Community-level interventions for improving access to food in low- and middle-income countries.

BACKGROUND: After decades of decline since 2005, the global prevalence of undernourishment reverted and since 2015 has increased to levels seen in 2010 to 2011. The prevalence is highest in low- and middle-income countries (LMICs), especially Africa and Asia. Food insecurity and associated undernutrition detrimentally affect health and socioeconomic development in the short and long term, for individuals, including children, and societies. Physical and economic access to food is crucial to ensure food security. Community-level interventions could be important to increase access to food in LMICs. OBJECTIVES: To determine the effects of community-level interventions that aim to improve access to nutritious food in LMICs, for both the whole community and for disadvantaged or at-risk individuals or groups within a community, such as infants, children and women; elderly, poor or unemployed people; or minority groups. SEARCH METHODS: We searched for relevant studies in 16 electronic databases, including trial registries, from 1980 to September 2019, and updated the searches in six key databases in February 2020. We applied no language or publication status limits. SELECTION CRITERIA: We included randomised controlled trials (RCTs), cluster randomised controlled trials (cRCTs) and prospective controlled studies (PCS). All population groups, adults and children, living in communities in LMICs exposed to community-level interventions aiming to improve food access were eligible for inclusion. We excluded studies that only included participants with specific diseases or conditions (e.g. severely malnourished children). Eligible interventions were broadly categorised into those that improved buying power (e.g. create income-generation opportunities, cash transfer schemes); addressed food prices (e.g. vouchers and subsidies); addressed infrastructure and transport that affected physical access to food outlets; addressed the social environment and provided social support (e.g. social support from family, neighbours or government). DATA COLLECTION AND ANALYSIS: Two authors independently screened titles and abstracts, and full texts of potentially eligible records, against the inclusion criteria. Disagreements were resolved through discussion or arbitration by a third author, if necessary. For each included study, two authors independently extracted data and a third author arbitrated disagreements. However, the outcome data were extracted by one author and checked by a biostatistician. We assessed risk of bias for all studies using the Effective Practice and Organization of Care (EPOC) risk of bias tool for studies with a separate control group. We conducted meta-analyses if there was a minimum of two studies for interventions within the same category, reporting the same outcome measure and these were sufficiently homogeneous. Where we were able to meta-analyse, we used the random-effects model to incorporate any existing heterogeneity. Where we were unable to conduct meta-analyses, we synthesised using vote counting based on effect direction. MAIN RESULTS: We included 59 studies, including 214 to 169,485 participants, and 300 to 124, 644 households, mostly from Africa and Latin America, addressing the following six intervention types (three studies assessed two different types of interventions). Interventions that improved buying power: Unconditional cash transfers (UCTs) (16 cRCTs, two RCTs, three PCSs): we found high-certainty evidence that UCTs improve food security and make little or no difference to cognitive function and development and low-certainty evidence that UCTs may increase dietary diversity and may reduce stunting. The evidence was very uncertain about the effects of UCTs on the proportion of household expenditure on food, and on wasting. Regarding adverse outcomes, evidence from one trial indicates that UCTs reduce the proportion of infants who are overweight. Conditional cash transfers (CCTs) (nine cRCTs, five PCSs): we found high-certainty evidence that CCTs result in little to no difference in the proportion of household expenditure on food and that they slightly improve cognitive function in children; moderate-certainty evidence that CCTs probably slightly improve dietary diversity and low-certainty evidence that they may make little to no difference to stunting or wasting. Evidence on adverse outcomes (two PCSs) shows that CCTs make no difference to the proportion of overweight children. Income generation interventions (six cRCTs, 11 PCSs): we found moderate-certainty evidence that income generation interventions probably make little or no difference to stunting or wasting; and low-certainty evidence that they may result in little to no difference to food security or that they may improve dietary diversity in children, but not for households. Interventions that addressed food prices: Food vouchers (three cRCTs, one RCT): we found moderate-certainty evidence that food vouchers probably reduce stunting; and low-certainty evidence that that they may improve dietary diversity slightly, and may result in little to no difference in wasting. Food and nutrition subsidies (one cRCT, three PCSs): we found low-certainty evidence that food and nutrition subsidies may improve dietary diversity among school children. The evidence is very uncertain about the effects on household expenditure on healthy foods as a proportion of total expenditure on food (very low-certainty evidence). Interventions that addressed the social environment: Social support interventions (one cRCT, one PCS): we found moderate-certainty evidence that community grants probably make little or no difference to wasting; low-certainty evidence that they may make little or no difference to stunting. The evidence is very uncertain about the effects of village savings and loans on food security and dietary diversity. None of the included studies addressed the intervention category of infrastructure changes. In addition, none of the studies reported on one of the primary outcomes of this review, namely prevalence of undernourishment. AUTHORS' CONCLUSIONS: The body of evidence indicates that UCTs can improve food security. Income generation interventions do not seem to make a difference for food security, but the evidence is unclear for the other interventions. CCTs, UCTs, interventions that help generate income, interventions that help minimise impact of food prices through food vouchers and subsidies can potentially improve dietary diversity. UCTs and food vouchers may have a potential impact on reducing stunting, but CCTs, income generation interventions or social environment interventions do not seem to make a difference on wasting or stunting. CCTs seem to positively impact cognitive function and development, but not UCTs, which may be due to school attendance, healthcare visits and other conditionalities associated with CCTs.

