Systematic Review

Declining trend in anemia prevalence among non-pregnant women of reproductive age in Vietnam over two decades: A systematic review and meta-analysis of population studies

Introduction

In women, anaemia compromises health and well-being and raises the likelihood of unfavourable maternal and neonatal outcomes.¹ In 2019, the prevalence of anaemia in women of reproductive age was 29.9% (95% UI: 27.0-32.8), which is comparable to more than half a billion women aged 15-49 years worldwide.² Anaemia is a problem that affects the public health of developing nations, particularly among women and children. Anaemia has been linked to higher mortality and morbidity in women, stunted development in children, cognitive decline, an increased risk of infection of many sorts, and decreased productivity at work, all of which have a significant financial impact on families and the whole society.^3,4

Despite notable gains in socioeconomic and health status in the majority of low-income Southeast Asian nations, these countries continue to face challenges in lowering a high burden of malnutrition, which contributes to the high percentage of anaemia among non-pregnant women.⁵ The percentage of people who suffer from anaemia is on the decrease, falling from an estimated 39.8% in 1990 to an estimated 37.5% in 2010.⁶ Despite this, progress has been significantly less than predicted in lowering the percentage of anaemia, and its socio-economic impact, especially in resource-poor nations, remains a significant concern.⁶ In light of the slow progress that has been made in reducing the percentage of anaemia, the World Health Assembly in 2012 adopted a goal of a decrease in anaemia prevalence of 50% among women of reproductive age by the year 2025.^1,7 According to the worldwide prevalence of 29%–38% anaemia among women of reproductive age in 2011, achieving this aim would need a drop of 1.8%–2.4% points each year among this population.⁸

Vietnam, with a population of 98.51 million people and among those have 24.7 million women at reproductive age (15-49), is a developing nation in Southeast Asia.⁹ The reduction of anaemia in women of reproductive age is of critical importance to the protection and promotion of public health. This kind of information is required to identify the social and economic burden of anaemia and maximize the use of available medical resources to enhance anaemia’s diagnosis, treatment, and prevention. In Vietnam, several population-based studies representative of a single region/province have been carried out throughout the last two decades; nevertheless, there is no estimate of the prevalence over the whole nation or of the trend during this period. Therefore, we performed a systematic literature review and meta-analysis to provide a comprehensive and up-to-date evaluation of the prevalence of anaemia among non-pregnant women in Vietnam.

Material and Methods

This systematic review and meta-analysis project was carried out in accordance with the protocol that had been published and submitted to the International Prospective Register of Systematic Reviews. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards were adhered to throughout this meta-analysis and systematic review.¹⁰

Search procedure

A comprehensive search of the scholarly literature was carried out in order to locate prospective publications that had been published on the frequency of anaemia among the population of reproductive women in Vietnam. PubMed and Scopus databases were carefully searched in July 06, 2022 with no time constraint. A list of search techniques was compiled by the search team, which included the following keywords: “Vietnam”, “Vietnamese”, “Women”, “Adult”, “Non-pregnancy”, “Anemia”, “Anaemia”, “Haemoglobin”, “Hemoglobin”, “Haematocrit”, “Hematocrit”. After settling on a list of pertinent keywords, database searches were conducted using those keywords, using the “AND” and “OR” operators chained together as necessary. The following PubMed and Scopus advanced search options were employed: “(Vietnam[Title/Abstract] OR Vietnamese[Title/Abstract]) AND (Women[Title/Abstract] OR Adult[Title/Abstract] OR non-pregnancy[Title/Abstract]) AND (anemia[Title/Abstract] OR anaemia[Title/Abstract] OR haemoglobin[Title/Abstract] OR hemoglobin[Title/Abstract] OR haematocrit[Title/Abstract] OR hematocrit[Title/Abstract])”, and “TITLE ((vietnam OR vietnamese) AND (women OR adult OR non-pregnancy) AND (anemia OR anaemia OR haemoglobin OR hemoglobin OR haematocrit OR hematocrit)) TITLE-ABS-KEY (((vietnam OR vietnamese ) AND (women OR adult OR non-pregnancy) AND (anemia OR anaemia OR haemoglobin OR hemoglobin OR haematocrit OR hematocrit))) respectively. There were no linguistic limitations. In addition, we combed through the reference lists of significant publications to identify possibly relevant other articles.

