A total of fifteen studies were included for review (3 randomized, controlled trials (RCT) and 12 non-randomized, comparative studies) that met selection criteria. In one of the RCT’s (Sallows and Graupner, 2005), children in both the experimental and control groups improved significantly over time, but there was no statistically significant difference between groups. Another RTC (Smith, 2000), found significantly better cognitive and communication skills in the experimental group but no difference in adaptive skills. A more comprehensive and better constructed study, the Early Start Denver Model (Dawson et al, 2009) found significant improvement in IQ, language, and adaptive behavior in toddlers (18 to 30 months) who received 20 hours per week of therapy for 2 years compared to a control group of children who received community available therapy. Diagnostic assignment also improved significantly in the experimental group (29% improved from autistic disorder to PDD), but no significant change in ADOS severity scores.
The non-randomized, comparative studies include the seminal study by Lovaas et al (1987; McEachin, 1993). While these original studies involved a clinic-based ABA therapy program, other studies have compared home-based, community-based, school-based, residential, and outpatient programs. All of the studies were small, involved children between 15 months to 7 years of age, and utilized IBI at a high level (Lovaas, 40 hours/week of in center, therapist let treatment). They reported significant improvement in 47% of children with subsequent follow-up (McEachin, 1993) durable improvement sustained for 5 years. This study had a number of serious flaws: small sample size (n=59), no randomization, selection bias (exclusion of low-functioning autistic children), non-standard endpoints, focus on IQ and school placement overlooked other important social and behavioral impairments, and important differences in male:female ratios. In addition, review has suggested that a select subgroup of children were responsible for the overall changes in the intervention group: the 9 individuals described as “normal functioning” after treatment had a mean IQ gain of 37 points compared to the other 10 members of the intervention group who had a mean gain of only 3 points. Others note that this degree of improvement has not been replicated in any other subsequent study. Overall this research has been criticized for producing unrealistic expectations about the ability of EIBI to help ASD children attain normal developmental status.
In 2004, Shea noted that the results of these early studies have been misstated and misinterpreted by advocates of EIBI and called upon professionals to acknowledge that while EIBI may be beneficial in some ASD individuals, there is no evidence to point to “recovery” or cure. A systematic review by Bassett et al (2000) concluded that while many forms of EIBI benefit ASD, “there is insufficient, scientifically-valid effectiveness evidence to establish a causal relationship between a particular program of intensive, behavioral treatment, and the achievement of ‘normal functioning’.”
Within this category, [EIBI] report shows greater improvements in cognitive performance, language skills, and adaptive behavior skills than broadly defined eclectic treatments available in the community. However, strength of evidence is currently low. Further, not all children receiving intensive intervention demonstrate rapid gains, and many children continue to display substantial impairment. Although positive results are reported for the effects of intensive interventions that use a developmental framework, such as the Early Start Denver Model (ESDM), evidence for this type of intervention is currently insufficient because few studies have been published to date.
Less intensive interventions focusing on providing parent training for bolstering social communication skills and managing challenging behaviors have been associated in individual studies with short-term gains in social communication and language use. The current evidence base for such treatment remains insufficient, with current research lacking consistency in interventions and outcomes assessed.
Although all of the studies of social skills interventions reported some positive results, most have not included objective observations of the extent to which improvements in social skills generalize and are maintained within everyday peer interactions. Strength of evidence is insufficient to assess effects of social skills training on core autism outcomes for older children or play-and interaction-based approaches for younger children.
In summary, while there is some evidence to support the premise that EIBI promotes gains in cognitive function, language skills, and adaptive behavior in young children with autism, overall the quality and consistency of results of this research are weak. Weaknesses in research design and analysis coupled with inconsistent results lead to important questions about the benefit of an expensive and intensive intervention. There is a need for larger, RTC studies to clarify the uncertainty about the effectiveness of EIBI for ASD. Until better research is completed, EIBI does not meet the Primary Coverage Criteria for evidence of effectiveness.
