adequate]
      PakistanShahzad et al., 2018 (44)Nine Health Literacy Questionnaire (HLQ) domains285Domain 1 (12 ± 2.60, 12.50), Domain 2 (11.63 ± 2.62, 12.50), Domain 7 (21.86 ± 4.13, 22.50), Domain 8 (17.67 ± 4.18, 18.50), Domain 9 (18.17 ± 3.98, 18.50)Not MentionedDomain 3 (14.97 ± 3.18, 14.50), Domain 4 (15.70 ± 2.95, 14.50),Domain 5 (14.55 ± 3.42, 14.50), Domain 6 (18.70 ± 3.82, 18.50)
      IndiaGautam et al., 2021 (49)European Health Literacy Survey Questionnaire (HLS-EU-Q47), Score 0-5018183.43% [limited (0-33)]16.57% [adequate (34–50)]
      PakistanSuhail et al., 2021 (48)Sixteen Item Questionnaire developed by Chew et al. score 0–6425170.11% [inadequate (0-34)]29.88% [adequate (35–64)]
      • 3
        People living with chronic obstructive pulmonary disease
      NepalShreshta et al., 2018 (37)Short version of the Europe-Asia-Health Literacy Survey Questionnaire (HLS-EU-ASIA-Q), score 0-1610177.20% [inadequate (0–8)]12.90% [problematic (9-12)]9.90% [sufficient (13–16)]
      • 4
        People living with co-morbidities
      NepalYadav et al., 2020 (39)five HLQ domains out of nine Health Literacy Questionnaire (HLQ) domains, score lower quartile-upper quartile238Low [HPS (79.00%), HIS (76.50%), SS (77.30%), AE (75.20%), and UHI (74.80%)]Not MentionedHigh [HPS (21.00%), HIS (23.50%), SS (22.70%), AE (24.80%), and UHI (25.20%)]
      IndiaGautam et al., 2021 (49)European Health Literacy Survey Questionnaire (HLS-EU-Q47), Score 0-509581.05% [limited (0-33)]18.95% [adequate (34–50)]
      AE: Ability to find the good health information; HIS: Having sufficient information to manage my own health; HPS: Feeling understood and supported by healthcare providers; SS: Social support for health; UHI: understand the health information well enough to know what to do.