Community-level interventions for improving access to food in low- and middle-income countries.

BACKGROUND: After decades of decline since 2005, the global prevalence of undernourishment reverted and since 2015 has increased to levels seen in 2010 to 2011. The prevalence is highest in low- and middle-income countries (LMICs), especially Africa and Asia. Food insecurity and associated undernutrition detrimentally affect health and socioeconomic development in the short and long term, for individuals, including children, and societies. Physical and economic access to food is crucial to ensure food security. Community-level interventions could be important to increase access to food in LMICs. OBJECTIVES: To determine the effects of community-level interventions that aim to improve access to nutritious food in LMICs, for both the whole community and for disadvantaged or at-risk individuals or groups within a community, such as infants, children and women; elderly, poor or unemployed people; or minority groups. SEARCH METHODS: We searched for relevant studies in 16 electronic databases, including trial registries, from 1980 to September 2019, and updated the searches in six key databases in February 2020. We applied no language or publication status limits. SELECTION CRITERIA: We included randomised controlled trials (RCTs), cluster randomised controlled trials (cRCTs) and prospective controlled studies (PCS). All population groups, adults and children, living in communities in LMICs exposed to community-level interventions aiming to improve food access were eligible for inclusion. We excluded studies that only included participants with specific diseases or conditions (e.g. severely malnourished children). Eligible interventions were broadly categorised into those that improved buying power (e.g. create income-generation opportunities, cash transfer schemes); addressed food prices (e.g. vouchers and subsidies); addressed infrastructure and transport that affected physical access to food outlets; addressed the social environment and provided social support (e.g. social support from family, neighbours or government). DATA COLLECTION AND ANALYSIS: Two authors independently screened titles and abstracts, and full texts of potentially eligible records, against the inclusion criteria. Disagreements were resolved through discussion or arbitration by a third author, if necessary. For each included study, two authors independently extracted data and a third author arbitrated disagreements. However, the outcome data were extracted by one author and checked by a biostatistician. We assessed risk of bias for all studies using the Effective Practice and Organization of Care (EPOC) risk of bias tool for studies with a separate control group. We conducted meta-analyses if there was a minimum of two studies for interventions within the same category, reporting the same outcome measure and these were sufficiently homogeneous. Where we were able to meta-analyse, we used the random-effects model to incorporate any existing heterogeneity. Where we were unable to conduct meta-analyses, we synthesised using vote counting based on effect direction. MAIN RESULTS: We included 59 studies, including 214 to 169,485 participants, and 300 to 124, 644 households, mostly from Africa and Latin America, addressing the following six intervention types (three studies assessed two different types of interventions). Interventions that improved buying power: Unconditional cash transfers (UCTs) (16 cRCTs, two RCTs, three PCSs): we found high-certainty evidence that UCTs improve food security and make little or no difference to cognitive function and development and low-certainty evidence that UCTs may increase dietary diversity and may reduce stunting. The evidence was very uncertain about the effects of UCTs on the proportion of household expenditure on food, and on wasting. Regarding adverse outcomes, evidence from one trial indicates that UCTs reduce the proportion of infants who are overweight. Conditional cash transfers (CCTs) (nine cRCTs, five PCSs): we found high-certainty evidence that CCTs result in little to no difference in the proportion of household expenditure on food and that they slightly improve cognitive function in children; moderate-certainty evidence that CCTs probably slightly improve dietary diversity and low-certainty evidence that they may make little to no difference to stunting or wasting. Evidence on adverse outcomes (two PCSs) shows that CCTs make no difference to the proportion of overweight children. Income generation interventions (six cRCTs, 11 PCSs): we found moderate-certainty evidence that income generation interventions probably make little or no difference to stunting or wasting; and low-certainty evidence that they may result in little to no difference to food security or that they may improve dietary diversity in children, but not for households. Interventions that addressed food prices: Food vouchers (three cRCTs, one RCT): we found moderate-certainty evidence that food vouchers probably reduce stunting; and low-certainty evidence that that they may improve dietary diversity slightly, and may result in little to no difference in wasting. Food and nutrition subsidies (one cRCT, three PCSs): we found low-certainty evidence that food and nutrition subsidies may improve dietary diversity among school children. The evidence is very uncertain about the effects on household expenditure on healthy foods as a proportion of total expenditure on food (very low-certainty evidence). Interventions that addressed the social environment: Social support interventions (one cRCT, one PCS): we found moderate-certainty evidence that community grants probably make little or no difference to wasting; low-certainty evidence that they may make little or no difference to stunting. The evidence is very uncertain about the effects of village savings and loans on food security and dietary diversity. None of the included studies addressed the intervention category of infrastructure changes. In addition, none of the studies reported on one of the primary outcomes of this review, namely prevalence of undernourishment. AUTHORS' CONCLUSIONS: The body of evidence indicates that UCTs can improve food security. Income generation interventions do not seem to make a difference for food security, but the evidence is unclear for the other interventions. CCTs, UCTs, interventions that help generate income, interventions that help minimise impact of food prices through food vouchers and subsidies can potentially improve dietary diversity. UCTs and food vouchers may have a potential impact on reducing stunting, but CCTs, income generation interventions or social environment interventions do not seem to make a difference on wasting or stunting. CCTs seem to positively impact cognitive function and development, but not UCTs, which may be due to school attendance, healthcare visits and other conditionalities associated with CCTs.

