Family-based Prevention of Offending: A Meta-Analysis

1
Family-based Prevention of Offending A
Meta-Analysis

• David P. Farrington Brandon C. Welsh
• 2003
• Jenna Ayers
• Radford University

2
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.

3
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)

4
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

5
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

6
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

7
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

8
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

9
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)

10
Meta-AnalysisMean Effect Sizes
Category Low CI High CI Mean Sig
A .111 .360 .235 2/4
B .147 .371 .259 4/5
C .274 .517 .395 5/10
D -.014 .149 .068 3/7
E .056 .306 .181 3/8
F .281 .548 .414 2/6
Total .278 .269 .223 19/40
11
Mean Effect Sizes
Delinquency Low CI High CI Mean Sig
Short-term .132 .315 .224 5/12
Long-term .281 .464 .372 6/10
Total .250 .391 .321 10/19
Antisocial behavior
Short-term .157 .252 .204 11/26
Long-term .016 .201 .109 2/7
Total .146 .246 .196 11/27
12
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

13
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

14
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

15
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

16
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

17
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.

18
(No Transcript)