This section includes a summary of all studies identified through the literature search described previously, along with recent systematic reviews relevant to each category.
2.3.1 Comprehensive interventions
This category of interventions includes a range of services that aim generally to provide a comprehensive model of intervention. Results of individual studies and systematic reviews are presented in Table 1. These interventions vary widely in intensity, direct focuses on the child, and treatment philosophy but are similar in terms of breadth of goals across areas of functioning. Studies included in this section include research on the following interventions:
behavioural interventions that are grounded in learning theory such as applied behavioural intervention (ABI), early intensive behavioural intervention (EIBI)
developmental interventions that focus on child development and building positive relationships
combined interventions, sometimes known as ‘eclectic interventions’ that combine elements of behavioural and developmental models and take account of evolving knowledge about autism and typical development.
Table 1: Review of recent (2005–May 2011) research literature into outcomes of early intervention for autism – comprehensive interventions
Studies evaluated for this review
Quality and outcomes
Dawson, G., Rogers, S., Munson, J., Smith, M., Winter, J., Greenson, J. et al. (2010). Randomized, controlled trial of an intervention for toddlers with autism: the Early Start Denver Model. Pediatrics, 125(1), e17–23.
Good quality study (4.025) of the Early Start Denver Model (ESDM), compared with eclectic intervention. EDSM blends ABA principles with developmental and relationship-based approaches for young children, and is generally delivered intensively. Found significant improvements in IQ, language, adaptive behaviour, and autism diagnosis. This study needs replication to strengthen conclusions.
Lydon, H., Healy, O. & Leader, G. (2011). A comparison of Video Modelling and Pivotal Response Training to teach pretend play skills to children with Autism Spectrum Disorder. Research in Autism Spectrum Disorders, 5, 872–884.
Pivotal Response Training (PRT) vs. video modelling. Good quality study (3.675) though very small numbers. Measured ‘play actions’ and verbalisations. Significant increase in play actions pre-post for both conditions, but greater increase for PRT. No difference between groups for verbalisations.
McConkey, R., Truesdale-Kennedy, M., Crawford, H., McGreevy, E., Reavey, M. & Cassidy, A. (2010). Preschoolers with autism spectrum disorders: Evaluating the impact of a home-based intervention to promote their communication. Early Child Development and Care, 180(3), 299–315.
Low quality study (SMRS 2.61), some beneficial outcomes reported. Eclectic approach including TEACCH, + PECS + Hanen delivered over 9 months in home visits. Treatment group showed improvements on Psycho-Educational Profile (PEP-R) across many developmental areas; however data were not collected on the control group. Significant improvements on communication and daily living scales on Vineland. Poorly reported parental outcomes. Both groups increased in autism severity.
Peters-Scheffer, N., Didden, R., Mulders, M. & Korzilius, H. (2010). Low intensity behavioural treatment supplementing preschool services for young children with autism spectrum disorders and severe to mild intellectual disability. Research in Developmental Disabilities, 31(6), 1678–1684.
Good quality study (SMRS 3.54) of combined intervention (a group program using TEACCH principles, plus individual treatment using Lovaas style ABA), compared with no treatment (normal preschool program). Significant positive outcomes for developmental age and adaptive skills. No difference for ASD severity or for behaviour.
Roberts, J., Williams, K., Carter, M., Evans, D., Parmenter, T., Silove, N., Clark, T. & Warren, A. (2011). A randomised controlled trial of two early intervention programs for young children with autism: Centre-based with parent program and home-based. Research in Autism Spectrum Disorders, 5, 1553–1566.
Good quality random clinical trials (RCT) (SMRS 3.65) comparing an eclectic home based treatment with centre based, and a control group (waitlist, treatments as usual). Mixed outcomes: centre based outcomes generally slightly better than home-based but the need for range of programs to suit different families/children noted.