Selection of studies

Using the inclusion criteria, two separate researchers evaluated the eligibility of all abstracts retrieved from our searches after a preliminary assessment of the titles acquired. In the case of dispute among reviewers, a third reviewer evaluated the research and a decision for inclusion were made by unanimous consent.

Inclusion criteria

The following criteria were used for inclusion:

• Population: the research involved non-pregnant women of reproductive age (15-49 years).

• Study area: The study was only conducted in Vietnam.

• Study design: The article must fulfill all of the following prerequisites for inclusion: (1) was an original study or national survey; (2) was able to determine the prevalence of anaemia for the non-pregnant women of reproductive age; and (3) comprised a survey of either the general population or the community at large.

• Publication condition: the article (1) was written in English, and (2) was published in a peer-reviewed journal.

Exclusion criteria

The studies were disqualified based on the criteria listed below:

• Research on the prevalence of anaemia in certain groups, such as those suffering from cancer, HIV/AIDS, dengue, renal disease, diabetes, and pregnant and postpartum women.

• Animal-based research.

• Review articles, case studies, letters, commentaries, protocols, conference abstracts and case-control studies.

• Methodologically flawed articles.

• Duplicated studies or duplicate populations from another research included in the review. Only one of these studies had the most significant population sample to be included in our overall prevalence estimate.

Data extraction

Data was gathered from a selection of articles by three separate authors (TQD, BTTT and DTPH) based on criteria that were previously established. These researchers then went through each full-text study to determine its eligibility. For each study found to be eligible, data were extracted separately using Microsoft Excel 2019 for macOS. The following information was gleaned from the retrieved full-text article: the full name of the first author and year of publication, study design and period, sample size, geographic (mountain/plain), areas (urban/rural), regions (Northern/Central/Southern Vietnam), partial or complete ethnic minority participation (yes/no) and percentage of participants with anaemia. All authors participated in a conversation to resolve any discrepancies in the data extraction procedure.

Qualitative evaluation of studies

Using an adapted version of the Newcastle-Ottawa Scale that was designed specifically for use in cross-sectional and case-control studies,¹¹ three authors (NTK, TQD and PNQ) independently evaluated the degree of methodological rigor present in each of the included studies. This standardized tool includes three primary indications pertaining to the methodological characteristics, the comparability, and the statistical analysis of publications. According to the list of questions provided for each indication, the authors must choose the most appropriate answer for the included article in question. A score was only given to an answer that demonstrated high quality. We divided the overall quality of each included study into four categories, as follows: very good studies (8 to 9 points), good studies (6 to 7 points), satisfactory studies (4 to 5 points) and unsatisfactory studies (0 to 3 points). The final analysis did not include any unsatisfactory studies. The online appendix file may include details on how the final scores were calculated.

Statistical analysis

After the data extraction process was completed using the Microsoft Excel program, the data were then exported to the RStudio Desktop 2022.07.0 + 548 version software for macOS 10.15 + (https://posit.co/download/rstudio-desktop/). The meta-analyses were conducted using ‘meta’, ‘metafor’, and ‘ggplot2’ packages. The I² statistic was used to determine the degree of heterogeneity between included studies.¹² It was anticipated that the I² would be high, and the prevalence of anaemia could dissimilarity between studies due to genuine differences in the characteristics of included studies and the potential factors (e.g. various collecting periods, socio-economic circumstances, and dietary habits in different geographic regions) that might affect the anaemia condition of Vietnamese non-pregnant women of reproductive age. Consequently, viewed from these angles, we estimated the pooled prevalence using a random-effects model with a 95% confidence interval (CI). Subgroup analyses were performed by period, design, sampling, geographics, areas, regions and ethnic minority participation in the included studies. To investigate publication bias, we analyzed the symmetry of the funnel plots and used the Egger’s regression test; P < 0.10 was judged statistically significant. We also did a sensitivity analysis, in which we excluded one research at a time, to elucidate the impact of individual studies on the overall pooled estimate and to determine influential studies.

