Slum upgrading strategies involving physical environment and infrastructure interventions and their effects on health and socio-economic outcomes
Slums are densely populated and neglected parts of cities where housing and living conditions are exceptionally poor. Slums lack basic services, particularly access to potable water and sanitation, and often have many people crowded into small living spaces. However, slums can provide shelter and proximity to jobs, and communities are often close-knit, social and supportive. Some one billion people worldwide live in areas designated as slums; more than 90% of these are located in low- and middle-income countries (LMIC). With demographic projections estimating that 60% of the world’s population will be urban dwellers by the 2030s, living conditions in slums and associated public health considerations are likely to be of increasing concern for governments worldwide.
Slum upgrading, in its most basic form, involves improvements in the physical environment of the existing area. Examples of what this might involve include improving or installing basic infrastructure services such as water, sanitation, solid waste collection, electricity, storm water drainage, access roads, footpaths and street lighting. Interventions may also include home improvements and securing land tenure and also interventions related to services (such as health and education) and livelihoods. The purpose of most slum upgrading strategies is to improve the health and quality of life for residents of slums, and a team of Cochrane authors, working with the Cochrane Public Health Review Group, set out to explore the effects of slum upgrading strategies involving physical environment and infrastructure interventions on the health, quality of life and socio-economic wellbeing of urban slum dwellers in low- and middle-income countries (LMIC).
After reviewing nearly 10,500 records of different papers, commentaries and other documents that were published up to April 2012, the Cochrane Review team identified five studies that had evaluated slum upgrading strategies on the outcomes described above. In all these studies, the impact of interventions was assessed by comparing the outcomes with similar areas where no interventions had been undertaken. Three of these studies focused on multicomponent upgrading programs; one on road paving only; and one on water supply. Most of the health outcomes measured in these studies focused on communicable diseases. The authors identified an additional nine studies for use in supporting analyses; however, the majority of these had a high risk of bias, meaning that their methods had several limitations that made the study results less reliable. The authors determined, on the basis of available studies, that there was consistent evidence to suggest that slum upgrading may reduce diarrhoea in slum dwellers and their water-related expenses. Evidence for other outcomes, including infections, poverty, and unemployment, was mixed or lacking, and the author team provides recommendations for future research, noting that “The potential for studies to reduce bias is greatest when evaluations are planned at the same time as the design and delivery of the intervention and independent researchers are involved in intervention allocation and data collection.”
The Cochrane Review team is a multinational group, with authors based in Asia, Europe, and the US. One of the authors, Ruhi Saith, is based in New Delhi, and is co-leading the new satellite of the Cochrane Public Health Review Group. Based in India, the satellite will form part of the new Public Health Evidence South Asia initiative, which is working with public health and development agencies across the South Asia region. The satellite aims to build capacity to address LMIC health priorities through investments in the region, focusing on producing systematic reviews relevant to South Asia; translating evidence into policy through working with government agencies, NGOs, and community networks; building capacity and leaders of the future, and integrating collection of evidence into future initiatives to expand the evidence base.
Dr Ruhi Saith says “The slum upgrading review is an excellent example of planned activities for the satellite. Funded by 3ie, the review brought together both experienced and novice authors from a LMIC, helping to build capacity and ensure that the review met the needs of low and middle income countries. We hope that the satellite will continue to contribute by highlighting ways to improve evaluations, promote the publication and use of systematic reviews on topics of public health relevance in LMICs and use the evidence from these reviews to influence policy.”