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Pediatrics. Author manuscript; available in PMC 2016 July 19.
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Published in final edited form as:

Pediatrics. 2010 January ; 125(1): e17–e23. doi:10.1542/peds.2009-0958.

Randomized, Controlled Trial of an Intervention for Toddlers

With Autism: The Early Start Denver Model
Geraldine Dawson, PhDa,b,c, Sally Rogers, PhDd, Jeffrey Munson, PhDe,f, Milani Smith,
PhDe, Jamie Winter, PhDe, Jessica Greenson, PhDe, Amy Donaldson, PhDg, and Jennifer
Varley, MSe
aAutism Speaks
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bDepartment of Psychiatry, University of North Carolina, Chapel Hill, North Carolina

cDepartment of Psychology, University of Washington, Seattle, Washington
dMIND Institute, Department of Psychiatry, University of California Davis, Sacramento, California
eUniversity of Washington Autism Center, Center on Human Development and Disability,
University of Washington, Seattle, Washington
fDepartment of Psychiatry and Behavioral Sciences, University of Washington, Seattle,
Washington
gDepartment of Speech and Hearing Science, Portland State University, Portland, Oregon

Abstract
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OBJECTIVE—To conduct a randomized, controlled trial to evaluate the efficacy of the Early
Start Denver Model (ESDM), a comprehensive developmental behavioral intervention, for
improving outcomes of toddlers diagnosed with autism spectrum disorder (ASD).

METHODS—Forty-eight children diagnosed with ASD between 18 and 30 months of age were
randomly assigned to 1 of 2 groups: (1) ESDM intervention, which is based on developmental and
applied behavioral analytic principles and delivered by trained therapists and parents for 2 years;
or (2) referral to community providers for intervention commonly available in the community.

RESULTS—Compared with children who received community-intervention, children who

received ESDM showed significant improvements in IQ, adaptive behavior, and autism diagnosis.
Two years after entering intervention, the ESDM group on average improved 17.6 standard score
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points (1 SD:15 points) compared with 7.0 points in the comparison group relative to baseline
scores. The ESDM group maintained its rate of grow thin adaptive behavior compared with a
normative sample of typically developing children. In contrast, over the 2-year span, the
comparison group showed greater delays in adaptive behavior. Children who received ESDM also

Address correspondence to Geraldine Dawson, PhD, Autism Speaks, 4120 Bioinformatics Building, University of North Carolina,
Chapel Hill, North Carolina. gdawson@autismspeaks.org.
This trial has been registered at www.clinicaltrials.gov (identifier NCT00090415).
FINANCIAL DISCLOSURE: Sally Rogers and Geraldine Dawson are authors of Early Start Denver Model for Young Children with
Autism from which they receive royalties.
 Dawson et al. Page 2

were more likely to experience a change in diagnosis from autism to pervasive developmental
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disorder, not otherwise specified, than the comparison group.

CONCLUSIONS—This is the first randomized, controlled trial to demonstrate the efficacy of

a comprehensive developmental behavioral intervention for toddlers with ASD for improving
cognitive and adaptive behavior and reducing severity of ASD diagnosis. Results of this study
underscore the importance of early detection of and intervention in autism.

Keywords
autism; behavioral intervention; cognitive function; developmental outcomes; early intervention

Autism spectrum disorder (ASD) is characterized by impairments in social reciprocity and

communication, and stereotyped and repetitive behaviors, with onset during early childhood.
Intellectual disability is present in a large proportion of individuals.1 With a prevalence of 1
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per 150,2 autism costs the United States $35 billion per year.3 The lifetime per-capita
societal cost of autism is $3.2 million, with lost productivity and adult care among the
largest costs.4 Thus, early-intervention methods that can improve outcome for individuals
with ASD are of high importance.

