We identify specific preventative programmes with a good evidence base, through a rapid assessment of previous programme evaluations conducted by other “what works” clearinghouses, and from this seek to identify some common features – or “key principles” – associated with what does and doesn’t work.

Overall, we identified 67 well-evidenced programmes, all implemented in the US and nearly half in the UK, which aimed to prevent gang involvement, youth violence or associated problems such as youth offending, conduct disorder and delinquency. 54 of these programmes had been assessed as effective by the clearinghouses searched, while 13 were classified as ineffective.

The features and activities associated with these programmes were largely consistent with the findings of the key systematic reviews and evidence assessments identified through our literature review.