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

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 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: Types of Interventions

#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)

Acknowledgements 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.