Using a theory driven mixed-method review to assess the benefits of complex environmental-health programmes. Cochrane Public Health Group review CD010351

Article type
Authors
Lovell R1, Husk K1, Cooper C2, Garside R1
1ECEHH University of Exeter Medical School, UK
2PenTAG University of Exeter Medical School, UK
Abstract
Background: This presentation will describe our use of a novel approach to synthesising disparate bodies of quantitative and qualitative evidence to understand both the benefits and pathways to impact of outdoor environmental enhancement and conservation activities to health and wellbeing.

Objectives: Environmental enhancement programmes are complex and heterogeneous, particularly in setting, intervention specifics, participant population and motivation, and evaluatory technique. We therefore sought to use an innovative model of synthesis suitable to assess the potential impacts of activities to health and wellbeing, whilst developing an understanding of how, why and where these impacts may occur.

Methods: For this Cochrane Review (CD010351) we used a theory driven mixed-method approach. Evidence was sought through traditional database searches and, reflecting the origin of much of the evidence, through extensive searches of grey literature and direct contact with over 200 relevant organisations. Quantitative evidence was used to assess effectiveness, qualitative evidence to illuminate the processes and mechanisms contributing to the observed outcomes. Evidence was brought together to develop a conceptual model of impact with additional high-level evidence used to populate the potential pathways between intervention and impact.

Results: We identified 30 papers referring to 21 unique interventions from the UK, Australia and Canada. The evidence identified was unsuitable for meta-analysis; we therefore used narrative synthesis which revealed limited quantitative evidence of positive impacts to health achieved, and qualitative evidence that allowed us to map potential mechanisms through which these might be achieved, as illustrated in the conceptual model (Fig. 1, Conceptual Model).

Conclusions: The theory driven mixed-method review approach facilitated a more comprehensive understanding of the potential of environmental enhancement interventions to promote health and wellbeing than may have been possible using traditional review methodologies. Theory driven mixed-method reviews may therefore have potential as an effective approach in the synthesis of evidence relating to complex interventions.