Eating Disorder Prevention Programs: A Meta-Analytic Review

1. Eating Disorder Prevention Programs: A Meta-Analytic Review Eric Stice Heather Shaw Psychological Bulletin (2004) Susan Himes-Clinical

2. Research Domain • Eating pathology is defined as threshold and subthreshold • anorexia nervosa • bulimia nervosa • binge eating disorder Susan Himes-Clinical

3. Potential Antecedents or Consequences • Eating disturbance: • presents a chronic course • associated with distress and impairment • associated with inpatient hospitalization, suicide attempts, and mortality • associated with increased risk for future onset of obesity, depression, anxiety disorders, substance abuse, and health problems Susan Himes-Clinical

4. Three Generations of Prevention Programs • The 1st generation • Treatment: psychoeducational material • Sample: all adolescents • The 2nd generation • Treatment: psychoeducational material with focus on resisting sociocultural pressures for thinness and promoted healthy weight-control behaviors • Sample: all adolescents • The 3rd generation • Treatment: interactive exercises that focus on risk factors predicting eating pathology • Sample: selected target group of high-risk adolescents Susan Himes-Clinical

5. Research Questions • (1) The authors propose to summarize the prevention programs and their effects • (2) They examine the sample, intervention, and design features associated with larger intervention effects • (3) The authors systematically consider the moderators associated with larger intervention effects • (4) They discuss theoretical, methodological, and statistical limitations of the literature and propose directions for future research Susan Himes-Clinical

6. Proposed Moderators • Risk status of participants (high risk) • Gender (female) • Age (15-19) • Treatment type (Interactive) • Number of sessions (Multi-sessions) • Program Content (address risk factors) • Use of Reliable Measures (more sensitive) Susan Himes-Clinical

7. Data Collection (1) • Computer search was performed by two research assistants and a professional librarian on PsycINFO, MEDLINE, Dissertation Abstracts International, and Cumulative Index to Nursing and Allied Health Literature for the years 1980-2003 using the following keywords: eating disorder, eating pathology, anorexia, anorexic, bulimia, bulimic, binge eating, prevention, preventive, and intervention. • Second, the tables of contents for two journals (International Journal of Eating Disorders, Journal of Consulting and Clinical Psychology) that regularly publish eating disorder interventions were reviewed for the same time period. Susan Himes-Clinical

8. Data Collection (2) • Third, the reference sections of all identified articles, review chapters, and books in the area were examined. • Fourth, eating disorder prevention researchers were contacted and asked for copies of unpublished articles. • Although the authors did not exhaust every method of literature collection (conference proceedings, listserves, websites), the review system was thorough. Susan Himes-Clinical

9. Inclusion/Exclusion Criteria (1) • Prevention trials that tested for intervention effects on eating pathology • Also prevention trials that solely tested for intervention effects on risk factors that have been found to predict onset of eating pathology • Design: had to have random assignment with control groups (minimal-intervention/placebo/waitlist/assessment) or matched controls in quasi-experimental design • Studies without controls, studies that only assessed changes within the experimental group, and studies that included only posttest measures were excluded. Susan Himes-Clinical

10. Inclusion/Exclusion Criteria (2) • Sample size was listed but no studies were reported to be excluded due to size. • The authors do not address whether studies from other countries or other languages were included. • They do not address the specific measures used in each study (measures were coded as validated or non-validated and treated as moderators). • Publication type (article, book, chapter) wasn’t stated, and publication status (published/unpublished) was not listed. • Studies were not excluded due to effect size or moderator variables. Susan Himes-Clinical

11. Coding • The authors did not report number of raters, description of raters, rater training, or rater agreement/rater reliability. • To compute effect sizes, the authors chose to use the correlation coefficient “r” • 51 published and unpublished studies that met inclusion criteria; of the 51 studies, there were 38 different prevention trials (some were evaluated in more than one trial). This resulted in 60 separate effect sizes used in the analysis. Susan Himes-Clinical

12. Method • Procedure for calculating effect sizes followed Rosenthal (1991). • The random effects SPSS macro developed by Lipsy and Wilson (2001) was used to estimate weighted average effect sizes. Susan Himes-Clinical

13. Heterogeneity • The authors tested whether there was significant heterogeneity in the effect sizes for each outcome with the random-effects Q test using the SPSS macro. • If there was significant heterogeneity, univariate models tested whether the moderators were related to observed effect sizes using the random effects SPSS macro for inverse variance weighted regression with maximum likelihood estimation. • The authors tested whether there was significant residual heterogeneity in effect sizes after the moderators were entered into the multivariate models; the process was computed separately for post-test and follow-up. Susan Himes-Clinical

14. Results Susan Himes-Clinical

15. Results Susan Himes-Clinical

16. Results • Some prevention programs were found to decrease eating pathology, decrease risk factors for eating problems, and some program effects persisted for 2 yrs. • Larger intervention effects for: • Selected high risk samples vs. universal programs • Interactive vs. didactic programs • Multi-session vs. one hour programs • Interventions using validated measures • Females older than 15 Susan Himes-Clinical

17. Threats to Validity • Grouping of unsimilar measures to evaluate constructs (apples and oranges.) • The inclusion of studies that use unreliable/ invalid measures introduce error, possibly attenuating effect sizes. • In the most promising 3rd generation of prevention trials, some samples were small and there were not many studies, particularly with the primary target audience (high school girls) Susan Himes-Clinical

18. Overall Assessment • excellent examination of the effectiveness of eating disorder prevention trials • addressed subthreshold and threshold eating disturbance as well as well-established risk factors that mediate eating problems • quite comprehensive data collection efforts • used rigorous inclusion criteria (controlled trials, control groups, control for Time 1) • used appropriate data analysis methods Susan Himes-Clinical

19. Overall Assessment • The authors did make some mistakes • underreported coding techniques and never addressed inter-rater reliability • didn’t use bias reduction techniques or address outliers • never reported confidence intervals, variance • did not display their findings in graphic form • did not exclude studies with non-valid, unreliable measures Susan Himes-Clinical