Thea de Wet

Identifying important life stages for monitoring and assessing risks from exposures to environmental contaminants: results of a World Health Organization review.

Highlights • We propose a harmonized set of age bins for assessing risks from chemical exposure.• The set of early life age groups will facilitate consistency with recent guidance.• The age bins allow results from longitudinal birth cohort studies to be combined.• Region-specific exposure factors and monitoring data are needed to apply the bins.

Purity or pragmatism? Reflecting on the use of systematic review methodology in development

Systematic review methodology pioneered in health care has been increasingly applied to development questions of importance in lower- and middle-income countries. This paper reports one such review on the topic of microfinance in sub-Saharan Africa and reflects on the number of pragmatic methodological compromises made when applying the method to a new field. These compromises relate to multidisciplinary teamwork, application of regional filters, drawing on evidence from additional study types and exploring mechanisms for change through the development and testing of a causal pathway. The paper concludes that a pragmatic rigorous approach to systematically reviewing evidence of effectiveness is needed for international development.

Poor housing, good health: a comparison of formal and informal housing in Johannesburg, South Africa

ObjectivesThis study aimed to investigate the relationship between housing, demographic, socio-economic, social factors and health, in poor urban communities in Johannesburg, South Africa.MethodsData were drawn from a survey of 1,427 households in Johannesburg. The outcome health variable was a composite measure of chronic ill-health. Housing variables included type of housing, tenure and access to services. Multivariate regression analysis assessed the relationship between housing and health, after adjustment for demographic, socio-economic and social factors.ResultsThe prevalence of chronic health problems was 25.1% (95% CI 22.8–27.6%). Factors independently associated with the risk of chronic ill-health among household heads included older age (OR, 3.06 [2.37–3.95]), female gender (OR, 2.83 [2.01–3.97]), long-term residence (OR, 2.01 [1.10–3.67]), unemployment (OR, 0.49 [0.36–0.67]), and living in formal housing (OR, 0.66 [0.45–0.98]).ConclusionsThe health of the household heads residing in informal housing was significantly better than in formal housing. Explanations for this counter-intuitive finding include the fact that the informal housing dwellers were younger and recent migrants (the ‘healthy migrant’ phenomenon). Policy implications of the results are identified.

The size and nature of the evidence-base for smallholder farming in Africa: a systematic map

Relevant systematic reviews and impact evaluations were systematically sought and described in order to assess the size and nature of the evidence-base about the effectiveness of interventions for smallholder farmers in Africa. A total of 21 relevant systematic reviews and 415 reports of impact evaluations were identified. This paper describes this African evidence-base in terms of the interventions and outcomes assessed, and the geographical spread of the primary research across the continent. Gaps in the evidence-base are identified and recommendations made for future research.

Inequity in poverty: the emerging public health challenge in Johannesburg

In 2005, in recognition of the role of social factors in increasing health inequities, the World Health Organisation established the Commission on the Social Determinants of Health. South Africa is among the most unequal societies in the world. It faces serious public health challenges, including an elevated burden of chronic disease, and high levels of violence. This paper presents data from a cross-sectional study of socio-economic and health status conducted in five Johannesburg housing settlements in 2006. The findings paint a picture of health inequities across and within the study sites, and socio-environmental conditions that undermine the prospects of protecting and promoting health. The authors suggest the need for a new approach to public health in areas of urban impoverishment in Johannesburg and elsewhere.

What are the impacts of urban agriculture programs on food security in low and middle-income countries: a systematic review

BackgroundUrban Agriculture is considered to contribute to improved food security among the income poor in urban contexts across developing countries. Much literature exists on the topic assuming a positive relationship. The aim of this review was to collect and analyse available evidence on the impact of urban agriculture in low and middle-income countries.MethodsWe employed systematic review methods to identify all relevant and reliable research on UA’s impact on food security and nutrition. Only impact evaluations that set out to measure the effectiveness of UA interventions on food security, as compared to the effects of not engaging in UA, qualified for inclusion. Studies had to have a comparison group and at least two data points.ResultsSystematic searches resulted in 8142 hits, and screening of abstracts resulted in 198 full texts identified. No studies met the review’s inclusion criteria. Therefore, the review found no available evidence that supports or refutes the suggestion that urban agriculture positively impacts on individual or household food security in low and middle-income countries. The largest proportion of studies at full text stage was excluded based on study design, as they were not impact evaluations, i.e. they did not have a comparison group and at least data points. Two observations were made: Firstly, searches yielded a range of studies that consider associations between UA and certain aspects of food security. Secondly, there is a large pool of cross-sectional studies on UA’s potential to contribute to increased food security, particularly from west and east Africa.ConclusionsThe research currently available does not allow for any conclusions to be made on whether or not urban agriculture initiatives contribute to food security. The fact that impact evaluations are absent from the current evidence-base calls for increased efforts to measure the impact of urban agriculture on food security in low and middle-income countries through rigorous impact evaluations. With regard to systematic review methodology, this review alludes to the value of compiling a systematic map prior to engaging in a full systematic review.

Walking the last mile on the long road to evidence-informed development: building capacity to use research evidence

The systematic application of rigorous evidence to inform the design and implementation of development policies and programmes has the potential to positively influence development outcomes. To achieve such evidence-informed development, a process of generating, transmitting, and using high-quality, policy-relevant evidence of development effectiveness is required. This article focuses on the final step in this casual chain – the use of evidence by national development policymakers. It proposes a people- and demand-focused approach to capacity building for the use of research evidence by policymakers. This support in building personal as well as team capacity and demand is assumed to encourage a growing institutionalisation of evidence use. The article integrates these capacity-building efforts into the wider theory of change for evidence-informed development, highlighting the importance of effective mechanisms to encourage research use in order to achieve the objective of improving lives through research evidence.

Big city, big data

This forum addresses conceptual, methodological, and professional issues that arise in the UX fields continuing effort to contribute robust information about users to product planning and design. --- David Siegel and Susan Dray, Editors

What is the evidence on smallholder agriculture interventions in Africa

A majority of people living in poverty in rural Africa are smallholder farmers. Though the Green Revolution has improved livelihoods in Asia and Latin America, innovative farming practices have not been implemented as widely in Africa. Supporting smallholder agriculture through training, innovation and new technology has the potential to improve households’ incomes and food security, and boost rural economies.