Smith, I.M., Koegel, R.L., Koegel, L.K., Openden, D.A., Fossum, K.L. & Bryson, S.E. (2010). Effectiveness of a novel community-based early intervention model for children with autistic spectrum disorder. American Journal on Intellectual & Developmental Disabilities. 115(6), 504–523.
Good quality study (SMRS 4.19), though with no comparison group so outcomes are difficult to interpret. Both higher and lower functioning children were included. The intervention combines parent training and naturalistic one-to-one behaviour intervention employing PRT. Outcomes included: significant improvements in communication (measured on formal assessment), for all children, with greater improvement for children with IQ greater than 50. Significant gains in cognitive age for cohorts combined, decrease in autism symptoms for group with higher IQ scores.
Zachor, D.A, Itzchak, E.B., Rabinovich, A.-L., Lahat, E. (2007). Change in autism core symptoms with intervention. Research in Autism Spectrum Disorders. 1(4), 304–317.
Good quality study (SMRS 3.88) comparing ABA with an eclectic developmental program. Autism outcomes (measured by ADOS) = improvement in communication domain significant for ABA group, not significant for the ED group. Both groups improved on the social domain but the ABA group had a larger clinical effect. No differences in cognitive ability between groups.
Zachor, D.A. & Itzchak, E.B. (2010). Treatment approach, autism severity and intervention outcomes in young children. Research in Autism Spectrum Disorders, 4(3), 425–432.
Good quality study (SMRS 3.36) comparing centre-based ABA with centre-based eclectic program. Non-randomised but groups were similar pre-treatment. Both treatments provided similar hours and intensity but differed in philosophy, model, and parent involvement. Groups both showed improvements with no difference between groups.
Summary of systematic reviews of treatments
Eikeseth, S. (2009). Outcome of comprehensive psycho-educational interventions for young children with autism. Research in Developmental Disabilities,30(1), 158–178.
Overall outcome: Twenty studies evaluated behavioural treatment, 3 studies evaluated TEACCH and 2 studies evaluated the Colorado Health Sciences Project. ABA treatment was demonstrated to be effective in enhancing global functioning in pre-school children with autism when treatment is intensive and carried out by trained therapists (one Level 1 study, four Level 2 studies).
Eldevik, S., Hastings, R.P., Hughes, J.C., Jahr, E., Eikeseth, S. & Cross, S. (2010). Using participant data to extend the evidence base for intensive behavioural intervention for children with autism. American Journal on Intellectual & Developmental Disabilities, 115(5), 381–405.
Behavioural intervention can achieve reliable change in IQ and adaptive behaviour compared with less intensive interventions.
IQ and adaptive behaviour at intake predict gains in adaptive behaviour. Intensity of intervention can predict gains in both IQ and adaptive behaviour.
Makrygianni, M.K. & Reed, P. (2010). A meta-analytic review of the effectiveness of behavioural early intervention programs for children with autistic spectrum disorders. Research in Autism Spectrum Disorders, 4(4), 577–593.
Behavioural early intervention programs can improve children’s language comprehension, communication skills, and socialisation, as well as intellectual abilities.
Behavioural early intervention programs are much more effective than eclectic (control) programs in improving intellectual, language, and adaptive behaviour abilities of children with ASD.
Factors found to be correlated with the effectiveness of the behavioural programs were: intensity and duration of the programs; inclusion of parental training, as well as the age and the adaptive behaviour abilities of the children at intake.
Intensity of 25 hours/week was associated with a strong effect size (0.7) for all outcomes but no further effect was found for interventions of more than 25 hours/week.
Magiati, I., Moss, J., Charman, T. & Howlin, P. (2011). Patterns of change in children with Autism Spectrum Disorders who received community based comprehensive interventions in their pre-school years: A seven year follow-up study. Research in Autism Spectrum Disorders, 5(3), 1016–1027.
Overall outcome: Review aimed at tracking patterns of change longitudinally, as a result of a broad range of interventions. There are no comparisons of intervention groups against control groups, or against each other. Does not shed any light on the efficacy of particular interventions.