An approach for setting evidence-based and stakeholder-informed research priorities in low- and middle-income countries.

To derive evidence-based and stakeholder-informed research priorities for implementation in African settings, the international research consortium Collaboration for Evidence-Based Healthcare and Public Health in Africa (CEBHA+) developed and applied a pragmatic approach. First, an online survey and face-to-face consultation between CEBHA+ partners and policy-makers generated priority research areas. Second, evidence maps for these priority research areas identified gaps and related priority research questions. Finally, study protocols were developed for inclusion within a grant proposal. Policy and practice representatives were involved throughout the process. Tuberculosis, diabetes, hypertension and road traffic injuries were selected as priority research areas. Evidence maps covered screening and models of care for diabetes and hypertension, population-level prevention of diabetes and hypertension and their risk factors, and prevention and management of road traffic injuries. Analysis of these maps yielded three priority research questions on hypertension and diabetes and one on road traffic injuries. The four resulting study protocols employ a broad range of primary and secondary research methods; a fifth promotes an integrated methodological approach across all research activities. The CEBHA+ approach, in particular evidence mapping, helped to formulate research questions and study protocols that would be owned by African partners, fill gaps in the evidence base, address policy and practice needs and be feasible given the existing research infrastructure and expertise. The consortium believes that the continuous involvement of decision-makers throughout the research process is an important means of ensuring that studies are relevant to the African context and that findings are rapidly implemented.

Afin de déterminer, à partir d'éléments factuels et avec l'apport des parties prenantes, les priorités de recherche pouvant être mises en œuvre dans les pays d'Afrique, le consortium de recherche international Collaboration for Evidence-Based Health Care and Public Health in Africa (CEBHA+) a élaboré et appliqué une démarche pragmatique. Tout d'abord, une enquête en ligne et une consultation en face à face entre les partenaires du CEBHA+ et les responsables politiques ont permis de mettre en lumière les domaines de recherche prioritaires. Ensuite, des listes documentaires relatives à ces domaines de recherche prioritaires ont permis d'identifier les lacunes ainsi que des questions connexes prioritaires en matière de recherche. Enfin, des protocoles d'étude ont été mis au point en vue d'être intégrés à une proposition de subvention. Des représentants de la mise en œuvre des politiques ont participé à l'ensemble du processus. La tuberculose, le diabète, l'hypertension et les blessures de la route ont été sélectionnés comme domaines de recherche prioritaires. Les listes documentaires portaient sur le dépistage et les modèles de soins du diabète et de l'hypertension, sur la prévention de ces maladies ainsi que sur leurs facteurs de risque au niveau de la population, et sur la prévention et la prise en charge des blessures de la route. L'analyse de ces listes a permis de dégager trois questions de recherche prioritaires portant sur l'hypertension et le diabète et une sur les blessures de la route. Les quatre protocoles d'étude en découlant utilisent toute une série de méthodes de recherche primaire et secondaire; un cinquième favorise une démarche méthodologique intégrée sur l'ensemble des activités de recherche. La démarche du CEBHA+, en particulier la constitution de listes documentaires, a permis de formuler les questions de recherche et les protocoles d'étude qui reviendront aux partenaires africains, de combler les lacunes des bases de données et de répondre aux besoins en matière de politiques et de pratiques; elle s'est également révélée applicable compte tenu de l'expertise et de l'infrastructure de recherche existantes. Pour le consortium, l'implication continue des décisionnaires dans le processus de recherche est un important moyen de garantir que les études soient pertinentes pour les pays africains et que leurs résultats soient rapidement mis en œuvre.

