Adolescent undernutrition in South Asia: a scoping review protocol

Introduction The aim of the protocol is to present the methodology of a scoping review that aims to synthesise up-to-date evidence on adolescent undernutrition in South Asia. Methods and analysis The proposed scoping review will be guided by Arksey and O’Malley’s framework and the Joanna Briggs Institute Reviewers’ Manual. The scoping review question, eligibility criteria and search strategy will be based on the Population, Concept and Context strategy. We will conduct the search in electronic bibliographic databases (Medline (OVID), Embase, Cochrane Library, Web of Science, CINAHL, PsycInfo, Scopus) as well as various grey literature sources in order to synthesise and present the findings with descriptive statistics and a narrative description of both quantitative and qualitative evidence. Ethics and dissemination This study protocol does not require ethical approval. This protocol will accurately describe the proposed scoping review that will map the evidence on adolescent undernutrition in South Asia. The proposed review aims to gather published and unpublished literature to inform policy and healthcare organisations as well as identify future research priorities in South Asia.

ABSTRACT Introduction The aim of the protocol is to present the methodology of a scoping review that aims to synthesise up-to-date evidence on adolescent undernutrition in South Asia. Methods and analysis The proposed scoping review will be guided by Arksey and O'Malley's framework and the Joanna Briggs Institute Reviewers' Manual. The scoping review question, eligibility criteria and search strategy will be based on the Population, Concept and Context strategy. We will conduct the search in electronic bibliographic databases (Medline (OVID), Embase, Cochrane Library, Web of Science, CINAHL, PsycInfo, Scopus) as well as various grey literature sources in order to synthesise and present the findings with descriptive statistics and a narrative description of both quantitative and qualitative evidence. Ethics and dissemination This study protocol does not require ethical approval. This protocol will accurately describe the proposed scoping review that will map the evidence on adolescent undernutrition in South Asia. The proposed review aims to gather published and unpublished literature to inform policy and healthcare organisations as well as identify future research priorities in South Asia.

