This guest blog was written by Dr Ruhi Saith, a Research Fellow based in New Delhi and an author of the review from the Cochrane Public Health Group on which this blog is based.
Globally over one billion slum dwellers reside in informal housing and according to UN predications this figure will increase to 1.4 billion by 2020. Whilst progress towards the UN millennium goals, which aim to improve the lives of slum dwellers, is being made, slum improvements have failed to keep pace with the growing ranks of the urban poor.
To overcome the poor standards of living which can be rife within slum areas, the past 15 years has seen consistent political commitment to large-scale slum upgrading programmes. Strategies have sought to improve, formalise and incorporate informal urban areas into cities and also improve the health and livelihoods of people living and working in these areas.
Understanding what works
So, while valuable resources continue to be invested in slum upgrading strategies, how can these resources be invested in the most effective and efficient way? How can policy makers and implementers know what interventions will work to improve the health and wellbeing of those living in slum areas?
Until recently, the evidence on the effectiveness of strategies to reduce the ill effects of urban slums had not been examined systematically. Our review was the first comprehensive review of slum upgrading programmes, collating all relevant research and providing a broad picture of the effectiveness of strategies across different settings, interventions and outcomes. At the same time the review considered the reliability and validity of results and measures within each study.
There are many types of slum upgrading programmes, all which have the potential to effect various and interwoven health and socio-economic outcomes. Our review looked specifically at interventions involving physical environments and infrastructure changes. For instance, we looked at interventions that might improve water and sanitation, energy infrastructure, electricity, transport infrastructure, mitigation of environmental hazards, waste management or housing improvements. But we also wanted to know if these interventions had been combined with other interventions to improve health, education or social services.
We then wanted to understand how these strategies might impact on health and quality of life of slum dwellers in these areas. Such changes to health were determined by changes to mortality and morbidity and where associated to levels of communicable and non-communicable diseases and quality of life measures. In addition, the review examined whether upgrades could affect socio-economic status. We asked whether upgrades could result in changes to financial poverty, employment and occupation or crime and violence, education or social capital.
Here’s what we found:
Following a comprehensive search of the literature, we found that five main studies had used suitable methods for examining the effect of slum upgrading on health, quality of life and social wellbeing. We also identified a further nine supporting studies which could indicate associations between interventions and outcomes. However, due to the methods used in these supporting studies, we could not assess whether the interventions in these studies actually caused the reported effect.
After we had looked at the reliability and validity of the results and measures in all of the studies, we found
- Limited but consistent evidence to suggest that slum upgrading may reduce diarrhoea in slum dwellers and that slum dweller’s water related expenses may also be reduced
- Mixed results for whether slum upgrading can reduce parasitic infections, educational outcomes, financial poverty and unemployment outcomes
- Very little information on other health or social outcomes, or which types of interventions were most beneficial
- Some of the studies we included in the review, asked slum dwellers for their views and their experiences of slum upgrading interventions and these studies suggested a number of reasons why facilities were not used as intended and the factors which may have reduced the benefits of the upgrade
So, what does this review actually tell us? Whilst our review demonstrates that slum upgrading strategies can improve aspects of health and economic social wellbeing, the review also demonstrates that there are a number of evidence gaps around their effectiveness. We still do not understand what effects physical slum upgrades can have on other aspects of health and wellbeing. Research is needed to examine the effects of slum upgrades on non-communicable diseases, quality of life, employment, education, social capital, injuries and crime.
To close these evidence gaps further, research is required using more rigorous methods. Until evaluation study designs are improved, we will not be able to draw firm conclusions on the impact of slum upgrading strategies.
In the future it is vital that those involved in slum upgrades undertake independent and high quality evaluations of upgrade interventions, including a comparison of different interventions and approaches of implementation. If we are to continue to progress towards the Millennium Development goals, these evaluations will be essential to help determine how valuable resources can be invested to improve the conditions of existing slums and to offer the most benefit to the health, quality of life and social wellbeing of slum dwellers.
Turley R, Saith R, Bhan N, Rehfuess E, Carter B. Slum upgrading strategies involving physical environment and infrastructure interventions and their effects on health and socio-economic outcomes. Cochrane Database of Systematic Reviews 2013, Issue 1. Art. No.: CD010067. DOI: 10.1002/14651858.CD010067.pub2.
Click here to read a feature on this review on the Cochrane Collaboration website.
Click here to listen to a podcast about the review.