Policy directions in urban health in developing countries--the slum improvement approach.

The urban development, or housing, sector has a longer experience of addressing the problems of the urban poor in developing countries than the health sector. In recent years the policy of 'slum improvement', which involves both sectors, has attracted the support of international donors. This article documents the development of the slum improvement approach and addresses key issues of the approach which have implications for health planning: covering the poorest dwellers; relocation; land tenure; gentrification; debt burdens and the impact on women. Questions about the approach which still need answering are defined and a summary of the constraints in slum improvement and potential solutions is presented.