Slum upgrading strategies involving physical environment and infrastructure interventions and their effects on health and socio‐economic outcomes

Background Slums are densely populated, neglected parts of cities where housing and living conditions are exceptionally poor. In situ slum upgrading, at its basic level, involves improving the physical environment of the existing area, such as improving and installing basic infrastructure like water, sanitation, solid waste collection, electricity, storm water drainage, access roads and footpaths, and street lighting, as well as home improvements and securing land tenure. Objectives 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). Where reported, data were collected on the perspectives of slum dwellers regarding their needs, preferences for and satisfaction with interventions received. Search methods We searched for published and unpublished studies in 28 bibliographic databases including multidisciplinary (for example Scopus) and specialist databases covering health, social science, urban planning, environment and LMIC topics. Snowballing techniques included searching websites, journal handsearching, contacting authors and reference list checking. Searches were not restricted by language or publication date. Selection criteria We included studies examining the impact of slum upgrading strategies involving physical environment or infrastructure improvements (with or without additional co‐interventions) on the health, quality of life and socio‐economic wellbeing of LMIC urban slum dwellers. Randomised controlled trials (RCTs), controlled before and after studies (CBAs) and interrupted time series (ITS) were eligible for the main analysis. Controlled studies with only post‐intervention data (CPI) and uncontrolled before and after (UBA) studies were included in a separate narrative to examine consistency of results and to supplement evidence gaps in the main analysis. Data collection and analysis Two authors independently extracted data and assessed risk of bias for each study. Differences between the included study interventions and outcomes precluded meta‐analysis so the results were presented in a narrative summary with illustrative harvest plots. The body of evidence for outcomes within the main analysis was assessed according to GRADE as very low, low, moderate or high quality. Main results We identified 10,488 unique records, with 323 screened as full text. Five s