Complex Public Health Interventions Research Articles

Evidence synthesis, upstream determinants and health inequalities: the role of a proposed new Cochrane Public Health Review Group

Within public health decision making, there has been an increasing awareness of the need for better syntheses of evidence related to interventions addressing upstream, population-level determinants of health and health inequalities. This includes focusing greater attention on ways of integrating evidence from a range of sources and on best ways of using what evidence is currently available, while remaining aware of its limitations. 1 Inherent within this is the need to consider further the contribution and value of multiple forms of evidence to the evidence base rather than a stringent focus on ranking evidence by more traditional scientific measures. Whilst we would argue that well-conducted experimental studies provide strong evidence on intervention effectiveness it is not always possible to carry out such studies when evaluating complex public health interventions. Accordingly, exploring ways of incorporating diverse evidence sources into systematic reviews, together with a realistic view of the scope, strengths and limitations of such evidence, needs consideration if public health is to make an effective contribution to impacting health inequalities and the social determinants of health. High quality systematic reviews can inform both the development of further primary research as well as policymaking, which does not absolve the need for better primary research on the effectiveness and economic efficiency of interventions and policies with regards to health inequalities, 2 but primary research must be informed by better understanding of what research already exists and hence where the gaps are.

Evaluating complex public health interventions: theory, methods and scope of realist enquiry

The standard models used in the study of complex public health interventions are inadequate. They adopt a simple empiricist theoretical foundation and attempt to graft onto an essentially open social system a contrived laboratory experimentation typically in the form of a randomized, controlled trial. By understanding the ontological and epistemological claims of critical realism, it is possible to transcend the methodological inadequacy of the standard model approach. Critical realism posits a substantive causal theory, an end to fact-value dualism, and a coherent and emancipatory model of social action; all of these features amount to a systematic and compelling account of public health practice and a coherent approach to evaluation of complex public health interventions.

Community development as health promotion: evaluating a complex locality-based project in New Zealand

This article examines the evaluation of a complex public health intervention - the Ranui Action Project (RAP). The RAP utilized a community development approach to address the social determinants of health inequalities in a high need, ethnically diverse, urban locality. The rationale and impetus for the project was emerging evidence in the public health literature on the significance of working intersectorally with an emphasis on social capital and social cohesion as neighbourhood-level determinants of health. This article describes RAP and examines the strengths, limitations and challenges of the formative, process and impact evaluation model used to evaluate the programme's effectiveness. Responding to diverse evaluative expectations, while sustaining research integrity and rigour, requires a pragmatic multi-methods approach, responsiveness to local context, regular communication between funders, community stakeholders and evaluators, and flexible, reflective practice.

Evaluating the effect of policies and interventions to address inequalities in health: lessons from a Dutch programme

Many initiatives have been taken in European countries that are designed to reduce inequalities in health. However, the effects of only a very few of these initiatives have been assessed. The main aim of a Dutch research and development programme was to systematically investigate and evaluate interventions aimed at reducing inequalities in health. In this paper, we report on this investigation, and draw lessons from the methodology used to evaluate such interventions. The programme included 12 evaluation studies, focusing on the wider determinants of inequalities in health (n = 2), behavioural determinants (n = 4), working conditions (n = 3) and health care (n = 3). An experimental design was applied in two evaluation studies. The studies provided evidence of a positive effect. A quasi-experimental design appeared to be the only attainable option in seven studies. Five of these provided sufficient evidence for a positive effect, but two interventions appeared not to be successful. In three studies, no experimental or quasi-experimental design could be applied. The programme showed that it is possible to apply experimental or quasi-experimental studies to complex public health interventions. The Programme Committee steering the programme considered that the evidence generated by the experimental and quasi-experimental studies justified the implementation of the interventions on a wider scale, accompanied by further evaluation studies. Further development of the methodology of public health interventions is necessary. These include non-experimental designs such as international comparisons and time trend studies, especially in order to be able to evaluate broader policy measures.

Rationale, design and conduct of a comprehensive evaluation of a school-based peer-led anti-smoking intervention in the UK: the ASSIST cluster randomised trial [ISRCTN55572965

BackgroundTo date, no school-based intervention has been proven to be effective in preventing adolescent smoking, despite continuing concern about smoking levels amongst young people in the United Kingdom. Although formal teacher-led smoking prevention interventions are considered unlikely to be effective, peer-led approaches to reducing smoking have been proposed as potentially valuable.Methods/designASSIST (A Stop Smoking in Schools Trial) is a comprehensive, large-scale evaluation to rigorously test whether peer supporters in Year 8 (age 11–12) can be recruited and trained to effect a reduction in smoking uptake among their fellow students. The evaluation is employing a cluster randomised controlled trial (RCT) design with secondary school as the unit of randomisation, and is being undertaken in 59 schools in South East Wales and the West of England. Embedded within the trial are an economic evaluation of the intervention costs, a process evaluation to provide detailed information on how the intervention was delivered and received, and an analysis of social networks to consider whether such a peer group intervention could work amongst schoolchildren in this age group.Schools were randomised to either continue with normal smoking education (n = 29 schools, 5562 students), or to do so and additionally receive the ASSIST intervention (n = 30 schools, 5481 students). No schools withdrew once the trial had started, and the intervention was successfully implemented in all 30 schools, with excellent participation rates from the peer supporters. The primary outcome is regular (weekly) smoking, validated by salivary cotinine, and this outcome has been obtained for 94.4%, 91.0% and 95.6% of eligible students at baseline, immediate post-intervention, and one-year follow-up respectively.DiscussionComprehensive evaluations of complex public health interventions of this scale and nature are rare in the United Kingdom. This paper demonstrates the feasibility of conducting cluster RCTs of complex public health interventions in schools, and how the rigour of such designs can be maximised both by thorough implementation of the protocol and by broadening the scope of questions addressed in the trial by including additional evaluative components.