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The Behavioural/Developmental Continuum of Interventions for Autism Spectrum Disorders: A Systematic Review. Many Faces of Childhood Well Being: The Early Years November 30, 2007 Veronica Smith. The need for a systematic review: Quantity of the evidence.
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The Behavioural/Developmental Continuum of Interventions for Autism Spectrum Disorders: A Systematic Review Many Faces of Childhood Well Being: The Early Years November 30, 2007 Veronica Smith
The need to systematically review autism intervention: Cost (Ganz, 2007)
Previous Reviews • Review of reviews • 30 reviews on the effectiveness of behavioural and developmental interventions • 51% published after 2004; 2 published before 2000 • Focus: varies (i.e., most focus on one intervention type or core behaviour of autism) • 83% of the reviews suffered from one or major methodological quality concerns • Therefore, the reviews are: • vulnerable to bias that compromises their validity; • need to be interpreted with caution Krebs, J., et al., under review 2007
Purpose of our Systematic Review • #1 To identify… • The efficacy and effectiveness studies of interventions for children with autism • #2 To describe… • Participant characteristics, interventions, settings, and outcomes • #3 To evaluate… • Methodological quality of the studies and the quality of the evidence
Methods: Data Sources • Comprehensive searches of 22 electronic data bases of medical, educational, and psychological literature up to May 2007. • Other sources included hand searches, reference tracking, contact with authors, and contact with experts
Methods: Review Methods • Included studies: • Design • Clinical trials (RCT or CCT) • Observational analytic studies (retrospective or prospective) • Intervention • Any behavioural or developmental intervention for individuals diagnosed with ASD • Published in English • 2 independent reviewers assessed study relevance, extracted the data, and assessed the methodological quality of the studies
#1 Identify: Included Studies 86 Clinical trials 14 Retrospective or prospective cohorts
#2 Describe: ABA (31 studies) • Lovaas style therapy (UCLA Young Autism Project) or Intensive Behavioural Intervention or based or Discrete Trial methodology • Participants: total 770; median 20 per study • 27 included toddlers, 12 included school age; 4 included adolescents; 1 included adults • Only 6 studies indicated ethnicity • 13 reported autism severity; individuals with severe symptoms were included in 7 studies; 4 studies limited participants to mild-moderate; 13 reported verbal ability; 3 excluded nonverbal • Setting: community, home, clinic, research facilities, and school • Outcomes: 60% reported statistically significant results that favoured ABA therapy compared to comparison
#2 Describe: Contemporary ABA (12 studies) • Discrete trial and naturalistic procedures (e.g., natural reinforcers, incidental teaching) • Participants: 573 total; median 36 per study • 9 included toddlers; 8 included school age; 1 included adolescents • 3 studies indicated ethnicity • 2 studies reported level of severity; 2 studies included only verbal participants and 1 study included both verbal and non-verbal • Settings: • Community, clinic, and school • Outcomes: 100% of the studies reported statistically significant results that favoured Contemporary ABA
#2 Describe: Developmental Interventions (12 studies) • Application of developmental principles; child centered; examples of techniques: imitative interaction, DIR, responsive teaching • Participants: 256 total; median 20 per study • All included toddlers; 6 included school-age • 8 studies described ethnicity • Majority of studies did not report autism severity; 2 studies included only verbal; 6 included verbal and non-verbal • Settings: • Community setting, school, clinic, and research facilities • Outcomes: 83 % of the studies reported statistically significant results that favoured developmental interventions
#3 Evaluate: Quality Scales • Group Research Quality Indicators: • Clear description of participant characteristics • Description of intervention and interventionist (plus: measurement of treatment fidelity) • Description of comparison group condition • Outcomes clearly described • Statistical analysis (e.g., missing data analysis) and results reporting (e.g., effect sizes and confidence intervals) • Randomized control trials • Need to follow accepted randomization procedure, and provide a description of dropouts and withdrawals
Quality Scales Used • Jadad • 7 items (only five used for those studies that did not report using randomization) • Other scales used partially: • Schultz Concealment of Treatment Allocation Schultz et al. (1995) • Chalmers et al. (1981) • Detsky et al. (1992) • Smith et al. (2007)
#3 Evaluate: Quality of Studies • Generally, across all the criteria, the quality of the studies was poor • Significant threats to validity in every major category of quality • 83% failed to describe the participants adequately to replicate the sampling procedure • Quality of reporting of intervention variable; 32% monitored fidelity • Less than half (43%) reported independent outcome assessment • 54% reported sources of funding
#3 Evaluate: Comparisons across the studies • Five comparisons were possible due to variations in type of intervention, comparison groups, and outcomes of interest (i.e., only 13 of 101 studies used) • Two with clinically significant findings: • High vs low intensity Lovaas: favours high (outcome: intellectual functioning) • Lovaas vs Special Education: favours Lovaas (outcomes: intellectual functioning, adaptive behaviour, communication, overall language, and expressive language) (NB: poor quality of studies and limited number of groups decreases generalizability of these findings).
Implications • Researchers • Participant sampling: • Homogeneity vs sample size • Intervention description: • Treatment manuals • Fidelity • Comparison groups • Consider the inclusion of standard care as a treatment in the control group (i.e., treatment that is normally given) • Systematic use of outcomes
Implications • Practitioners & Policy Makers • Provision of intervention that addresses the core symptoms for autism is self evident • Many practices reported in the research have been demonstrated effective • Should be employed with caution and closely monitored until a greater accumulation of evidence is present
Next steps • More work to be done: • Systematically review the evidence contribution of single case research • Example of single case quality assessment • Reichow et al. (in press)
Funders: Alberta Centre for Child, Family and Community Research Collaborators: Alberta Centre for Child Health Evidence Principal Investigators: Brenda Clark, M.D. Veronica Smith, Ph.D. Research Team: Maria Ospina, M.Sc. (Project Manager) Lisa Hartling, M.Sc. Mohamed Karkhaneh, M.D. Jennifer Seida, B.H.Sc. Lisa Tjosvold, M.L.I.S. Denise Thomson, M.B.A Janine Odishaw, Ph.D. Ben Vandermeer, M.Sc. Acknowledgements