Author
CANDY Bridget; et al;
The health impact of policy interventions tackling the social determinants of common mental disorder: a systematic review.
Journal citation/publication details
Journal of Public Mental Health, 6(2), June 2007, pp.28-39.
Summary
This review identifies little robust evidence on the mental health impacts of a range of social policy interventions except in the area of housing and urban regeneration, although on-going evaluations of major programmes such as the New Deal for the Communities and Sure Start hold promise. This review may have been conducted ‘too soon’, and a meaningful examination of the evidence may need to await developments in both evaluation and review methodology that can take account of the complexities of social interventions and their impacts.
Context
The most socially and economically disadvantaged members of society are at greater risk of a range of poorer health outcomes, including common mental disorder (CMD) which encompasses anxiety disorders and mild to moderate affective disorders. This review explores evidence on the impact of UK social policy interventions, especially in England and Wales, that are intended to address identified determinants of CMD.
Methods
What sources were used?
The Social Science Citation Index and IBSS (International Bibliography of the Social Sciences) were searched, and contact was made with unnamed ‘subject experts’. In addition, the results of searches carried out in Medline, PsycINFO, EMBASE (Excerpta Medica), Geobase and ICONDA (International Construction Database) for overlapping reviews conducted by the team were also checked. It appears that the reference lists of relevant studies were also checked and/or citation checking was carried out, although this is not entirely clear.
What search terms/strategies were used?
Preliminary identification of key UK and Welsh Assembly national policy documents revealed key policy initiatives to inform the searches, i.e. Communities First; New Deal work programmes; New Deal for Communities; the Sustainable Health Action Research Programme; Sure Start local programmes; tax credits; and the minimum wage. The specific search strategy used with the two databases is reproduced as Table 1 but does not include all these programmes as search terms.
What criteria were used to decide on which studies to include?
Eligible studies were published in peer reviewed journals and focused on the health impact of interventions to reduce unemployment levels and social isolation, raise low income, assist family functioning, improve housing or neighbourhood conditions, or remedy negative psychosocial factors associated with the workplace. Interventions to promote healthy lifestyles were excluded. The date range was limited to January 1997 (close to when the Labour government, with an explicit focus on policies to reduce health inequalities, took office) to December 2005. Given the very wide nature of the inclusion criteria, the search strategy in Table 1 appears rather limited.
Who decided on their relevance and quality?
The searches produced 733 references, which were independently checked by two unnamed reviewers for eligibility. Ten potentially relevant studies were identified, but on reading in full all but three were eliminated because they discussed the process of evaluation rather than reporting the effects of an intervention. Selected studies, all quantitative, were quality assessed on the basis of the approach recommended by the Oxford Centre for Evidence-Based Medicine.
How many studies were included and where were they from?
The three studies from the searches were supplemented by 11 more from the searches for the two overlapping reviews, and from expert consultation. The 14 studies included two systematic reviews, and those relating to housing and urban regeneration are summarised in Table 2. This sub-set of studies were from the UK (5), USA (2) and Norway (1).
How were the study findings combined?
The synthesis is narrative, by theme.
Findings of the review
All but one of the individual trials were graded as low quality because of lack of randomisation. One systematic review was also graded as low quality, and the other was not graded because it identified no evidence of suitable quality to review.
Housing and neighbourhood regeneration
Much of the evidence for mental health impact related to housing and neighbourhood regeneration, including one of the systematic reviews and seven evaluations not identified for that review. With the exception of two housing refurbishment studies, all showed an association with improved mental health. but these findings ‘need to be treated with caution’ because of numerous methodological inadequacies, e.g. small sample sizes, cross-sectional or retrospective design, and lack of control for key confounding variables. On-going large scale and better designed evaluations of the New Deal for Communities should provide more robust evidence, and preliminary findings suggest an improvement in self-reported health, but marked variation by population group and region.
Employment interventions
No eligible evidence on the mental health effects of UK employment programmes was found. Two randomised controlled trials (RCTs) from the USA and Finland are described as relevant to the UK context and found that, after controlling for confounding variables, that those engaging in programmes designed to improve their job searching skills had improved employment outcomes and significantly lower levels of depression two years later. The reviewers also note the potential relevance of the on-going evaluation of the New Deal for Communities, and a systematic review in progress at the MRC Social and Public Health Sciences Unit at Glasgow University.
Income supplementation
A 1999 systematic review examining RCTs of the impact of income supplementation on physical and mental health is based primarily on US evidence published before the mis-1980s. It found no reliable evidence on any health outcomes.
Parenting and childhood deprivation
No completed evaluations were identified of interventions designed to reduce the identified social determinants of poor mental health outcomes from poverty, parental break-up and/or lack of social support. Evidence from on-going evaluations of Sure Start local programmes (SSLP) is mixed, with only small differences in the health and development of children between SSLP and non-SSLP areas.
Psychosocial work characteristics, and social inclusion
No evaluations were found of the mental health impact of interventions relating to psychosocial work characteristics. The MRC Social and Public Health Sciences Unit at Glasgow University is currently undertaking a review in this area. Similarly, no evidence was identified on policy interventions relating to the social support, social relations and social isolation dimensions of social exclusion and mental health.
Authors' conclusions
The authors note the lack of evidence in many areas of interest, and look forward to the results of the more robust evaluation studies of various UK programmes now underway, and well as other systematic reviews in progress. They accept that their searching – in particular the sources used – may have been too limited, but also suggest that the lack of evidence may be a product of the difficulties in measuring the actual or potential health impact of non-health policies, especially mental health outcomes which are less tangible than those for physical health. The ethical problems of conducting RCTs of social policy interventions may be a further explanation and, finally, the authors believe they may simply have conducted their review ‘too soon’. In order to move forward, there will need to be developments in both evaluation and review methodology, and a consensus on what should count as evidence in these complex policy areas.
Implications for policy or practice
None are discussed.