December 12th, 2017
Background: Epidemiological surveys have shown strong associations between housing and health but have been unable to show causal links. Intervention studies are, however, necessary to establish and explain causal links between housing and health. Evidence from such studies can be used to inform specific housing investment and predict health its health gains. Aims: To provide policy makers and researchers with a summary of the evidence regarding the health impacts of housing interventions derived from experimental and non-experimental studies of housing interventions. To make methodological recommendations for future research needs in the area. Objective: To systematically review the evidence for the effectiveness of housing improvement as a health improvement measure. Methods:A systematic review of experimental and non-experimental housing intervention studies which measured quantitative health outcomes. Studies dating from 1887, in any language or format, were identified from 17 clinical, social science and grey literature databases, personal collections, expert consultation and reference lists. Interventions to improve the indoor environment by means of furniture or indoor equipment were excluded unless they were part of other housing improvements. Results: Nineteen completed studies dating from 1936 were identified. Interventions included Medical Priority Rehousing, energy efficiency improvements, rehousing, community regeneration and refurbishment. Eleven of the studies were prospective, of which six had control groups. Three of the retrospective studies used a control group. One study had used qualitative methods. The range of interventions covered, together with the range of outcomes used and problems with study methodologies make it difficult to produce a clear statement of the effect of housing improvements.A summary of the most methodologically sound studies, however, suggests that investment in housing does have the capacity to improve health; eight of nine studies which measured mental health showed improvements and one study demonstrated a ‘dose-response’ effect. Effects on specific physical outcomes (ie general health, respiratory symptoms) were less clear with similar studies sometimes showing similar sized effects but in opposite directions.Adverse effects of housing improvements were also reported in a number of studies of rehousing and regeneration. In one study mortality rates increased. This was attributed to a doubling in rents which effected the households' ability to afford an adequate diet. The identification of 14 ongoing housing intervention studies suggests increasing interest in generating evidence on how housing might improve health. Many of these studies are multi-disciplinary and indicate an increasing acceptance of collaborative, mixed method quasi-experimental evaluation of social interventions.