      3.4 Prevalence of HL in people with diabetes

      The prevalence of HL among people living with diabetes was measured by eight studies in four countries: Nepal,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      Pakistan,
      • Saeed H.
      • Saleem Z.
      • Naeem R.
      • Shahzadi I.
      • Islam M.
      Impact of health literacy on diabetes outcomes: a cross-sectional study from Lahore, Pakistan.
      ,
      • Hussain N.
      • Said A.S.
      • Khan Z.
      Influence of health literacy on medication adherence among elderly females with type 2 diabetes in Pakistan.
      Bangladesh,
      • Mehzabin R.
      • Hossain K.J.
      • Moniruzzaman M.
      • Sayeed S.J.
      Association of functional health literacy with glycemic control: a cross sectional study in urban population of Bangladesh.
      , and India.
      • Singh S.
      • Acharya S.D.
      • Kamath A.
      • Ullal S.D.
      • Urval R.P.
      Health literacy status and understanding of the prescription instructions in diabetic patients.
      ,
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      ,
      • Ramasamy D.
      • Singh A.K.
      • Mohan S.K.
      Association of sociodemographics, technology use and health literacy among type 2 diabetic individuals living in an Indian setting: an exploratory cross-sectional study.
      ,
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      The prevalence of inadequate HL among people with diabetes was higher in community settings
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      than that in hospital settings.
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      ,
      • Singh S.
      • Acharya S.D.
      • Kamath A.
      • Ullal S.D.
      • Urval R.P.
      Health literacy status and understanding of the prescription instructions in diabetic patients.
      ,
      • Mehzabin R.
      • Hossain K.J.
      • Moniruzzaman M.
      • Sayeed S.J.
      Association of functional health literacy with glycemic control: a cross sectional study in urban population of Bangladesh.
      ,
      • Saeed H.
      • Saleem Z.
      • Naeem R.
      • Shahzadi I.
      • Islam M.
      Impact of health literacy on diabetes outcomes: a cross-sectional study from Lahore, Pakistan.
      ,
      • Hussain N.
      • Said A.S.
      • Khan Z.
      Influence of health literacy on medication adherence among elderly females with type 2 diabetes in Pakistan.
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      • Ramasamy D.
      • Singh A.K.
      • Mohan S.K.
      Association of sociodemographics, technology use and health literacy among type 2 diabetic individuals living in an Indian setting: an exploratory cross-sectional study.
      Prevalence of inadequate HL was 41.00% and 60.50% in Nepal
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      and Bangladesh
      • Mehzabin R.
      • Hossain K.J.
      • Moniruzzaman M.
      • Sayeed S.J.
      Association of functional health literacy with glycemic control: a cross sectional study in urban population of Bangladesh.
      respectively. Variation in the prevalence of inadequate HL was observed in various geographical locations in India, with 26.00% in Delhi,
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      80.88% in Rajasthan,
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      54.00%–60.00% in Chennai
      • Ramasamy D.
      • Singh A.K.
      • Mohan S.K.
      Association of sociodemographics, technology use and health literacy among type 2 diabetic individuals living in an Indian setting: an exploratory cross-sectional study.
      , and 63.00% among various hospitals.
      • Singh S.
      • Acharya S.D.
      • Kamath A.
      • Ullal S.D.
      • Urval R.P.
      Health literacy status and understanding of the prescription instructions in diabetic patients.
      Dissimilarity in the prevalence of inadequate HL was also observed in studies from Pakistan. A study published in 2018 found 67.20% prevalence of inadequate HL
      • Saeed H.
      • Saleem Z.
      • Naeem R.
      • Shahzadi I.
      • Islam M.
      Impact of health literacy on diabetes outcomes: a cross-sectional study from Lahore, Pakistan.
      , and a study among elderly females with diabetes in 2019 found 40.00% with inadequate HL
      • Hussain N.
      • Said A.S.
      • Khan Z.
      Influence of health literacy on medication adherence among elderly females with type 2 diabetes in Pakistan.
      (Table 3).

      3.5 Prevalence of HL among people with cardiovascular diseases

      Seven studies measured the prevalence of HL among people with CVDs.
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      ,
      • Saleem F.
      A cross sectional assessment of health literacy among cardiovascular patients in Karachi, Pakistan.
      ,
      • Saqlain M.
      • Riaz A.
      • Malik M.N.
      • et al.
      Medication adherence and its association with health literacy and performance in activities of daily livings among elderly hypertensive patients in Islamabad, Pakistan.
      ,
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      ,
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      ,
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      ,
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      Of these studies, four were from Pakistan,
      • Saleem F.
      A cross sectional assessment of health literacy among cardiovascular patients in Karachi, Pakistan.
      ,
      • Saqlain M.
      • Riaz A.
      • Malik M.N.
      • et al.
      Medication adherence and its association with health literacy and performance in activities of daily livings among elderly hypertensive patients in Islamabad, Pakistan.
      ,
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      ,
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      one from Nepal,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      and two from India.
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      ,
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      Most of the studies
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      ,
      • Saleem F.
      A cross sectional assessment of health literacy among cardiovascular patients in Karachi, Pakistan.
      ,
      • Saqlain M.
      • Riaz A.
      • Malik M.N.
      • et al.
      Medication adherence and its association with health literacy and performance in activities of daily livings among elderly hypertensive patients in Islamabad, Pakistan.
      ,
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      ,
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      ,
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      included in this review have measured HL in health care settings and one has measured in community settings.
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      Five studies measured HL among patients with hypertension,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      ,
      • Saqlain M.
      • Riaz A.
      • Malik M.N.
      • et al.
      Medication adherence and its association with health literacy and performance in activities of daily livings among elderly hypertensive patients in Islamabad, Pakistan.
      ,
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      ,
      • Sahoo M.
      • Kohli C.
      • Kishore J.
      Health literacy levels among outpatients at a tertiary hospital in Delhi, India.
      ,
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      ; one study measured HL among people with ischemic heart disease
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      , and one study measured HL among people with CVD complications.
      • Saleem F.
      A cross sectional assessment of health literacy among cardiovascular patients in Karachi, Pakistan.
      Studies conducted in various cities in Pakistan found 57.00%, 62.60%, and 70.11% people with inadequate HL in Karachi,
      • Saleem F.
      A cross sectional assessment of health literacy among cardiovascular patients in Karachi, Pakistan.
      Islamabad
      • Saqlain M.
      • Riaz A.
      • Malik M.N.
      • et al.
      Medication adherence and its association with health literacy and performance in activities of daily livings among elderly hypertensive patients in Islamabad, Pakistan.
      , and Lahore
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      , respectively. Also, inadequate HL was found among CVDs patients from Quetta, Pakistan, on various domains of HL.
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      The results from Nepal
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      and India
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      showed 51.80% and 83.43% prevalence of inadequate HL, respectively.

