Authors' objectives

The major aim was to examine the impact of primary prevention using meta-analytic procedures, in an attempt to identify variables that moderate programme outcomes. A second goal was to examine the types of outcomes achieved by preventive interventions.

Searching

The literature search involved a search of PsycLIT and a manual search of 15 journals that typically publish articles involving child and adolescent populations. To locate additional studies, the references from each identified study, from texts on prevention, and from various published articles were also examined. In a combined computer and handsearch of Dissertation Abstracts, 5 years between 1970 and 1990 were randomly selected and four volumes of abstracts were manually searched for each of the 5 years. Unpublished dissertations were obtained through interlibrary loans.

Study selection

Assessment of study quality

Each study was coded on various methodological features, e.g. randomised designs, the use of attention placebo controls, attrition rates, and outcome measures used. Three research assistants, employed over different time-periods, coded the studies for methodological features. To assess inter-rater reliability, 20 studies coded by each rater (approximately 40% of all the studies each had coded) were selected randomly and compared with those independently coded by the first author who had trained each assistant. The assistants did not know which studies were to be selected for reliability checks.

Data extraction

The authors do not state explicitly how the data were extracted. However, it was implied that various components of data extraction (e.g. how effect sizes were calculated, participant characteristics and outcome measures) were coded over different time-periods by three research assistants. Inter-rater reliability was also calculated using the same method as previously described (see 'Judgements of Validity' section).

Methods of synthesis

Results of the review

There were 177 interventions: 150 from published reports and 27 from unpublished doctoral dissertations. The total number of participants was not reported. However, 34% of the studies involved samples of 50 or less, and 29% involved samples of 100 or more.

Significant heterogeneity was reported (Q=327.40, p<0.0001).

The results were presented according to the programme type.

Environment-centred programmes: school-based centres yielded a mean ES of 0.35 (confidence interval, CI: 0.30, 0.43); the mean ES for parent-training was not significant.

Transition programmes: the mean ES was 0.36 (CI: 0.15, 0.56) for divorce, 0.39 (CI: 0.27, 0.58) for school entry or change, 0.87 (CI: 0.66, 1.07) fopr first-time mothers, and 0.46 (CI: 0.35, 0.58) for medical or dental procedures.

Person-centred programmes: the mean ESs ranged from 0.24 (CI: 0.18, 0.31) to 0.93 (CI: 0.66, 1.19); all were significant.

In practical terms, the average participant in a primary prevention programme surpasses the performance of between 59 and 82% of those in a control group, whilst outcomes reflect an 8 to 46% difference in success rates favouring prevention groups. Most categories of programme had the dual benefit of significantly reducing problems and significantly increasing competencies.

Authors' conclusions

Although several issues still have to be resolved, the outcome data indicated that most categories of primary prevention programme for children and adolescents produced significant effects. These finding provided empirical support for future research and practice in primary prevention.

CRD commentary

The authors presented a well-defined review question, and the inclusion criteria were clearly stated.

After various factors were examined for heterogeneity, the primary studies were combined appropriately.

The validity assessment involved the coding of various methodological features, but the authors did not state if they put this information to further use.

The authors did not state over what period they searched PsycLIT, or the search terms which were used. The handsearch of Dissertation Abstracts was limited to five randomly selected years between 1970 and 1990, and four volumes of the abstracts were manually searched for each of the five years. The search could have been extended to include all volumes of Dissertation Abstracts compiled from 1970 to 1990.

The descriptive characteristics of the reviewed studies were tabulated. The number of participants in each study was not reported, but this is likely to be due the large number of reviewed studies (n=177). The total number of participants was not reported.

The authors' conclusions seem to follow logically from the results.

Implications of the review for practice and research

Age was thought to have an important influence on the success rates of person-centred programmes (affective intervention and interpersonal problem-solving). It is possible that some other variable related to age, aside from cognitive developmental level, is important. Future research should systematically assess the participants' developmental competencies and relate them to outcome. There are several social-cognitive skills that are potentially relevant, such as role taking skills, interpersonal understanding, causal reasoning, and various cognitive mediational processes.

Future research should establish specific programme goals, clearly operationalise intervention procedures, and use theory to guide the intervention.

Funding

William T Grant Foundation, grant number 92-1475-92.

Bibliographic details

Durlak J A, Wells A M. Primary prevention mental health programs for children and adolescents: a meta-analytic review. American Journal of Community Psychology 1997; 25(2): 115-152. [PubMed: 9226860]

Other publications of related interest

Hedges LV, Olkin I. Statistical methods for meta-analysis. Orlando (FL): Academic Press; 1985.

Indexing Status

Subject indexing assigned by NLM

MeSH

Adolescent; Adolescent Health Services /standards; Child; Child Behavior Disorders /prevention & control; Child Health Services /standards; Child, Preschool; Humans; Mental Health Services /standards; Primary Prevention /standards; Research Design; Social Problems /prevention & control; Treatment Outcome

AccessionNumber

11997003504

Database entry date

31/08/1999

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.