What theory, for whom and in which context? Reflections on the application of theory in the development and evaluation of complex population health interventions

Abstract

Recent years have seen a growing emphasis on the value of building and testing middle range theory throughout the development and evaluation of complex population health interventions. We agree that a coherent theoretical basis for intervention development, and use of evaluation to test key causal assumptions and build theory, are crucial. However, in this editorial, we argue that such recommendations have often been operationalised in somewhat simplistic terms with potentially perverse consequences, and that an uncritical assumption that an intervention explicitly based on theory is inherently superior carries significant risks. We first argue that the drive for theory-based approaches may have exacerbated a propensity to select ‘off-the-shelf’ theories, leading to the selection of inappropriate theories which distract attention from the mechanisms through which a problem is actually sustained. Second, we discuss a tendency toward over-reliance on individual-level theorising. Finally, we discuss the relatively slow progress of population health intervention research in attending to issues of context, and the ecological fit of interventions with the systems whose functioning they attempt to change. We argue that while researchers should consider a broad range of potential theoretical perspectives on a given population health problem, citing a popular off-the-shelf theory as having informed an intervention and its evaluation does not inherently make for better science. Before identifying or developing a theory of change, researchers should develop a clear understanding of how the problem under consideration is created and sustained in context. A broader conceptualisation of theory that reaches across disciplines is vital if theory is to enhance, rather than constrain, the contribution of intervention research. Finally, intervention researchers need to move away from viewing interventions as discrete packages of components which can be described in isolation from their contexts, and better understand the systems into which change is being introduced.

An assessment of physiotherapist’s delivery of behaviour change techniques within the SOLAS feasibility trial

“…In addition, given the group‐based nature of the intervention, future research would benefit from understanding the BCTs that were delivered to each individual participant to help identify which BCTs work for whom (Moore & Evans, ; Tate et al ., ). Furthermore, an investigation of participants’ receipt of these BCTs may help understand who benefits most from which BCTs (Borelli, ; Rixon et al ., ).…”

“…In addition, given the group-based nature of the intervention, future research would benefit from understanding the BCTs that were delivered to each individual participant to help identify which BCTs work for whom (Moore & Evans, 2017;Tate et al, 2016).…”

Adolescent self‐harm prevention and intervention in secondary schools: a survey of staff in England and Wales

“…To develop effective school-based prevention and intervention, it is first important to understand current practices. This is because, in alignment with the complex systems perspective, intervention can be seen as an attempt to disrupt existing system dynamics, where entrenched structures and resources may work to support or reject the introduction of a new approach (Fletcher et al, 2016;Keshavarz, Nutbeam, Rowling, & Khavarpour, 2010;Moore & Evans, 2017). A recent systematic review and meta-ethnography of international qualitative evidence on the role of schools in adolescent self-harm and suicide found that it is often not prioritised (Evans & Hurrell, 2016).…”

Contextual Factors Influencing the MAMAACT Intervention: A Qualitative Study of Non-Western Immigrant Women’s Response to Potential Pregnancy Complications in Everyday Life

“…Referring to Pawson and Tilley [26], Moore and Evans have argued that in order to understand how an intervention works in a specific context, a range of theoretical perspectives should be taken into consideration [35]. Consequently, we applied the theory by Alonzo [36] on situational-adaption to bodily signs and symptoms in order to illuminate and understand the mechanisms between the women's everyday life context and their actual response to potential pregnancy complications.…”