      3.6 Prevalence of HL among people with COPD

      Of all South Asian countries, HL focusing COPD was measured in studies conducted in Nepal.
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      ,
      • Yadav U.N.
      • Lloyd J.
      • Hosseinzadeh H.
      • Baral K.P.
      • Bhatta N.
      • Harris M.F.
      Levels and determinants of health literacy and patient activation among multi-morbid COPD people in rural Nepal: findings from a cross-sectional study.
      One of the studies was carried out in healthcare settings,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      while another was conducted in community-based settings.
      • Yadav U.N.
      • Lloyd J.
      • Hosseinzadeh H.
      • Baral K.P.
      • Bhatta N.
      • Harris M.F.
      Levels and determinants of health literacy and patient activation among multi-morbid COPD people in rural Nepal: findings from a cross-sectional study.
      The study conducted in health care settings found 77.20% prevalence,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      while the study conducted among rural communities found more than three-quarters of the participants with inadequate HL on various domains of HL
      • Yadav U.N.
      • Lloyd J.
      • Hosseinzadeh H.
      • Baral K.P.
      • Bhatta N.
      • Harris M.F.
      Levels and determinants of health literacy and patient activation among multi-morbid COPD people in rural Nepal: findings from a cross-sectional study.
      (Table 3).
      One of the studies measured HL among people with both Diabetes and Hypertension and found 81.05% prevalence of inadequate HL.
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.

