Family-based Prevention of Offending: A Meta-Analysis David P. Farrington & Brandon C. Welsh 2003 Jenna Ayers Radford University

Overview  Review of the effectiveness of family-based prevention programs in reducing offending and antisocial behavior by children and adolescents.  Family-based programs typically target family risk factors.  Goal: aims to prepare and maintain systematic reviews and to make them available electronically.

Previous Research  Narrative reviews of effect of family-based interventions to prevent delinquency and later criminal offending  Serketich & Dumas (1996)  Cochrane review completed by Woolfenden, Williams, & Peat (2002)

Systematic Review Why?  Use rigorous methods for: locating, appraising, and synthesizing evidence from evaluation studies  Explicit objectives  Explicit criteria for inclusion and exclusion of studies  Wide-ranging methods for searching for studies that are designed to reduce bias

Method  Selection of Evaluations (Inclusion)  1. The family and family factors  2. Outcome measure of delinquency or antisocial child behavior  3. High quality methodologically  4. Original sample size

Searching Strategies  Original aim: to update the review of family-based crime prevention in the 1997 Maryland Report  Began searches in 1997  1. Recent reviews  2. Articles in major journals  3. Youth Update  4. Contacts

Measuring Effect Size  Aimed to measure 4 different effects in each study:  1. Short-term effect on delinquency  2. Short-term effects on child antisocial behavior  3. Long-term effects on offending  4. Long-term effects on antisocial behavior

Main Measure of Effect Size The standardized mean difference d, which summarizes the difference between the experimental and control groups in standard deviation units:  D= (Mc-Me)/s  Positive value of d indicates a desirable effect of the intervention

Family-based Prevention Programs  Home Visiting (4)  Day Care/Preschool programs (5)  Parent Training programs (10)  School-based programs (7)  Home/Community programs with Older Children (8)  Multi-systemic Therapy Programs (6)

Meta-Analysis Mean Effect Sizes CategoryLow CIHigh CIMeanSig A /4 B /5 C /10* D /7 E /8 F /6* Total /40*

Mean Effect Sizes Delinquency Low CIHigh CIMeanSig Short-term /12 Long-term /10 Total /19* Antisocial behavior Short-term /26 Long-term /7 Total /27

Results of Meta Analysis  Suggest that prevalence of offending could be reduced by about 10-15% by implementing such programs.  More than half of all evaluations found a significant decrease in delinquency  Effects on delinquency persisted in long-term evaluation studies

Results  Most effective types of programs used behavioral parent training  Least effective were those based in schools  All other types of family-based programs were effective

Conclusions  40 of the highest quality family-based crime prevention programs were reviewed  Programs grouped into 6 categories  These family-based programs had desirable effects in reducing delinquency and antisocial child behavior

Future Research  More large-scale evaluations are needed using randomized experiments  Ideally, programs focusing more clearly and more narrowly on family risk factors should be implemented and evaluated  More efforts should be made to determine links in the causal chain between family processes and offending  More long term follow ups should be carried out to establish the persistence of effects

Future Research  Important to investigate why effect sizes are greater in smaller scale studies than in larger scale ones.  Future experiments needed that attempt to disentangle the different elements of successful programs  Know more about the economic efficiency of family-based crime prevention programs

Bottom Line  Existing evidence suggests that family-based prevention programs are effective in reducing offending.  More of these types of programs should be implemented and evaluated.