Using qualitative research to explore intervention mechanisms: findings from the trial of the learning together whole-school health intervention

Abstract Background This study reports on qualitative research conducted within a randomised controlled trial to explore possible intervention mechanisms. It focuses on the ‘Learning Together’ whole-school intervention delivered in secondary schools in England from 2014 to 2017 aiming to prevent bullying and aggression and improve student health. Intervention schools received staff training in restorative practice, a social and emotional learning curriculum, and an external facilitator and manual to convene and run a student/staff action group tasked with coordinating the intervention, focusing this on local needs. Methods Informed by realist approaches to evaluation, we analysed qualitative data to explore intervention mechanisms and how these might interact with school contexts to generate outcomes. Qualitative analysis drew on 45 interviews and 21 focus groups across three case-study schools and employed thematic content analysis to explore how intervention resources were taken up and used by local actors, how participants described the intervention mechanisms that then ensued, and how these might have generated beneficial outcomes. Results The thematic content analysis identified three social mechanisms that recurred in participant accounts: (1) building student commitment to the school community, (2) building healthy relationships by modelling and teaching pro-social skills, and (3) de-escalating bullying and aggression and enabling re-integration within the school community. Conclusions Our analysis provides in-depth exploration of possible mechanisms and the contextual contingencies associated with these, allowing refinement of the initial intervention theory of change. Trial registration ISRCTN registry 10751359. Registered on 11 March 2014