      3.7 Factors associated with HL

      This review identified various factors associated with adequate and limited HL among PLWNCDs. The associates of HL varied according to the characteristics of participants and the nature of NCD conditions.
      A study from Nepal found poor knowledge of COPD and its risk factors,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      being uneducated on HL domains, feeling understood and supported by healthcare providers (HPS), having sufficient information to manage own health (HIS), ability to find good health information (AE), understand the health information well enough to know what to do (UHI), being female on HIS, AE and UHI, low family income (≤ USD 176 per month) on domain AE, and being low ethnic group (Indigenous or Dalit) on domain social support for health (SS)
      • Yadav U.N.
      • Lloyd J.
      • Hosseinzadeh H.
      • Baral K.P.
      • Bhatta N.
      • Harris M.F.
      Levels and determinants of health literacy and patient activation among multi-morbid COPD people in rural Nepal: findings from a cross-sectional study.
      associated with inadequate HL.
      The factors associated with adequate HL among people with diabetes were higher knowledge of diabetes,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      higher educational attainment,
      • Singh S.
      • Acharya S.D.
      • Kamath A.
      • Ullal S.D.
      • Urval R.P.
      Health literacy status and understanding of the prescription instructions in diabetic patients.
      ,
      • Gautam V.
      • Dileepan S.
      • Rustagi N.
      • et al.
      Health literacy, preventive COVID 19 behaviour and adherence to chronic disease treatment during lockdown among patients registered at primary health facility in urban Jodhpur, Rajasthan.
      skills for occupation, and having a landline phone at home, computer and internet facility at home and work.
      • Ramasamy D.
      • Singh A.K.
      • Mohan S.K.
      Association of sociodemographics, technology use and health literacy among type 2 diabetic individuals living in an Indian setting: an exploratory cross-sectional study.
      Similarly, factors associated with inadequate HL were lower educational attainment,
      • Singh S.
      • Acharya S.D.
      • Kamath A.
      • Ullal S.D.
      • Urval R.P.
      Health literacy status and understanding of the prescription instructions in diabetic patients.
      ,
      • Ramasamy D.
      • Singh A.K.
      • Mohan S.K.
      Association of sociodemographics, technology use and health literacy among type 2 diabetic individuals living in an Indian setting: an exploratory cross-sectional study.
      inability to interpret medication instructions,
      • Singh S.
      • Acharya S.D.
      • Kamath A.
      • Ullal S.D.
      • Urval R.P.
      Health literacy status and understanding of the prescription instructions in diabetic patients.
      being female, unemployed, no landline phone at home, no computer, and internet facility at home and work,
      • Ramasamy D.
      • Singh A.K.
      • Mohan S.K.
      Association of sociodemographics, technology use and health literacy among type 2 diabetic individuals living in an Indian setting: an exploratory cross-sectional study.
      and poor diabetes knowledge.
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      Amongst the people with CVDs, the factors significantly associated with adequate HL were higher knowledge of CVDs,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      higher educational attainment,
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      ,
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      patients residing in urban areas,
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      and no history of re-vascularisation and medication adherence.
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      Inadequate HL was associated with low educational attainment,
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      ,
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.
      living in rural areas,
      • Shahzad F.
      • Saleem F.
      • Iqbal Q.
      • et al.
      A cross-sectional assessment of health literacy among hypertensive community of Quetta City, Pakistan.
      with poor knowledge of CVDs,
      • Shrestha A.
      • Singh S.B.
      • Khanal V.K.
      • Bhattarai S.
      • Maskey R.
      • Pokharel P.K.
      Health literacy and knowledge of chronic diseases in Nepal.
      histories of re-vascularisation, and medication non-adherence.
      • Suhail M.
      • Saeed H.
      • Saleem Z.
      • et al.
      Association of health literacy and medication adherence with health-related quality of life (HRQoL) in patients with ischemic heart disease.