Results

presents a summary of the number of studies that were found, reviewed, and ultimately included in our research using the PRISMA flow diagram. The initial literature search yielded a total of 188 possible articles. Out of these, 74 duplicate articles were eliminated; 28 of them were then omitted from further analysis because, based on their titles, they did not fit the inclusion requirements. Thus, only 86 research papers were selected for abstract and full-text evaluation. The graphical representation of the textual explanations for retrieved but not included articles were displayed. Of the 74 excluded publications reviewed, one¹³ was discarded because it did not give sufficient information regarding sample size, participant selection, and comparisons between groups, even though fulfilling the requirements for inclusion. Following an in-depth evaluation, the quantitative synthesis includes a total of 12 different papers that were published between the years 2003 and 2017.^14-25

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Figure 1. A graphical depiction of the search for relevant literature to include in the meta-analysis

Included study characteristics

Table 1 shows the characteristics of the included studies. There were a total of 19 744 women of reproductive age who had their anaemia checked with the number of participants in each research varies anywhere from 72¹⁵ to 6774,²⁰ and the data from the included researches were collected from 1995²⁰ to 2013.¹⁸ The majority of research used cross-sectional designs and random sampling as their primary data collection methods. Most of the research was done in two regions of Vietnam. Among them are one research from the Central Vietnam region,¹⁶ nine studies from the Northern Vietnam region,^{14,15,17-19,21,23-25} one national study,²⁰ and one study on a large-scale.²² Additionally, there were six studies from plain areas,^{14,15,17,21,23,25} four studies from mountain areas,^16,18,19,24 and one study from both plain and mountain areas.²² Haemoglobin (Hb) values below 12.0 g/dL or 120 g/L were utilized for all included studies as the diagnostic threshold for anaemia among non-pregnant women of reproductive-aged 15–49 years old. It has been observed that the prevalence of anaemia in non-pregnant women ranges from 9.3%¹⁷ to 45.6%,²⁵ with the greatest and lowest values correspondingly. Only one of the articles has obtained the minimum score required for inclusion on the quality evaluation scale¹⁵; the other articles all have scores of 8 or above. The score of each included article is shown in Table 1.

Pooled meta-analysis

In a total sample of 19 744 non-pregnant women, the pooled prevalence of anaemia was 23.2% (Q = 1549.93; df = 11; P< 0.001; 95% CI: 16.1-32.2, I² = 99.29%, based on 12 studies). Because there was statistically significant heterogeneity among the included publications, we utilized a random effect meta-analysis approach to estimate the pooled prevalence of anaemia among non-pregnant Vietnamese women. depicts a forest plot of the prevalence estimates with their associated CIs. In the sensitivity analysis, no single included study significantly impacted the overall pooled prevalence of anaemia, indicating the remarkable consistency of the finding (Table 2). The funnel plot, shown in , revealed that there was almost no publication bias, and the results of the Egger regression test (P = 0.9081) strongly supported this conclusion.

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Figure 2. Pooled anaemia percentage among 19,744 non-pregnant women in Vietnam

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Figure 3. Funnel plot of the prevalence of anaemia among non-pregnant Vietnamese women

After recognizing the studies’ heterogeneity, subgroup analysis was performed based on several characteristics. As Table 3 summarizes, analyses by study design revealed that case-control studies indicated a slightly higher significance in the pooled prevalence of anaemia than cross-sectional studies (25.4%; 95% CI: 16.0-37.9 vs 21.9%; 95%: 14.9-31.1). The prevalence of anaemia was more common in studies that used a non-random sample method (37.5%; 95% CI: 7.1-49.2) than in studies that used a random sampling method (22.1%; 95% CI:16.2-29.5). Regarding the ethnic minority demographic, studies that included ethnic minorities in some or all of their participants had a significantly higher prevalence of anaemia (25.1%; 95% CI: 14.7-39.4) than studies that did not include individuals from an ethnic minority (22.5%, 95% CI: 15.8-31.1).

In terms of geographics, regions, and areas, the prevalence of anaemia in Vietnam women was shown to be relatively greater in studies that were carried out in the mountains, in Northern Vietnam, and in rural areas (27.7%; 95% CI: 17.7-40.5, 23.7%; 95% CI: 17.4-31.4 and 28.7%; 95% CI: 21.0-37.8, respectively) than in studies conducted in the plains, in Central Vietnam, and in urban areas of Vietnam (20.6%; 95% CI: 13.9-29.5, 19.9%; 95% CI: 15.5-25.0, 9.4%; 95% CI: 4.4-18.9, respectively).

