RESUMEN
BACKGROUND: Interpersonal violence can significantly reduce adolescents' opportunities for becoming happy and healthy adults. Central America is the most violent region in the world and it is estimated that adolescents are involved in 82% of all homicides in this region. Family skills training programmes have been designed to prevent interpersonal violence in adolescents. Several studies in high-income countries suggest they are effective. However, there are no published trials assessing effectiveness of these programmes in low- and middle-income countries (LMIC). The aim of this study is to test the effectiveness of the Strengthening Families Programme 10-14 (SFP 10-14 or "Familias Fuertes") in Panama, a LMIC in Central America. An embedded process evaluation will examine the extent to which the intervention is delivered as intended, variation across trial sites, influences on implementation and intervention-context interactions. Cost-effectiveness will also be assessed. METHODS: This is a cluster randomised controlled trial. The 28 townships with the highest homicide rates in Panama will be randomly allocated to implementation of SFP 10-14 alongside services-as-usual or to services-as-usual only. Approximately 30 families will be recruited in each township, a total sample of 840 families. Families will be assessed at baseline, approximately eight weeks after baseline (i.e. post intervention), six months and 12 months after. The primary outcome measure will be the parent reported externalising subscale of the Child Behaviour Checklist at T3 (i.e., which is approximately 12 months after baseline). For the process evaluation, recruitment, attendance, fidelity and receipt will be measured. Qualitative interviews with facilitators, trainers, parents and adolescents will explore barriers/facilitators to implementation and intervention receipt. For the cost-effectiveness analysis, service use information will be gathered from parents and adolescents with a three-month recall period. Costs and consequences associated with implementation of the intervention will be identified. DISCUSSION: This trial will be the first to evaluate SFP 10-14 in a LMIC. Results have the potential to guide public policies for the prevention of interpersonal violence in Central America and beyond. TRIAL REGISTRATION: ISRCTN Registry, 14023111 . Registered on 13 July 2017.