      4. Discussion

      The evolving concept of HL is well recognised in improving health outcomes and quality of life among PLWNCDs. To our knowledge, this is the first review to present a comprehensive summary of the level of HL among PLWNCDs in South Asia.
      Our review shows that among people with diabetes, 26.00%-80.88% had inadequate HL and 9.00%–74.00% had adequate HL in the South Asian region. Prior studies from countries such as Malaysia (85.80%),
      • Azreena E.
      • Suriani I.
      • Juni M.H.
      • Fuziah P.
      Factors associated with health literacy among type 2 diabetes mellitus patients attending a government health clinic.
      Saudi Arabia
      • Mashi A.H.
      • Aleid D.
      • Almutairi S.
      • et al.
      The association of health literacy with glycemic control in Saudi patients with type 2 diabetes.
      and Ethiopia
      • Tefera Y.G.
      • Gebresillassie B.M.
      • Emiru Y.K.
      • et al.
      Diabetic health literacy and its association with glycemic control among adult patients with type 2 diabetes mellitus attending the outpatient clinic of a university hospital in Ethiopia.
      have reported a high prevalence of adequate HL among people with diabetes. This could be because the developing countries with better health care system provide quality care that may encourage patients to see their healthcare providers in need.
      • Abdullah A.
      • Ng C.J.
      • Liew S.M.
      • Ambigapathy S.
      • Paranthaman V.
      • Chinna K.
      Prevalence of limited health literacy and its associated factors in patients with type 2 diabetes mellitus in Perak, Malaysia: a cross-sectional study.
      The present review found that people with CVDs had inadequate HL (51.80%–83.43%).This finding is more than that reported in Iran
      • Chajaee F.
      • Pirzadeh A.
      • Hasanzadeh A.
      • Mostafavi F.
      Relationship between health literacy and knowledge among patients with hypertension in Isfahan province, Iran.
      and Thailand
      • Wannasirikul P.
      • Termsirikulchai L.
      • Sujirarat D.
      • Benjakul S.
      • Tanasugarn C.
      Health literacy, medication adherence, and blood pressure level among hypertensive older adults treated at primary health care centers.
      where people with CVDs had 49.00% and 48.70% inadequate HL, respectively. Intervention programs like education on disease and its risk factors, healthy diet, medication adherence by health professionals delivered through face-to-face, audiotapes mobile phone interventions (telephone calls, messages, and apps) to register fruits and vegetable consumption and handouts of health education materials were found to be effective in increasing the levels of HL.
      • Heine M.
      • Lategan F.
      • Erasmus M.
      • et al.
      Health education interventions to promote health literacy in adults with selected non‐communicable diseases living in low‐to‐middle income countries: a systematic review and meta‐analysis.
      • Visscher B.B.
      • Steunenberg B.
      • Heijmans M.
      • et al.
      Evidence on the effectiveness of health literacy interventions in the EU: a systematic review.
      • Barry M.M.
      • D'Eath M.
      • Sixsmith J.
      Interventions for improving population health literacy: insights from a rapid review of the evidence.
      In addition, good communication with individuals, more social engagement, and physical activity seem to be helpful in maintaining HL during aging.
      • Murman D.L.
      The impact of age on cognition.
      ,
      • Speros C.I.
      More than words: promoting health literacy in older adults.
      This review found two studies that measured HL among people with COPD. Almost three-quarters of the patients with COPD had inadequate HL. This finding aligns with the study conducted in Spain, with 58.78% having inadequate HL.
      • Puente-Maestu L.
      • Calle M.
      • Rodríguez-Hermosa J.L.
      • et al.
      Health literacy and health outcomes in chronic obstructive pulmonary disease.
      However, a study conducted in health care settings among people with COPD found a prevalence of 71.91%,
      • Kale M.S.
      • Federman A.D.
      • Krauskopf K.
      • et al.
      The association of health literacy with illness and medication beliefs among patients with chronic obstructive pulmonary disease.
      69.80%,
      • Muellers K.A.
      • Chen L.
      • O'Conor R.
      • Wolf M.S.
      • Federman A.D.
      • Wisnivesky J.P.
      Health literacy and medication adherence in COPD patients: when caregiver presence is not sufficient. COPD.
      and 67.43%
      • Agarwal P.
      • Lin J.
      • Muellers K.
      • et al.
      A structural equation model of relationships of health literacy, illness and medication beliefs with medication adherence among patients with chronic obstructive pulmonary disease.
      adequate HL in different parts of the U.S.A.
      This review found that various factors were determining HL among PLWNCDs. The common factors associated were educational attainment and knowledge of the disease and its risk factors. Our review found that higher educational attainment was associated with adequate HL, supported by previous studies.
      • Azreena E.
      • Suriani I.
      • Juni M.H.
      • Fuziah P.
      Factors associated with health literacy among type 2 diabetes mellitus patients attending a government health clinic.
      ,
      • Tefera Y.G.
      • Gebresillassie B.M.
      • Emiru Y.K.
      • et al.
      Diabetic health literacy and its association with glycemic control among adult patients with type 2 diabetes mellitus attending the outpatient clinic of a university hospital in Ethiopia.
      ,
      • Puente-Maestu L.
      • Calle M.
      • Rodríguez-Hermosa J.L.
      • et al.
      Health literacy and health outcomes in chronic obstructive pulmonary disease.
      ,
      • Ishikawa H.
      • Takeuchi T.
      • Yano E.
      Measuring functional, communicative, and critical health literacy among diabetic patients.
      The plausible explanation could be that people with higher educational attainment have a good cognitive level to understand and interpret the information and can take decisions to seek health services in need.
      • Alsous M.
      • Abdel Jalil M.
      • Odeh M.
      • Al Kurdi R.
      • Alnan M.
      Public knowledge, attitudes and practices toward diabetes mellitus: a cross-sectional study from Jordan.
      In addition, good knowledge of disease may increase people's confidence level, allowing them to communicate effectively and efficiently on their health issues with the health care providers.
      Furthermore, our review found that lower diabetes medication knowledge was associated with inadequate HL among people with diabetes. One study conducted among people with diabetes in Ethiopia found that inadequate HL leads to difficulty reading drug labels and medication prescriptions.
      • Tefera Y.G.
      • Gebresillassie B.M.
      • Emiru Y.K.
      • et al.