The Agency for Healthcare Research and Quality published (AHRQ, 2011) an evaluation of therapies for children with ASD between the ages of 2-12 focusing on treatment outcomes. They noted only 2 RCT’s with only one rated as good quality. They concluded that: “Some behavioral and educational interventions that vary widely in terms of scope, target, and intensity have demonstrated effects, but the lack of consistent data limits our understanding of whether these interventions are linked to specific clinically meaningful changes in functioning. The needs for continuing improvements in methodologic rigor in the field and for larger multisite studies of existing interventions are substantial. Better characterization of children in these studies to target treatment plans is imperative.” Similarly, a recent Cochrane review (Reichow, 2012) of EIBI for ASD noted: “There is some evidence that EIBI is an effective behavioral treatment for some children with ASD. However, the current state of the evidence is limited because of the reliance on data from non-randomized studies (CCT’s) due to the lack of RCT’s. Additional studies using RCT research designs are needed to make stronger conclusions about the effects of EIBI for children with ASD. The following clinical trial was identified from ClinicalTrials.gov: NCT00698997.
2019 Update
Annual policy review completed with a literature search using the MEDLINE database through November 2019. The key identified literature is summarized below.
Reichow et al (2018) published an update of a 2012 Cochrane review of the evidence for the effectiveness of early intensive behavioral intervention (EIBI) for young children with autism spectrum disorders (ASD). Effective outcomes included increased functional behaviors and skills, decreasing autism severity, and improving intelligence and communication skills for young children with ASD. Selection criteria were randomized control trials (RCTs), quasi-RCTs, and controlled clinical trials (CCTs) in which EIBI was compared to a no-treatment or treatment-as-usual control condition. The participants must have been less than six years of age at treatment onset and assigned to their study condition prior to commencing treatment. Five studies were identified (one RCT and four CCTs) with a total of 219 children: 116 children in the EIBI groups and 103 children in the generic, special education services groups. The age of the children ranged between 30.2 months and 42.5 months. Three of the five studies were conducted in the USA and two in the UK, with a treatment duration of 24 months to 36 months. All studies used a treatment-as-usual comparison group. The authors concluded that there was weak evidence that EIBI may be an effective behavioral treatment for some children with ASD. The authors reported that the strength of the evidence in the review was limited because the majority of the evidence came from small studies that were not of the optimum design. Due to the inclusion of non-randomized studies, the overall quality of evidence was rated as 'low' or 'very low' using the GRADE system. It is important that providers of EIBI are aware of the current evidence and use clinical decision-making guidelines, such as seeking the family’s input and drawing upon prior clinical experience, when making recommendations to clients on the use EIBI. Additional studies using rigorous research designs are needed to make stronger conclusions about the effects of EIBI for children with ASD.
The Agency for Healthcare Research and Quality (2017) published an update of a 2011 comparative effectiveness review on the effectiveness and safety of interventions targeting sensory challenges in children with autism spectrum disorder (ASD). Studies included in the review were those comparing interventions incorporating sensory-focused modalities with alternative treatments or no treatment. Studies had to include at least 10 children with ASD ages 2–12 years. Data was summarized qualitatively because of the heterogeneity of the data. Strength of evidence was also assessed. 24 unique comparative studies (17 newly published studies and 7 studies addressed in our 2011 review of therapies for children with ASD) were identified and included 20 randomized controlled trials (RCTs), 1 nonrandomized trial, and 3 retrospective cohort studies (3 low, 10 moderate, and 11 high risk of bias [ROB]). The review concluded that some interventions targeting sensory challenges may produce modest short-term (<6 months) improvements, primarily in sensory-related outcomes and outcomes related to ASD symptom severity; however, the evidence base for any category of intervention is small, and durability of effects beyond the immediate intervention period is unclear. Sensory integration–based approaches improved outcomes related to sensory challenges (low SOE) and motor skills (low SOE), and massage improved sensory responses (low SOE) and ASD symptoms (low SOE). Environmental enrichment improved nonverbal cognitive skills (low SOE). Auditory integration–based approaches did not improve language outcomes (low SOE). Some positive effects were associated with other approaches studied (music therapy, weighted blankets), but findings in these small studies were not consistent (insufficient SOE). Data on longer term results are lacking, as are data on characteristics that modify outcomes, effectiveness of interventions across environments or contexts, and components of interventions that may drive effects. In sum, while some therapies may hold promise and warrant further study, substantial needs exist for continuing improvements in methodologic rigor in the field.