Peters-Scheffer, N., Didden, R., Korzilius, H. & Sturmey, P. (2011). A meta-analytic study on the effectiveness of comprehensive ABA-based early intervention programs for children with Autism Spectrum Disorders. Research in Autism Spectrum Disorders, 5(1), 60–69.
Overall outcomes: EIBI group out-performed the control group on all dependent variables.
Interpret results cautiously as there was publication bias identified with the expressive language outcome studies and quite high statistical heterogeneity. This was possibly due to differences in characteristics of the treatment (setting, amount of supervision), participants (age at treatment onset, IQ at treatment onset, diagnosis) and methodological problems (small sample sizes, non-randomised approaches, non-uniform assessment tools, quasi-experimental designs, lack of equivalent groups, lack of adequate fidelity, selection bias, and comparison group differences).
Odom, S.L., Boyd, B.A., Hall, L.J. & Hume, K. (2010). Evaluation of comprehensive treatment models for individuals with autism spectrum disorders. Journal of Autism and Developmental Disorders, 40(4), 425–436.
Thirty comprehensive treatment models (CTM) were identified, the majority based on an applied behaviour analysis framework, although a substantial minority followed a developmental or relationship-based model. As a group, CTMs were strongest in the operationalisation of their models, although relatively weaker in measurement of implementation, and with some notable exceptions, weak in evidence of efficacy.
Virues-Ortega, J. (2010). Applied behaviour analytic intervention for autism in early childhood: meta-analysis, meta-regression and dose-response meta-analysis of multiple outcomes. Clinical Psychology Review, 30(4), 387–99.
Overall outcomes: Long-term, comprehensive ABA intervention leads to (positive) medium to large effects in terms of intellectual functioning, language development, and adaptive behaviour of individuals with autism. Although favourable effects were apparent across all outcomes, language-related outcomes (IQ, receptive and expressive language, communication) were significantly superior to non-verbal IQ, social functioning and daily living skills outcomes, with effect sizes approaching 1.5 for receptive and expressive language and communication skills.
2.3.2 General summary of current research evidence for comprehensive interventions
The findings of the current literature review support the findings of previous reviews. Behaviourally based interventions, and specifically those that are intensive (often referred to as applied behavioural analysis (ABA) or early intensive behavioural intervention (EIBI)), continue to indicate some positive outcomes for some children in a range of areas including cognitive skills, communication, and adaptive behaviour. It is important to note, however, that outcomes vary among studies and between individual children, and that there is still limited information about which children with an ASD are most likely to benefit from behavioural interventions. Recent studies comparing intensive behavioural interventions with eclectic interventions that were delivered with similar levels of intensity, found that children in both groups made significant improvements and that the groups did not differ significantly. A study of an intensive developmental approach also indicated significant improvements in IQ, language, adaptive behaviour, and autism diagnosis for some young children with autism, though more studies of this model are required.
The current research also included a number of studies evaluating a range of eclectic programs and interventions, such as TEACCH and Building Blocks, which measured a range of outcomes. Findings from new research and systematic reviews generally indicated positive outcomes. These outcomes included improvements in developmental age and adaptive skills for children involved in a combined TEACCH and ABA program, though no differences were found in ASD severity or behaviour, and there were mixed outcomes for a randomised controlled trial that compared centre-based, home-based and control groups, with centre-based outcomes generally slightly better than home-based. These findings show similarities to those of theComparative Effectiveness Review (Warren et al. 2011) in the small number of studies of mixed quality, though with generally positive outcomes in a range of areas.
It is likely that intensity of intervention and parental involvement play a role in the effectiveness of intervention programs. The need for a range of programs to suit the needs of different children and families is also noted, given that no single intervention resulted in the same outcomes for all children studied. Results of this up- to-date review, incorporating the most recent research findings extend and are essentially consistent with findings from the previous review of Roberts and Prior (2006).