      Diabetic health literacy and its association with glycemic control among adult patients with type 2 diabetes mellitus attending the outpatient clinic of a university hospital in Ethiopia.
      Inadequate HL decreases medication self-efficacy among people,
      • Xu X.Y.
      • Leung A.Y.
      • Chau P.H.
      Health literacy, self-efficacy, and associated factors among patients with diabetes.
      , which increases the percentage of low medication adherence and has an adverse health outcome in people with diabetes.
      • Huang Y.M.
      • Shiyanbola O.O.
      • Smith P.D.
      Association of health literacy and medication self-efficacy with medication adherence and diabetes control.
      Further, unemployment and gender disparity, being female, was also significantly associated with inadequate HL. This result is in accordance with existing literature that found an association between inadequate HL with no or low socioeconomic conditions and being women.
      • Huang Y.M.
      • Shiyanbola O.O.
      • Smith P.D.
      Association of health literacy and medication self-efficacy with medication adherence and diabetes control.
      ,
      • Svendsen M.T.
      • Bak C.K.
      • Sørensen K.
      • et al.
      Associations of health literacy with socioeconomic position, health risk behavior, and health status: a large national population-based survey among Danish adults.
      Additionally, our review found that having a telephone, computer and internet facility at home and work was associated with adequate HL among people with diabetes, which is consistent with published evidence.
      • Svendsen M.T.
      • Bak C.K.
      • Sørensen K.
      • et al.
      Associations of health literacy with socioeconomic position, health risk behavior, and health status: a large national population-based survey among Danish adults.
      ,
      • Nacanabo R.
      • Debussche X.
      • Rouamba M.
      • Kamouni P.
      • Mancini J.
      • Kouanda S.
      Health literacy and health-related quality of life in type 2 diabetes: a cross-sectional study in Burkina Faso.
      The plausible reason could be that people often try to get health-related information through telephone consultation and the internet that might help them self-identify signs and symptoms of chronic disease early and encourage them to seek health care early.
      Similarly, our review found that people residing in urban areas had a higher prevalence of adequate HL than those residing in rural areas, which is congruent with the previous study.
      • Shiferaw K.B.
      • Tilahun B.C.
      • Endehabtu B.F.
      • Gullslett M.K.
      • Mengiste S.A.
      E-health literacy and associated factors among chronic patients in a low-income country: a cross-sectional survey.
      People in remote or rural areas have less access to education, employment opportunity, and healthcare facilities.
      • Finbråten H.S.
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      • Pettersen K.S.
      • Trollvik A.
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      Explaining variance in health literacy among people with type 2 diabetes: the association between health literacy and health behaviour and empowerment.
      These factors contributed to the poor HL of people.
      • Borges F.M.
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      • Almeida P.C.
      • Vieira N.F.
      • Machado A.L.
      Health literacy of adults with and without arterial hypertension.
      Another factor associated with inadequate HL was medication non-adherence, supported by a study in the U.S.A., where medication adherence was significantly lower among people with lower HL.
      • Aljassim N.
      • Ostini R.
      Health literacy in rural and urban populations: a systematic review.
      People with inadequate HL tend to have low medication knowledge,
      • Xie Y.
      • Ma M.
      • Zhang Y.N.
      • Tan X.
      Factors associated with health literacy in rural areas of Central China: structural equation model.
      because of which personal beliefs and actions might result in medication non-adherence.
      • Kripalani S.
      • Goggins K.
      • Nwosu S.
      • et al.
      Medication nonadherence before hospitalization for acute cardiac events.
      ,
      • Qin W.
      • Yu P.S.
      • Chen J.J.
      • Mehta G.
      • Kuo G.M.
      The effect of health literacy on medication knowledge and medication discrepancy in Chinese Americans.
      This review found other factors associated with HL among people with COPD. Low income was associated with inadequate HL, supported by previous research in the U.S.A., where education and income levels were associated with HL.
      • Abdou J.K.
      • Auyeung V.
      • Patel J.P.
      • Arya R.
      Adherence to long‐term anticoagulation treatment, what is known and what the future might hold.
      In addition to this, our review found that limited health literacy was associated with the female gender. A community-based study on HL found that inadequate HL on some domains of the HL tool was higher among females.
      • Fan J.H.
      • Lyons S.A.
      • Goodman M.S.
      • Blanchard M.S.
      • Kaphingst K.A.
      Relationship between health literacy and unintentional and intentional medication nonadherence in medically underserved patients with type 2 diabetes.
      However, prior studies from diverse communities in the USA have not found any significant association of limited HL with gender.
      • Kale M.S.
      • Federman A.D.
      • Krauskopf K.
      • et al.
      The association of health literacy with illness and medication beliefs among patients with chronic obstructive pulmonary disease.
      ,
      • Muellers K.A.
      • Chen L.
      • O'Conor R.
      • Wolf M.S.
      • Federman A.D.
      • Wisnivesky J.P.
      Health literacy and medication adherence in COPD patients: when caregiver presence is not sufficient. COPD.
      The association of inadequate HL among female and indigenous groups in this study might be because of gender disparity and less women empowerment. Studies from rural plains of Nepal showed that women and minor ethnic groups still fail to access health and education equally because of less autonomy in decision-making.
      • Omachi T.A.
      • Sarkar U.
      • Yelin E.H.
      • Blanc P.D.
      • Katz P.P.
      Lower health literacy is associated with poorer health status and outcomes in chronic obstructive pulmonary disease.
      ,
      • Beauchamp A.
      • Buchbinder R.
      • Dodson S.
      • et al.
      Distribution of health literacy strengths and weaknesses across socio-demographic groups: a cross-sectional survey using the Health Literacy Questionnaire (HLQ).
      A study by Kale et al. (2015) has found the association of inadequate or lower HL with minority groups,
      • Kale M.S.
      • Federman A.D.
      • Krauskopf K.
      • et al.
      The association of health literacy with illness and medication beliefs among patients with chronic obstructive pulmonary disease.
      consistent with our review where minority or vulnerable groups like Dalit and indigenous people with COPD had inadequate HL.