Para obtener las prioridades de investigación documentadas y comunicadas a las partes interesadas para su implementación en África, el consorcio de investigación internacional Asociación de Asistencia Médica Basada en Evidencia en África (CEBHA+, por sus siglas en inglés), desarrolló y aplicó un enfoque pragmático. En primer lugar, una encuesta en línea y una consulta presencial entre socios de la CEBHA+ y responsables políticos originó los sectores de investigación prioritarios. En segundo lugar, unos mapas documentados para estos sectores de investigación prioritarios identificaron disparidades y asuntos relativos a la investigación prioritaria. Por último, se desarrollaron protocolos de estudio para incluirlos dentro de una propuesta de subvención. Los representantes políticos y prácticos participaron durante todo el proceso. Los sectores de investigación prioritarios seleccionados fueron la tuberculosis, la diabetes, la hipertensión y los traumatismos provocados por accidentes de tráfico. Los mapas documentados abordaron el examen y los modelos de asistencia de la diabetes y la hipertensión, la prevención de la diabetes y la hipertensión a nivel de población, sus factores de riesgo y la prevención y gestión de traumatismos provocados por accidentes de tráfico. Los análisis de estos mapas generaron tres asuntos de investigación de prioridades sobre hipertensión y diabetes y uno sobre traumatismos provocados por accidentes de tráfico. Los cuatro protocolos de estudio resultantes emplean una amplia gama de métodos de investigación primarios y secundarios; un quinto presenta un enfoque metodológico integrado a través de todas las actividades de investigación. El enfoque de la CEBHA+, concretamente los mapas documentados, contribuyó a formular cuestiones y protocolos de estudio sobre la investigación que pertenecerían a socios africanos, subsanarían diferencias en la base de pruebas, abordarían las necesidades sobre políticas y prácticas y serían viables gracias a la infraestructura y experiencia de investigación existentes. El consorcio considera que la constante implicación de los responsables de la toma de decisiones a lo largo del proceso de investigación es un medio importante para garantizar que los estudios se correspondan al contexto africano y que los resultados se implementen con rapidez.

Evidence insufficient to confirm the value of population screening for diabetes and hypertension in low- and-middle-income settings.

To assess the evidence from systematic reviews on the effect on morbidity and mortality of blanket screening for hypertension or diabetes mellitus compared with targeted, opportunistic or no screening, we searched for relevant systematic reviews and conducted duplicate study selection, data extraction and quality appraisal. Results were summarised narratively. We included two completed reviews of moderate quality and one ongoing Cochrane review. In one completed review, general health checks had no effect on total morbidity or mortality or on healthcare services compared with no health checks. In the other, intensive hypertension screening methods were ineffective in increasing screening uptake or detecting new cases compared with less intensive methods. Both reviews included studies in high-income settings. There is insufficient evidence from currently available systematic reviews to confirm a beneficial effect of blanket screening for hypertension and/or diabetes compared with other types of screening methods in low- and middle-income settings. Scarce resources are being mobilised to implement mass screening intervention for diabetes and hypertension without adequate evidence of its effects. A systematic review is needed to assess clinical effectiveness, cost-effectiveness and overall impact on the health system of screening strategies, especially in low- and middle-income settings such as exist in South Africa. Robust evaluation of these outcomes would then be necessary to inform secondary prevention strategies.

Validation of a search strategy to identify nutrition trials in PubMed using the relative recall method.

OBJECTIVES: To develop, assess, and maximize the sensitivity of a search strategy to identify diet and nutrition trials in PubMed using relative recall. STUDY DESIGN AND SETTING: We developed a search strategy to identify diet and nutrition trials in PubMed. We then constructed a gold standard reference set to validate the identified trials using the relative recall method. Relative recall was calculated by dividing the number of references from the gold standard our search strategy identified by the total number of references in the gold standard. RESULTS: Our gold standard comprised 298 trials, derived from 16 included systematic reviews. The initial search strategy identified 242 of 298 references, with a relative recall of 81.2% [95% confidence interval (CI): 76.3%, 85.5%]. We analyzed titles and abstracts of the 56 missed references for possible additional terms. We then modified the search strategy accordingly. The relative recall of the final search strategy was 88.6% (95% CI: 84.4%, 91.9%). CONCLUSION: We developed a search strategy to identify diet and nutrition trials in PubMed with a high relative recall (sensitivity). This could be useful for establishing a nutrition trials register to support the conduct of future research, including systematic reviews.