Background Young people in the UK have among the worst health in Europe with marked inequalities across the social scale. Substance use and violence are highly prevalent and damaging to young people’s long-term health. There are increasing calls for adolescent health interventions to address multiple rather than single risk behaviours because such behaviours cluster together and because such interventions are potentially more feasible and efficient. Positive youth development (PYD) is one such intervention to address inter-clustered risk behaviours among young people. The National Youth Agency defines such interventions as voluntary and informal educational activities aiming to bring about generalised youth development in terms of positive assets such as skills, relationships and confidence, rather than merely remedying ‘problem behaviours’. We systematically reviewed outcome evaluations testing the effectiveness of PYD interventions on preventing substance use and violence in young people.
Methods We included studies where the majority of participants were aged 11–18 years and where interventions were delivered in community (not clinical or judicial) settings outside of normal school hours. We excluded studies targeting populations on the basis of pre-defined physical and mental health conditions or targeting parents/carers alongside young people in order to focus on family functioning. We searched 19 databases. Two reviewers working independently screened records, assessed full-text studies for inclusion, and extracted data. In order to include all relevant effect sizes in each model, we estimated multilevel meta-analyses for substance use outcomes and violence outcomes. GRADE was used to evaluate our findings.
Results We found 13 study reports of 10 distinct outcome evaluations and included 12 reports of 9 distinct evaluations in our meta-analyses. Included studies were of three categories of intervention: after-school interventions; multi-component interventions; and mentoring-driven interventions. Our meta-analyses found a small effect for substance use outcomes overall that was significant neither statistically nor in terms of public health relevance. Meta-analyses suggested that PYD interventions did not have a statistically significant effect on violence outcomes across all time points. Evidence was rated ‘very low’ for each outcome.
Discussion Our meta-analyses do not offer evidence of PYD interventions in general having effects of public health significance in reducing substance use and violence among young people. Evaluations did not consistently report intervention theories of change or data on implementation fidelity, so we are cannot determine whether our meta-analyses should be interpreted as providing evidence that, in general, the PYD theory of change is ineffective in reducing substance use and violence among young people.
- child and adolescent development
- substance use
- systematic reivew