Anaemia prevalence was stratified by collecting periods: before 2000, 2000-2005, and after 2005 (). The prevalence of anaemia was 42.6% (25.0-62.3), 23.5% (15.4-34.1) and 16.9% (10.8-25.4), accordingly to the times during which collections were made. From 1995 to 2013, the pool prevalence of anaemia decreased from 42.6% to 16.9%, a significant reduction.

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Figure 4. A box plot depicting the decreasing prevalence of anaemia among non-pregnant Vietnamese women over roughly two decades

Discussion

In this comprehensive systematic review, which included a meta-analysis of cross-sectional and case-control surveys carried out in Vietnam over the past two decades and involving 19,744 non-pregnant women of reproductive age, it was possible to arrive at accurate estimates of the prevalence of anaemia in this population. With the WHO anaemia cut point of 12.00 g/dL for non-pregnant women, the findings of this meta-analysis encompassing 12 articles revealed that the prevalence of anaemia in this demographic in Vietnam was 23.2% (95% CI: 16.1-32.2). This review also revealed a nearly two-decade-long decline in the prevalence of anaemia among women in Vietnam. According to the WHO categorization of public health significance of anaemia in communities, the percentage of anaemia in women of reproductive age in Vietnam is at the second most hazardous level (Moderate).²⁶

Compared to the findings from other countries in seven South and Southeast Asian nations,²⁷ our finding was significant lower (23.2% vs 52.6%). The differences in diet, geography, and culture between Vietnam and these nations might be a probable explanation for the disparity in anaemia.²⁸ The first national nutrition plan to be formally recognized in Vietnam was ratified by the Prime Minister in 1995 and titled the National Plan of Action for Nutrition 1995-2000. Several interventions were then in place in Vietnam to fight anaemia in reproductive-age women using integrated, multifactorial, and multisectoral approaches, which recognizes the complexities of anaemia and may lead to beneficial methods. The execution of the National Plan of Action for Nutrition (1995-2000), advocacy and other communication initiatives to boost food production and consumption in Vietnam during the last decade has been effective. The recent decade has seen an increase in the production of the most important foods. Dietary intake has increased significantly compared to 1987, with more people consuming higher-quality meals, including meat, fish, fat oils, and ripe fruits.²⁹ The National Nutrition Strategies for 2001-2010 and 2011-2020 were developed as the following official document controlling nutrition policy in Vietnam as a follow-up to the first National Plan, which served as the official document regulating nutrition policy in Vietnam at the time. The nutrition status of the Vietnamese people, in general, has significantly improved after more than twenty years of implementing these National Plans with comprehensive approaches, multi-sector cooperation, and government guidance at different levels. This improvement coincides with increasing awareness of nutrition issues among the Vietnamese.³⁰ Notably, even though many parts of Vietnam have seen general improvements in lowering the prevalence of anaemia, our findings highlight persistent disparities across mountains, in Northern Vietnam, in rural areas and ethnic minority groups that have either remained unchanged or fallen behind the general improvements of other locations within the country. We presume that our results are consistent with the result of Harris et al³¹ that although Vietnam has effectively decreased population stunting, ethnic minority groups are being systematically left behind, hindering progress toward national reductions.^31,32 The rationale suggested for this predicament is that government policies and initiatives may not have been culturally adaptive and responsive, and there have been allegations of negative attitudes and prejudice by health workers toward minorities.³³ In addition, a significant portion of Vietnam’s officially recognized ethnic minority groups is finding that they are unable to properly interact with the programs developed for their respective areas by the central government.³¹

There are, however, further significant gaps in the research about the prevalence of non-pregnant Vietnamese women that need to be addressed. First, when the data were pooled, a substantial amount of heterogeneity was discovered. One possible explanation for this heterogeneity is that the studies that were identified had distinct features and unexamined factors. Second, because the data were only available for research carried out in Northern and Central Vietnam, the ability to generalize the findings to Southern Vietnam may be restricted. Third, since meta-analysis by its very nature utilizes aggregated group data, other confounding factors that may have an influence on the prevalence of anaemia were not considered and excluded, and this may have caused the estimate to be inaccurate. Fourth, we regret that due to limited access to subscription databases at developing country universities, we were unable to study any of the other databases, which may have resulted in publication bias. Strikingly, our findings reflect the best estimations that are presently available and might serve as a point of reference for further designing policies pertaining to public health. We conclude that our searches of the PubMed and Scopus databases were sufficient since our research objective is limited to studies on the anaemia percentage. Finally, due to our research primarily focused on the general population, the pooled estimate for the prevalence of anaemia among Vietnamese women may not accurately reflect the extent of the problem in other specialized populations.

