Authors' objectives

To determine the effectiveness of peer-delivered health promotion in promoting young people's health and to examine the characteristics of peer-delivered interventions which differentiate from teacher-delivered interventions. The review also aimed to determine the appropriateness of peer-delivered health promotion for young people and planned to summarise the current position with respect to implementing and evaluating a peer-delivered approach to health promotion for young people and to indicate future research, policy and practice needs.

Searching

Electronic databases searched included: MEDLINE, EMBASE, PsycLIT, ERIC, the Social Science Citation Index; specialised bibliographic registers (Bibliomap, the bibliographic register of the EPI-centre, the Cochrane Controlled Trials Register; HealthPromis, the bibliographic register of the Health Education Authority (England), and the bibliographic register of the Health Education Board (Scotland); the specialised bibliographies (the 'Europeer' Bibliography and the NIGZ Netherlands Institute for Health promotion and Disease prevention 'HIV/AIDS' prevention for Youth: Youth as Partners bibliography). Efforts were made to identify unpublished studies and handsearching of specialised journals was undertaken where possible. The dates and full search strategies used are given in the review. Only English language studies were included in the review.

Study selection

Assessment of study quality

The methodological quality of outcome evaluations was assessed according to seven criteria: clear definition of the aims of the intervention; a description of the study design and content of the intervention sufficiently detailed to allow replication; use of random allocation to the different groups including to the control or comparison group; provision of data on numbers of participants recruited to each condition; provision of pre-intervention data for all individuals in each group; provision of post-intervention data for each group; attrition reported for each group; findings reported for each outcome measure indicated in the aims of the study. The methodological quality of process evaluations was assessed according to eight criteria: an explicit account of the framework and/or the inclusion of a literature review was given; clearly stated aims and objectives; a clear description of context; a clear description of sample; a clear description of methodology, including systematic data collection methods; an analysis of the data by more than one researcher; and inclusion of sufficient original data to mediate between data and interpretation. Four core criteria were used to classify studies as 'sound' or 'not sound'. These were: employing a control/comparison group equivalent to the intervention group on socio-demographic and outcome variables; providing pre-intervention data for all individuals/groups as recruited into the evaluation; providing post-intervention data for all individuals/groups; reporting on all outcomes. How these criteria were selected and discussion of their suitability is included in the report. The methodological quality assessments for outcome and process evaluations were conducted by two reviewers independently and any disagreements were discussed and resolved, if necessary with a third reviewer.

Data extraction

Two reviewers extracted the data for outcome and process evaluations independently and any disagreements resolved through discussion. The categories of data included (but this is not necessarily an exhaustive list): study reference, country where conducted, population, setting, objectives (health focus), type of peer leaders (e.g. age relative to target group, how recruited, training received etc.), other providers involved, programme content, design of study, participant numbers, follow-up period, attrition rate, authors judgement of effect. Data regarding specific outcome measures appears not to have been extracted (no such data is presented in the report). Presumably, information pertaining to the quality assessments, described above, was also extracted.

Methods of synthesis

Results of the review

Of the 210 outcome or process evaluations included in the review, 49 outcome evaluations and 15 process evaluations met the criteria for inclusions and were fully reviewed. The total number of participants in the 12 'sound' outcome evaluation studies cannot be calculated, as this information is not presented for all studies. Of the nine studies that did provide this information the total number of participants in the review totalled 10698. These participants were distributed across intervention (peer-delivered), comparison (teacher-delivered) and control groups.

Of the 12 'sound' outcome evaluations, for all health foci, seven were effective for behavioural outcomes, three were effective for 'proxy outcomes', one was ineffective and one was unclear. Specifically, for sexual health, two were effective for behavioural outcomes and two were effective for 'proxy outcomes'. For smoking, three were effective for behavioural outcomes, one was ineffective and one was unclear. For asthma one was effective for 'proxy outcomes' only and for both violence prevention and testicular cancer, one study for each was effective for behavioural outcomes. Of the secondary education studies five were effective for behavioural outcomes one was effective for 'proxy outcomes', one was ineffective and one was unclear. Of the tertiary education studies, two were effective for proxy outcomes only and for studies in the community two were effective for behavioural outcomes only.

