摘要：Objectives. We conducted a systematic review of the health impacts of housing improvement. Methods. Forty-two bibliographic databases were searched for housing intervention studies from 1887 to 2007. Studies were appraised independently by H. T. and S. T. or E. S. for sources of bias. The data were tabulated and synthesized narratively, taking into account study quality. Results. Forty-five relevant studies were identified. Improvements in general, respiratory, and mental health were reported following warmth improvement measures, but these health improvements varied across studies. Varied health impacts were reported following housing-led neighborhood renewal. Studies from the developing world suggest that provision of basic housing amenities may lead to reduced illness. There were few reports of adverse health impacts following housing improvement. Some studies reported that the housing improvement was associated with positive impacts on socioeconomic determinants of health. Conclusions. Housing improvements, especially warmth improvements, can generate health improvements; there is little evidence of detrimental health impacts. The potential for health benefits may depend on baseline housing conditions and careful targeting of the intervention. Investigation of socioeconomic impacts associated with housing improvement is needed to investigate the potential for longer-term health impacts. Investment in improving poor housing conditions has long been proposed as a mechanism for health improvement and the reduction of health inequalities. For example, the World Health Organization (WHO) Knowledge Network on Urban Settings and the WHO Commission on the Social Determinants of Health have highlighted the need to create healthy housing and neighborhoods. 1 The US Centers for Disease Control and Prevention also stresses the improvement of housing and living conditions as a strategy to promote health. 2 Within the field of public health more generally, housing policy is also regularly cited as a determinant of both health and health inequalities 3 , 4 and as a means by which inequalities may be tackled. 5 , 6 Public investment to improve housing conditions can be justified on grounds of social justice and energy efficiency. In addition, the well-established associations between poor housing and poor health also suggest that housing improvement may be justified on health grounds alone. There is a complex interconnectedness between poor housing and poor health and their determinants. 3 For example, vulnerable groups such as the sick, the elderly, and the unemployed are among those most likely to live in poor housing and also tend to spend long periods of time indoors exposed to potentially hazardous environments. 7 Thus, the improvement of housing conditions may be used to tackle the complex dynamic between poverty and poor health. None of these impacts can be taken for granted, however, and evidence about the actual impacts of housing improvement needs to be rigorously synthesized to ensure that policies meant to improve health through housing have a sound scientific footing. In a previous systematic review examining the health impacts of housing improvements, we found 18 studies from around the world. 8 We concluded that housing improvements may have produced small improvements in health, particularly mental health. However, the small number, extreme heterogeneity, and poor quality of the studies inevitably limited the ability to draw conclusions in the final synthesis. Our previous review identified 12 ongoing studies of housing improvement that would be complete by 2006, some of which used quasi-experimental designs; it is now timely to prepare an updated synthesis drawing on these recent studies. We report the findings of a systematic review of the health impacts of housing improvement. The review is distinct from our earlier one; a new and more comprehensive search strategy was developed, a more detailed critical appraisal of the included studies was carried out, and the final synthesis incorporated the use of standardized effect sizes and a narrative synthesis of both quantitative and qualitative data. In addition, the increased quantity and quality of recent studies allowed for synthesis of larger groups of similar studies, increasing the generalizability of the final synthesis.