InTRoduCTIon
The most recent Global Nutrition Report highlights the global burden of malnutrition and that it remains unacceptably high affecting every country in the world. 1 The World Health Assembly formulated six global nutrition targets aiming to tackle the burden of malnutrition worldwide by 2025. 2 These targets plan to decrease stunting and wasting in children, reduce anaemia in women, decrease the rates of low birth weight, increase the rates of exclusive breastfeeding in the first 6 months and ensure that there is no increase in childhood overweight. Malnutrition refers to deficiencies, excesses or imbalances in a person's intake of energy and/or nutrients. 3 Focusing on early stages in life, the term malnutrition covers several conditions affecting child growth patterns such as stunting, wasting, underweight, micronutrient deficiencies and overweight/obesity. Stunting, or low height for age, is caused among other factors, by long-term insufficient nutrient intake, frequent infections and diseases. Wasting, or low weight for height, also indicates malnutrition prevalence among children under 5 years of age. While wasting is the result of acute significant food shortage and/or disease, stunting represents chronic malnutrition and the effects are largely irreversible. Underweight, or low weight for age, includes children under 5 with low weight for height (wasting) and low height for age (stunting) and considered a proxy indicator for undernutrition if data on wasting is not available. Micronutrient deficiencies or insufficiencies, also called 'hidden hunger', indicate a lack of important vitamins and minerals. Stunting, wasting, underweight and micronutrient deficiencies constitute the term 'undernutrition'. 3 Overweight/ obesity is another form of malnutrition that generally involves the development of noncommunicable diseases. Overweight/obesity are attributed to the term 'overnutrition'. 3 However, grown reference data and indicators are different between children and adolescents. The WHO recommends the use of BMI for age (thinness and overweight) and height for age (stunting) to explore adolescent growth patterns. 4 5 Stunting is defined as height-for-age<2 SDs below the WHO Child Growth Reference median. Overweight is defined as BMI-for-age>1 SD above the WHO Growth Reference median, and obesity is Table 1 Reviews on child and adolescent undernutrition in South Asia Akhtar 11 Mak 12 Pasricha 13 Khan 14 The proposed scoping review defined as >2 SDs above the WHO Growth Reference median. Thinness is defined as BMI-for-age<2 SDs below the WHO Growth Reference median. 5 The term thinness and underweight have been used interchangeably when making reference to adolescents' low BMI-for-age. 6 7 The State of food security and nutrition in the world reviewed the global prevalence of thinness among children aged 5-9 years and adolescents aged 10-19 years. 8 Thinness (BMI for age below 2 SD) in these age groups was associated with a higher risk of infectious diseases, delayed maturation, reduced muscular strength, work capacity and bone density later in life. In addition, thinness in adolescent girls was associated with adverse pregnancy outcomes and intrauterine growth retardation. Globally, 10% of children aged 5-19 have a BMI-for-age below 2 SD. There are significant differences in the prevalence of thinness among children aged 5-19 years by region of the world. For instance, the prevalence is high at >15% in South Asian countries such as India, Afghanistan, Bangladesh, Bhutan, Nepal, Pakistan and Sri Lanka in comparison to <2% in Latin America and the Caribbean, Northern America, Europe and Oceania. The global prevalence of thinness remained fairly steady over the past decade. 8 The prevalence of stunting (height for age below 2 SD), thinness (BMI for age below 2 SD) and overweight (BMI for age above 1 SD) were globally estimated using data from the Global School-Based Student Health and Health Behavior in School-Aged Children surveys conducted in 57 low and middle income countries between 2003 and 2013, involving 129 276 adolescents aged 12-15 years. 9 Globally, the prevalence of stunting was 10.2%, thinness was 5.5% and overweight 21.4%. Particularly in Pakistan, the prevalence of stunting was 7.1%, thinness was 11.2% and overweight 6.4% in 2009. In India in 2007, the prevalence of stunting was 14.6%, thinness was 15.9% and overweight 11.1%. In Sri Lanka in 2008, the prevalence of stunting was 25.6%, thinness was 31.5% and overweight 4.8%.
There are around of 1.8 billion adolescents worldwide and the majority are clustered in low-income and middleincome countries. 6 However, there is a gap in adolescent health data. 10 While the large global health and nutrition surveys mainly collected household data from adolescent girls aged ≥15 years; the 10-14-year-old age group, unmarried adolescents, unschooled adolescents and male adolescents have not been included in global health surveys. 10 Christian and Smith 6 highlighted the public health need to investigate adolescent nutrition deficiencies, growth and development.
Child and adolescent undernutrition in South Asia was previously reviewed [11][12][13][14] (see a summary of reviews in table 1). Some literature reviews 11 13 14 were focused on children, while Mak's systematic review 12 provided evidence on both children and adolescents. However, Mak's systematic review exclusively focused on studies examining the prevalence of underweight status in the last two decades. This scoping review protocol will include a larger pool of evidence by proposing a broader search strategy including micronutrient deficiencies as well as including grey literature without restrictions on date of publication.

REvIEw AIMS
The aim of this protocol is to describe the methodology of an up-to-date scoping review of the literature on adolescent undernutrition in South Asia and identifying gaps in knowledge. The proposed scoping review work could potentially be valuable to inform policy makers and healthcare organisations delivering adolescent health and nutrition actions in South Asia. It will constitute the first step in a larger research project aimed at improving adolescent health in Pakistan; these findings will inform the next quantitative and qualitative phases.

METhodS And AnAlySIS
All study types will be included to ensure the inclusion of the majority of relevant literature. 15 The design of the proposed scoping review methodology was informed by Arksey and O'Malley's framework 15 and The Joanna Briggs Institute Reviewers' Manual. 16 Arksey and O'Malley's methodological framework includes five stages to conduct a scoping review.