Of the 15 process evaluations the main results were as follows. In terms of acceptability, most young people expressed positive views on peer-delivered health promotion and negative views were rarely documented. In terms of implementation issues, conflict between the philosophy of peer education and the school environment was identified as a barrier and such organisational contexts made working with young people challenging. In terms of training, a main problem identified was the importance of ongoing support for peer educators.

Authors' conclusions

The current evidence base for peer-delivered health promotion is limited. Although the review did find some evidence for the effectiveness of peer-delivered health promotion in producing positive changes in health behaviour, a clear picture of success is still to be determined. In particular, much more work is needed in trying to gain a clearer understanding of the different processes involved in peer-delivered health promotion and how these relate to the success or otherwise of these interventions and to assess the extent to which success in one context is highly specific or could be generalised to other contexts and groups of young people. Further, while many studies placed a good deal of emphasis on the importance of various theories in developing effective health promotion, the exact contribution of these theories is still unclear.

CRD commentary

This review addressed an appropriate but very broad question. The inclusion criteria were clearly defined, although they were rather broad allowing inclusion of descriptions or discussions of peer-delivered health promotion interventions as well as more specific evaluations of interventions. The application of rigorous quality criteria (see below) did, however, reduce the number of studies to 12 outcome evaluations and 15 process evaluations. The strategy employed to identify all relevant studies was comprehensive and full details are presented in the report. Few unpublished studies were identified for inclusion in the report despite efforts made by the report authors. In addition, only English language studies were included. Thus the report's findings might be subject to some publication bias, the extent of which is unknown. The validity of studies included in the review was assessed by means of criteria derived from the literature. These criteria and a discussion of them are included in the report. The study selection, quality assessment and data extraction were all performed independently by two reviewers which should have reduced any author bias. Study details were only presented for the 12 'sound' outcome evaluations and the 15 'sound' process evaluations, and even then the amount of detail of the results presented in the report is minimal. The report addresses this to some extent by recommending that there is a need for more quantitative research and better reporting in this area. The narrative synthesis employed by the authors of this report is appropriate given the nature of the review question and the studies available. The conclusions drawn from the review appear to be supported by the information presented, however, much of the discussion relates to individual study findings rather than the pooled results of the review. This would suggest that either the synthesis of individual study results was not conducted as rigorously as it might have been, or that the scope of the review was too broad. The review was unable to identify the specific characteristics of a successful model of peer-delivered health promotion, which was one of the aims of the review.

Implications of the review for practice and research

Practice: Recommendations about effectiveness can only be made on the basis of individual studies. The authors conclude that using peer leaders to deliver health information does not automatically make an intervention more 'innovative' or more likely to be effective than other traditional health education strategies. The report also includes some recommendations about smoking prevention interventions and sexual health interventions, regarding some types of participants who are more likely to benefit from peer-delivered health promotion. Recommendations are also given on the type of participant recruited as a peer leader and on the method of recruitment. The evaluation should be of both the effect of the evaluation on the peer leader and on the peer group targeted. Further recommendations for developing and implementing health promotion for young people are also presented in the report.

Research: Studies of peer-delivered health promotion should employ rigorous research methodology (e.g. randomisation, quantitative analysis etc.) and reporting should be more comprehensive. Evaluative research should move towards the integration, rather than polarisation of qualitative and quantitative research techniques and of outcome and process evaluations. Recommendations for specific areas for future research into peer-delivered health promotion are also included in the report.

Funding

Department of Health

Bibliographic details

Harden A, Weston R, Oakley A. A review of the effectiveness and appropriateness of peer-delivered health promotion interventions for young people. London: University of London, Institute of Education, Social Science Research Unit, EPPI-Centre. 1999.

Original Paper URL

http://eppi.ioe.ac.uk/cms/Default.aspx?tabid=255

Other publications of related interest

Harden A, Oakley A, Oliver S. Peer-delivered health promotion for young people: a systematic review of different study designs. Health Ed J 2001;60(4):339-353

Indexing Status

Subject indexing assigned by CRD

MeSH

Adolescent; Child; Health Promotion /methods; Peer Group

AccessionNumber

12000008114

Database entry date

30/04/2001

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.