A Process evaluation of the PLAN-A intervention (Peer-Led physical Activity iNtervention for Adolescent girls)

Background: Few adolescent girls engage in enough physical activity (PA) to meet recommendations and there is a need for new interventions to increase girls PA. We have previously published the results of the PLAN-A cluster randomised feasibility trial which was a peer-led school-based PA intervention, showing that the intervention was feasible and held promise to increase the PA of girls aged 12-13 years. In PLAN-A, pupils nominated by their peers as influential attend training to teach them how to influence, promote and normalise physical activity amongst their peer-group. This paper reports the results of the process evaluation of the PLAN-A feasibility study, specifically focussing on acceptability to key stakeholders, intervention fidelity, receipt/experiences and perceived effect and suggested intervention refinements before proceeding to a definitive RCT.Methods: A mixed-methods process evaluation triangulated data from qualitative focus groups and interviews with peer-supporter and non peer-supporter pupils (N=52), parents (N=12), teachers (N=6) and intervention training deliverers (N=5), quantitative questionnaires, and observations of intervention delivery. Quantitative data were analysed descriptively, and qualitative data were analysed with the Framework Method. Results: The duration, timings, content and delivery of the peer-supporter training were acceptable. There was good fidelity to the intervention manual and its underpinning theory including high fulfilment of session objectives and use of an autonomy-supportive motivational style. Peer-supporters engaged with and enjoyed the training and retained key peer-supporter messages (what counts as PA, encouragement, empathy and subtlety). Parents and teachers were supportive of the intervention and reported perceived effects including increased PA and awareness of it, improved peer relationships, and confidence. Suggested intervention refinements included increasing participatory learning, reducing technical jargon, and providing more support to overcome challenges to giving peer support.Conclusions: PLAN-A can be delivered as planned, is well-received, and appears to be effective in empowering adolescent girls to support their peer group to become more active. The refinements identified can be made within the original intervention structure, before proceeding to a definitive trial.