The influence of environmental factors on the generalisability of public health research evidence: physical activity as a worked example

摘要

Background: It is rare that decisions about investing in public health interventions in a city, town or other locationcan be informed by research generated in that specific place. It is therefore necessary to base decisions onevidence generated elsewhere and to make inferences about the extent to which this evidence is generalisable tothe place of interest. In this paper we discuss the issues involved in making such inferences, using physical activityas an example. We discuss the ways in which elements of the structural, physical, social and/or culturalenvironment (environmental factors [EFs]) can shape physical activity (PA) and also how EFs may influence theeffectiveness of interventions that aim to promote PA. We then highlight the ways in which EFs may impact onthe generalisability of different types of evidence.Discussion: We present a framework for thinking about the influence of EFs when assessing the generalisability ofevidence from the location in which the evidence was generated (place A) to the location to which the evidenceis to be applied (place B). The framework relates to similarities and differences between place A and place B withrespect to: a) the distributions of EFs; b) the causal pathways through which EFs or interventions are thought toexert their effect on PA and c) the ways in which EFs interact with each other. We suggest, using examples, howthis scheme can be used by public health professionals who are designing, executing, reporting and synthesisingresearch on PA; or designing/implementing interventions.Summary: Our analysis and scheme, although developed for physical activity, may potentially be adapted andapplied to other evidence and interventions which are likely to be sensitive to influence by elements of thestructural, physical, social and/or cultural environment such as the epidemiology of obesity and healthy weightpromotion.