      4.1 Implication of the findings

      Our study findings may aid policymakers and researchers in conducting national health literacy research. This may guide the development and implementation of a people-centred comprehensive health literacy program for PLWNCDs to improve their health outcomes. Given that health literacy is an important social determinant of health, it is crucial to develop a contextual health literacy tool that can capture individuals’ capacity to obtain, process, and understand basic health information, skills to navigate the health care system, and ability to communicate with health care providers required to make appropriate health decisions. Moreover, the current review neither found any HL studies focusing on PLWNCDs from Afghanistan, Bhutan, Maldives, and Sri Lanka, which suggests the need for studies in these countries. Additionally, we could not find any studies that measured HL among chronic kidney disease patients in South Asian countries, which warrants future research.

      4.2 Limitations

      This review restricted the search to the English language and a few databases, because of which we anticipate missing some relevant articles. This review excluded information from grey literature and academic thesis. Besides these, the variation in the tools used in the studies caused a challenge for this review to pool the result statistically. Considering the above limitations, the magnitude of health literacy from our review should be cautiously interpreted as critical appraisal was not used while synthesising the findings.

      5. Conclusion

      The present review revealed limited HL among people with diabetes, cardiovascular and chronic obstructive pulmonary diseases in South Asia. Considering the findings from this review, we suggest the need for co-designing health promotion programs and strategies to improve HL among PLWNCDs in South Asia. Furthermore, the development of an appropriate contextual health literacy tool that can capture cultural, social and family influences on the health literacy of South Asian people.

      Author's contribution

      BK conceived the idea and designed the study under the supervision of UNY. BK, BR, and UNY screened eligible articles for full-text screening BK and BR drafted the manuscript. SKM, SP, and UNY contributed significantly to improving the quality of the manuscript. All authors read and approved the final manuscript.

      Source of funding

      The authors did not receive any funding for conducting this review.

      Declaration of competing interest

      The authors declare that no conflict of interest exists.

      Appendix A. Supplementary data

      The following is the Supplementary data to this article:

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