Stage 1: Identifying the research question
We will use the Population, Concept and Context (PCC) strategy to define the title, scoping review objective, scoping review question, and inclusion criteria. 16 Therefore, our main research question will address: adolescent undernutrition in South Asia, what do we know from the existing literature? Databases and search strategy An experienced research librarian (SJ) and one reviewer (SEQ) developed the search strategy by testing the keywords, MESH terms and databases to search. Finally, the reviewing team discussed and determined the final search strategy. The search will be conducted using the following electronic bibliographic databases and grey literature sources: Medline (OVID), Embase, Cochrane, Web of Science, CINAHL, PsycInfo, Scopus, the WHO Library Information System (WHOLIS), eLENA e-Library of Evidence for Nutrition Actions, and Opengrey. The websites of agencies, academic institutions and technical bodies will be also be searched: World Health Organisation (WHO), United Nations International Children's Emergency Fund (UNICEF), Demographic and Health Surveys (DHS), Program, Planning and Development Department AJ&K, Global Health Data Exchange (GHDx), World Food Program (WFP) and World Bank eLibrary. In addition, the topic field expert (RI) will be consulted to identify additional relevant grey literature sources. One reviewer (SEQ) will search additional resources by hand searching the references of included studies to identify further relevant evidence. This search strategy includes South Asia AND adolescents AND undernutrition. Related terms to undernutrition were also considered in the search strategy such as stunting, thinness, underweight and micronutrient deficiency. The search strategy was tailored to the specific requirements of each database. No restrictions on language or date of publication will be made. See full search strategy in online supplementary appendix 1.

Eligibility criteria
Despite the broadness of the proposed scoping review research question, the eligibility criteria should be clearly defined in order to thoroughly guide the reviewers' decisions. The inclusion criteria listed below are based on the PCC strategy: ► Population: adolescents mean age 10-19 years old. 17 ► Context: South Asia. The World Bank limits the South Asia region to Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka. 18 ► Concept: in this proposed scoping review only undernutrition indicators for adolescents will be used (stunting, thinness or underweight, and micronutrient deficiencies 3 ). Adolescent undernutrition will be assessed quantitatively using the following WHO indicators: (1) thinness or underweight (low BMIfor-age); (2) stunting (low height-for-age) and (3) micronutrient deficiencies. All studies will be included regardless of the growth references or cut-off values for micronutrients deficiency followed. ► Adolescent undernutrition in South Asia will also be assessed qualitatively, therefore qualitative studies exploring perspectives, experiences or opinions around adolescent undernutrition will be included. ► Type of studies: quantitative and qualitative studies as well as grey literature, for example, primary research studies, reviews, government reports and guidelines. Studies will be excluded if they include: ► Only overnutrition indicators (obesity and overweight). ► Pregnant or breastfeeding adolescents. ► Adolescent athletes. ► Adolescents with long term conditions such as diabetes, tuberculosis or HIV. ► Hospitalised adolescents. ► Intervention studies targeting treatment of a specific illness or condition such as diarrhoea.

Stage 3: Study selection
The screening process of this proposed scoping review will comprise two phases. First, titles and abstract will be reviewed by two independent reviewers following a broad inclusion criteria, that is, studies looking at adolescent undernutrition in South Asia. Papers identified by either or both reviewers will be included in the next phase, which is the full-text screening. The same reviewers will screen full-text studies using the eligibility criteria mentioned above. Disagreements will be resolved by either discussion Figure 1 Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram for scoping review process. Retrieved from Peters et al. 16 or referral to a third reviewer. Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram (see figure 1) will be presented to reflect the search process.
Stage 4: Charting the data Key characteristics to be extracted from the included studies will be extracted using a predefined dataextraction sheet. At this stage, one reviewer (SEQ) will conduct data extraction consisting of a summary table recording the key information of the selected studies (see box 1).

Stage 5: Collating, summarising and reporting the results
The results of the review will be reported as a map of the data extracted in a tabular form showing descriptive statistics. The tables may display the results as distribution of studies per year, geographical area where the study was conducted, location (community, hospital or school based), target population, outcomes and methods. In addition, a narrative description of both quantitative and qualitative results will accompany the descriptive presentation of the results by grouping the data into meaningful summaries for better exposition of the findings. For the qualitative studies, thematic analysis will be used to analyse the findings if data permits. Data will be exported into Nvivo and an inductive coding approach will be followed.

Patient and public involvement
No patient involved.