Interventions for preventing eating disorders in children and adolescents.

BACKGROUND: Eating disorders represent an extremely difficult condition to treat and patients consume an enormous amount of mental health energy and resources. Being young, female, and dieting are some of the few identified risk factors that have been reliably linked to the development of eating disorders, and several prevention eating disorder prevention programs have been developed and trialed with children and adolescents. The purpose of this systematic review is to evaluate the effectiveness of eating disorder prevention programs for children and adolescents both in the general population and those determined to be at risk.

OBJECTIVES: 1. To determine if eating disorder prevention programs are effective in promoting healthy eating attitudes and behaviours in children and adolescents; 2. To determine if eating disorder prevention programs are effective in promoting psychological factors that protect children and adolescents from developing eating disorders; 3. To determine if eating disorder prevention programs are effective in promoting satisfactory physical health in children and adolescents; 4. To determine if eating disorder prevention programs have a long-term, sustainable, and positive impact on the mental and physical health of children and adolescents; and, 5. To determine the safety of eating disorder prevention programs in terms of possible harmful consequences on the mental or physical health of children and adolescents.

SEARCH STRATEGY: Relevant trials are identified through searching the Cochrane Controlled Trial Register (CCTR) and relevant biomedical and social science databases. All terms necessary to detect prevention programs and the participant groups are used. A strategy to locate randomised controlled trials is used. Other sources of information are the bibliographies of systematic and non-systematic reviews and reference lists from articles identified through the search strategy. In order to identify unpublished studies, experts in the field are contacted by letter and/or electronic mail.

SELECTION CRITERIA: Randomised controlled trials (RCT) with a major focus on eating disorder prevention programs for children and adolescents, where there is no known DSM-IV diagnosis of an eating disorder, are eligible for inclusion in the review. Trials must include a control group and at least one objective outcome measure (eg. BMI) or a standardised psychological measure used with the intervention and control group, pre- and post-intervention.

DATA COLLECTION AND ANALYSIS: A total of 1379 titles have been identified through the search to date. 13 studies were located that reported use of a randomised controlled trial methodology and were critically appraised by two independent reviewers. Five (5) studies were excluded as data were not reported in a useable form or useable data could not be obtained from the trial authors, one dissertation could not be obtained, one study had no "true" no-treatment or usual treatment control group, and one study did not use a pre-test outcome measure. Eight (8) studies met the selection criteria outlined above.

MAIN RESULTS: Only one of eight pooled comparisons of two or more studies using similar outcome measures and similar intervention types demonstrated the statistically significant effect of a particular type of eating disorder prevention program for children and adolescents. Combined data from two eating disorder prevention programs based on a media literacy and advocacy approach indicate a reduction in the internalisation or acceptance of societal ideals relating to appearance at a 3- to 6-month follow-up (Kusel, unpublished; Neumark-Sztainer2000) [SMD -0.28, -0.51 to -0.05, 95% CI]. However, there is insufficient evidence to conclude that this approach also demonstrated a significant impact on awareness of societal standards relating to appearance. There is insufficient evidence to support the effect of four programs designed to address eating attitudes and behaviours and other adolescent issues on body weight, eating disorder symptoms, associated eating disorder psychopathology or general psychological and physical well-being in the general sample or those classified as being at high risk for eating disorder (Buddeberg-F 1998; Killen 1993/1996; Santonastaso 1999; Zanetti 1999). Given only one program used a psychoeducation approach to prevent bulimia nervosa (Jerome, unpublished) and only one program adopted a focus on self-esteem (O'Dea 2000), the effect of these approaches could not be evaluated via meta-analyses. In relation to potential harmful effects, there is not sufficient evidence to suggest that harm resulted from any of the prevention programs included in the review.

REVIEWER'S CONCLUSIONS: The one significant pooled effect in the current review does not allow for any firm conclusions to be made about the impact of prevention programs for eating disorders in children and adolescents, although none of the pooled comparisons indicated evidence of harm. From a clinical perspective, the development and refinement of prevention programs is complicated by a lack of knowledge about risk factors associated with eating disorders and the need to strike a balance between delivering preventive interventions for eating disorders and considering the potential to cause harm. From a research perspective, the idea of "thresholds" for identifying young people at risk of developing eating disorders has been raised, and denial of concern or denial of illness represents a further issue complicating early identification in relation to eating disorder symptomatology. Longer-term effects of the intervention approaches will need to be monitored across development in order to demonstrate a decline in the incidence of eating disorders and associated risk factors.