Conclusion

To our knowledge, this was the first systematic study to assess the pooled prevalence of anaemia among non-pregnant women of reproductive age in Vietnam during the past two decades. This population in Vietnam is showing a decreasing trend in the prevalence of anaemia as a result of our comprehensive research. The data also highlights disparities in geographical and ethnic minority groups in the prevalence of anaemia among non-pregnant women of reproductive age. The larger proportion is seen in the highlands, Northern Vietnam and rural areas. Efforts to combat ethnic health disparities should concentrate on high-risk groups by establishing control and preventative techniques that address anaemia’s socio-cultural and dietary specificities in indigenous populations.

Author Contributions

Conceptualization: Nguyen Trung Kien and Tran Quang Duc.

Data curation: Tran Quang Duc.

Formal Analysis: Nguyen Trung Kien and Tran Quang Duc.

Funding acquisition: None.

Investigation: Bui Thi Thanh Tuyen and Dinh Thi Phuong Hoa.

Methodology: Nguyen Trung Kien and Tran Quang Duc.

Project administration: Vu Thi Quynh Chi and Bui Thi Thanh Tuyen

Resources: Tran Quang Duc.

Software: Tran Quang Duc and Phan Ngoc Quang.

Supervision: Nguyen Trung Kien.

Validation: Nguyen Trung Kien, Tran Quang Duc and Phan Ngoc Quang.

Visualization: Tran Quang Duc and Vu Thi Quynh Chi.

Writing – original draft: Tran Quang Duc and Bui Thi Thanh Tuyen.

Writing – review & editing: Vu Thi Quynh Chi and Phan Ngoc Quang.

Funding

Nil.

Ethical Approval

Not required.

Competing Interests

There are no conflicts of interest.

