Abstract
IntroductionThe majority of adolescents do not meet guidelines for healthy behaviours, posing major risks for developing multiple non-communicable diseases. Unhealthy lifestyles seem more prevalent in urban than rural areas, with the neighbourhood environment as a mediating pathway. How to develop and implement sustainable and effective interventions focused on adolescent health and well-being in urban vulnerable life situations is a key challenge. This paper describes the protocol of a Youth-centred Participatory Action (YoPA) project aiming to tailor, implement, and evaluate social and physical environmental interventions.Methods and analysisIn diverse urban environments in Denmark, the Netherlands, Nigeria and South Africa, we will engage a dynamic group of 15–20 adolescents (12–19 years) growing up in vulnerable life situations and other key stakeholders (eg, policy makers, urban planners, community leaders) in local co-creation communities. Together with academic researchers and local stakeholders, adolescents will take a leading role in mapping the local system; tailoring; implementing and evaluating interventions during participatory meetings over the course of 3 years. YoPA applies a participatory mixed methods design guided by a novel Systems, User perspectives, Participatory co-creation process, Effects, Reach, Adoption, Implementation and Maintenance framework assessing: (i) the local systems, (ii) user perspectives, (iii) the participatory co-creation process, (iv) effects, (v) reach, (vi) adoption, (vii) implementation and (viii) maintenance of interventions. Through a realist evaluation, YoPA will explore why and how specific outcomes were reached (or not) in each setting (n=800–1000 adolescents in total).Ethics and disseminationThis study received approval from the ethics committees in Denmark, the Netherlands, Nigeria and South Africa and will be disseminated via various collaborative dissemination activities targeting multiple audiences. We will obtain informed consent from all participants. We envision that our YoPA co-creation approach will serve as a guide for participation of adolescents in vulnerable life situations in implementation of health promotion and urban planning in Europe, Africa and globally.Trial registration numberNCT06181162.