Touzet et al (2017) published an article describing a randomised controlled trial on the impact of the Early Start Denver Model on the cognitive level of children with autism spectrum disorder (ASD). The study was a multicenter (4 centers in France, 1 center in Switzerland and 1 center in Belgium), randomized, controlled, single blind trial using a modified Zelen design. Children aged 15-36 months, diagnosed with ASD and with a developmental quotient (DQ) of 30 or above on the Mullen Scale of Early Learning (MSEL) were included. Expected enrollment is 180 children (120 in the control and 60 in the intervention group). The experimental group will receive 12 hours per week ESDM by trained therapists 10 hours per week in the centre and 2 hours in the toddlers' natural environment (alternating between the therapist and the parent). The control group will receive care available in the community. The primary outcome will be the change in cognitive level measured with the DQ scored at 2 years. Secondary outcomes will include change in autism symptoms, behavioral adaptation, communicative and productive language level, sensory profile and parents' quality of life. The primary analysis will use the intention-to-treat principle. As of April 2019, this clinical trial (NCT02608333) was still recruiting with an estimated completion date of September 30, 2021.
Mohammadzaheri et al (2015) published the results of a randomized control trial that compared two intervention conditions, a naturalistic approach, Pivotal Response Treatment (PRT) with a structured ABA approach on disruptive behavior during language intervention in the public schools. A Randomized Clinical Trial (RCT) design was used with the two groups of children that were matched according to age, sex and mean length of utterance. Thirty elementary school children (18 boys and 12 girls), ages 6 to 11 years old, participated in this study. Each child was diagnosed with autism by a child psychiatrist according to the DSM-IV-TR (American Psychiatric Association, 2000) and was referred the to the Hamaden University of Medical Sciences and Health Services in Iran for autism intervention. The data showed that the children demonstrated significantly lower levels of disruptive behavior with the PRT method of treatment.
Pickles et al (2016) published the results of a long-term follow-up of a randomized controlled trial on parent-mediated social communication therapy for young children with autism. This study was a follow-up of the Preschool Autism Communication Trial (PACT) to investigate whether the PACT intervention had a long-term effect on autism symptoms and continued effects on parent and child social interaction. PACT was a randomized controlled trial of a parent-mediated social communication intervention for children aged 2-4 years with core autism. Follow-up ascertainment was done at three specialized clinical centers in the UK (London, Manchester, and Newcastle) at a median of 5.75 years from the original trial endpoint. The main blinded outcomes were the comparative severity score (CSS) from the Autism Diagnostic Observation Schedule (ADOS), the Dyadic Communication Assessment Measure (DCMA) of the proportion of child initiations when interacting with the parent, and an expressive-receptive language composite. All analyses followed the intention-to-treat principle. PACT is registered with the ISRCTN registry, number ISRCTN58133827. 121 (80%) of the 152 trial participants were traced and consented to be assessed between July 2013, and September 2014. Mean age at follow-up was 10.5 years. The authors purported that the results were the first evidence to show long-term symptom reduction after a randomized controlled trial of early intervention in autism spectrum disorder. They support the clinical value of the PACT intervention and its implications on developmental theory.
2021 Update
Policy review completed with a literature search using the MEDLINE database through October 2021. No new literature was identified that would prompt a change in the coverage statement.
2022 Update
Annual policy review completed with a literature search using the MEDLINE database through October 2022. No new literature was identified that would prompt a change in the coverage statement.
2023 Update
Annual policy review completed with a literature search using the MEDLINE database through October 2023. No new literature was identified that would prompt a change in the coverage statement.
2024 Update
Annual policy review completed with a literature search using the MEDLINE database through November 2024. No new literature was identified that would prompt a change in the coverage statement.