References

1. . Global Nutrition Targets 2025: Anaemia Policy Brief (WHO/NMH/NHD/14.4) 2014.
2. World Health Organization (WHO). WHO Global Anaemia Estimates, 2021 Edition. Anaemia in Women and Children. 2021. Available from: https://www.who.int/data/gho/data/themes/topics/anaemia_in_women_and_children. Accessed February 18, 2022.
3. Anaemia in low-income and middle-income countries. Lancet 2011; 378(9809):2123-35. doi: 10.1016/s0140-6736(10)62304-5 [Crossref]
4. Maternal and child undernutrition and overweight in low-income and middle-income countries. Lancet 2013; 382(9890):427-51. doi: 10.1016/s0140-6736(13)60937-x [Crossref]
5. Nutrition-specific interventions for preventing and controlling anaemia throughout the life cycle: an overview of systematic reviews. Cochrane Database Syst Rev 2021; 9(9):CD013092. doi: 10.1002/14651858.CD013092.pub2 [Crossref]
6. A systematic analysis of global anemia burden from 1990 to 2010. Blood 2014; 123(5):615-24. doi: 10.1182/blood-2013-06-508325 [Crossref]
7. World Health Organization (WHO). Comprehensive Implementation Plan on Maternal, Infant and Young Child Nutrition. WHO; 2014.
8. Anemia epidemiology, pathophysiology, and etiology in low- and middle-income countries. Ann N Y Acad Sci 2019; 1450(1):15-31. doi: 10.1111/nyas.14092 [Crossref]
9. . Average Population by Location 2021.
10. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. BMJ 2009; 339:b2535. doi: 10.1136/bmj.b2535 [Crossref]
11. Wells GA, Shea B, O’Connell D, Peterson J, Welch V, Losos M, et al. The Newcastle-Ottawa Scale (NOS) for Assessing the Quality of Nonrandomised Studies in Meta-Analyses. 2015. Available from: https://www.ohri.ca/programs/clinical_epidemiology/oxford.asp. Accessed 10 November 2022.
12. Higgins JP, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, et al. Cochrane Handbook for Systematic Reviews of Interventions. John Wiley & Sons; 2019.
13. Soil-transmitted helminth infection and its association with anemia and zinc deficiency among women in Nghe An province, Vietnam. Iran J Parasitol 2019; 14(1):180-2.
14. The use of NaFeEDTA-fortified fish sauce is an effective tool for controlling iron deficiency in women of childbearing age in rural Vietnam. J Nutr 2005; 135(11):2596-601. doi: 10.1093/jn/135.11.2596 [Crossref]
15. Serum levels of trace elements and iron-deficiency anemia in adult Vietnamese. Biol Trace Elem Res 2006; 111(1-3):1-9. doi: 10.1385/bter:111:1:1 [Crossref]
16. Sustained effectiveness of weekly iron-folic acid supplementation and regular deworming over 6 years in women in rural Vietnam. PLoS Negl Trop Dis 2017; 11(4):e0005446. doi: 10.1371/journal.pntd.0005446 [Crossref]
17. Community mobilization and social marketing to promote weekly iron-folic acid supplementation in women of reproductive age in Vietnam: impact on anemia and iron status. Nutr Rev 2005; 63(12 Pt 2):S95-108. doi: 10.1301/nr.2005.dec.s95-s108 [Crossref]
18. Anaemia in pregnant, postpartum and non pregnant women in Lak district, Daklak province of Vietnam. Asia Pac J Clin Nutr 2007; 16(2):310-5.
19. Regular consumption of NaFeEDTA-fortified fish sauce improves iron status and reduces the prevalence of anemia in anemic Vietnamese women. Am J Clin Nutr 2003; 78(2):284-90. doi: 10.1093/ajcn/78.2.284 [Crossref]
20. Neither preconceptional weekly multiple micronutrient nor iron-folic acid supplements affect birth size and gestational age compared with a folic acid supplement alone in rural Vietnamese women: a randomized controlled trial. J Nutr 2016; 146(7):1445S-52S. doi: 10.3945/jn.115.223420 [Crossref]
21. Baseline iron indices as predictors of hemoglobin improvement in anemic Vietnamese women receiving weekly iron-folic acid supplementation and deworming. Am J Trop Med Hyg 2009; 81(6):1114-9. doi: 10.4269/ajtmh.2009.09-0162 [Crossref]
22. Risk factors for anemia in Vietnam. Southeast Asian J Trop Med Public Health 2006; 37(6):1213-23.
23. Difructose anhydride III enhances bioavailability of water-insoluble iron in anemic Vietnamese women. J Nutr Sci Vitaminol (Tokyo) 2010; 56(3):191-7. doi: 10.3177/jnsv.56.191 [Crossref]
24. Intra-individual double burden of overweight and micronutrient deficiencies among Vietnamese women. PLoS One 2014; 9(10):e110499. doi: 10.1371/journal.pone.0110499 [Crossref]
25. An animal-source food supplement increases micronutrient intakes and iron status among reproductive-age women in rural Vietnam. J Nutr 2017; 147(6):1200-7. doi: 10.3945/jn.116.241968 [Crossref]
26. World Health Organization (WHO). Haemoglobin Concentrations for the Diagnosis of Anaemia and Assessment of Severity. WHO; 2011.
27. Prevalence and factors associated with anemia among women of reproductive age in seven South and Southeast Asian countries: evidence from nationally representative surveys. PLoS One 2020; 15(8):e0236449. doi: 10.1371/journal.pone.0236449 [Crossref]
28. Determining factors for the prevalence of anemia in women of reproductive age in Nepal: evidence from recent national survey data. PLoS One 2019; 14(6):e0218288. doi: 10.1371/journal.pone.0218288 [Crossref]
29. Trends in food production and food consumption in Vietnam during the period 1980-2000. Malays J Nutr 2003; 9(1):1-5.
30. The cost of implementing Vietnam’s national plan of action for nutrition for 2017-2020. AIMS Public Health 2019; 6(3):276-90. doi: 10.3934/publichealth.2019.3.276 [Crossref]
31. Nobody left behind? Equity and the drivers of stunting reduction in Vietnamese ethnic minority populations. Food Secur 2021; 13(4):803-18. doi: 10.1007/s12571-021-01183-7 [Crossref]
32. Vietnam National Institute of Nutrition. National Nutrition Strategy for 2011-2020, With a Vision Toward 2030. Hanoi: Medical Publishing House; 2012.
33. Ethnic minority health in Vietnam: a review exposing horizontal inequity. Glob Health Action 2013; 6:1-19. doi: 10.3402/gha.v6i0.19803 [Crossref]