Peer-delivered health promotion for young people: A systematic review of different study designs

Objective To examine the effectiveness and appropriateness of peer- delivered health promotion for young people. Design Systematic review of experimental studies assessing impact on health outcomes and 'qualitative' studies evaluating intervention processes. Methods Studies were sought by searching electronic databases and hand searching. Those which met the review's inclusion criteria were assessed for methodological quality. Outcome evaluations were reviewed for four methodological qualities. Process evaluations were mapped according to criteria commonly used to establish the reliability and validity of 'qualitative' studies. Results Four hundred and thirty reports relevant to the topic area were identified. Two hundred and ten reported evaluations of peer-delivered interventions with 64 (49 outcome evaluations and 15 process evaluations) meeting the inclusion criteria. Only 12 (24 per cent) of the outcome evaluations were judged methodologically sound. Of these, seven found the method to be effective for at least one behavioural outcome. However, five sound studies directly compared the effectiveness of peers to other providers and found contradictory results. The majority of process evaluations examined the implementation ( n=9, 60 per cent) and acceptability of the method ( n=10, 67 per cent) and their findings provided insights into possible reasons for success or failure. Common methodological problems within studies included unclear details of sample and methodology suggesting that their conclusions may not be reliable. Conclusion The evidence for the effectiveness of peer-delivered health promotion for young people is not yet clear. Whilst the current evidence- base is able to suggest possible reasons for success or failure of this method, more systematic research into the conditions under which peer- delivered health promotion is effective in comparison to other methods of health promotion is needed. Integrating the evidence from experi mental studies and qualitative studies is complicated by the lack of standards for assessing reliability and validity in qualitative research.