The 1987 report by Lovaas5 of an early behavioral intervention that resulted in 49% of
children in the study being mainstreamed into regular classrooms and showing significant IQ
gains created a groundswell of interest among parents and professionals in early intervention
and raised questions about early plasticity in children with autism.6 Although subsequent
intervention studies, including a randomized, controlled trial,7 have documented
improvements in IQ for a subgroup of children, questions regarding the efficacy of early
intervention have remained. Many of the studies lacked methodologic rigor. Authors of a
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recent meta-analysis of the efficacy of early behavioral intervention argued that stronger
evidence that early behavioral intervention results in better outcomes than standard care is
still needed.8

Our study was a randomized, controlled trial of early intensive behavioral intervention for
young children with ASD that was funded by the National Institute of Mental Health (Dr
Dawson, principal investigator). It was hypothesized that the early intervention would result
in significant improvements in cognitive abilities of young children with ASD. The study
differed from previous ones in several ways. First, we maintained a high level of
methodologic rigor, including gold-standard diagnostic criteria, randomization,
comprehensive outcome measures conducted by naive examiners, high retention rates, and
measures of fidelity of implementation of a manualized intervention.
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Second, to our knowledge, our study is the first randomized, controlled trial of intervention
for toddlers with autism; all children were younger than 30 months at entry. Given the recent
recommendation by the American Academy of Pediatrics that 18-month-old children be
screened for ASD,9 it is imperative that the efficacy of early-intervention models appropriate
for toddlers with ASD be demonstrated.

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Third, the intervention, the Early Start Denver Model (ESDM),10 is a comprehensive early
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behavioral intervention for infants to preschool-aged children with ASD that integrates
applied behavior analysis (ABA) with developmental and relationship-based approaches.
The ESDM was designed to address the needs of toddlers with ASD as young as 12 months.
The intervention is provided in a toddler’s natural environment (the home) and is delivered
by trained therapists and parents. In our study, children received structured intervention at
high intensity, consistent with the National Research Council’s recommendation.11

PATIENTS AND METHODS

Study Procedures
Forty-eight children between 18 and 30 months of age diagnosed with autistic disorder or
pervasive developmental disorder (PDD), not otherwise specified (NOS), were randomly
assigned to 1 of 2 groups: (1) the ESDM group received yearly assessments, 20 hours/ week
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of the ESDM intervention from University of Washington clinicians, parent training, and
parent delivery for 5 or more hours/week of ESDM, in addition to whatever community
services the parents chose; and (2) the assess-and-monitor (A/M) group received yearly
assessments with intervention recommendations and referrals for intervention from
commonly available community providers in the greater Seattle region.

Children were evaluated by experienced examiners naive to intervention status at baseline

(preintervention), 1 year after onset of the intervention, and at either 2 years after onset of
the intervention or at 48 months of age, whichever yielded a longer time frame.

Participants
Participants were recruited through pediatric practices, Birth to Three centers, preschools,
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hospitals, and state and local autism organizations. Exclusion criteria included (1) a
neurodevelopmental disorder of known etiology (eg, fragile X syndrome), (2) significant
sensory or motor impairment, (3) major physical problems such as a chronic serious health
condition, (4) seizures at time of entry, (5) use of psychoactive medications, (6) history of a
serious head injury and/or neurologic disease, (7) alcohol or drug exposure during the
prenatal period, and (8) ratio IQ below 35 as measured by mean age equivalence score/
chronological age on the visual reception and fine motor subscales of the Mullen Scales of
Early Learning (MSEL).12 Children who developed seizures during the course of the study
were not excluded. Inclusion criteria included age below 30 months at entry, meeting criteria
for autistic disorder on the Toddler Autism Diagnostic Interview,13 meeting criteria for
autism or ASD on the Autism Diagnostic Observation Schedule,14 and a clinical diagnosis
based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)
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criteria15 using all available information, residing within 30 minutes of the University of
Washington, and willingness to participate in a ≥2-year intervention. At baseline, 18 children
in the A/M group and 21 in the ESDM group received a DSM-IV diagnosis of autistic
disorder. Six children in the A/M group and 3 in the ESDM group received a diagnosis of
PDD NOS. This difference was not significant (Fisher’s exact test, P = .231). The ethnicities
involved were Asian (12.5%), white (72.9%), Latino (12.5%), and multiracial (14.6%). The
male-to-female ratio reflected the expected ratio in ASD of 3.5:1.

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Retention rates were 100% (1-year) and 100% (2-year) for the ESDM group and 96% (1-
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year) and 88% (2-year) for the A/M group, which yielded a sample size of 24 in the ESDM
and 21 in the A/M group at outcome. Figure 1 shows the participant flowchart.

Measures
Autism Diagnostic Interview–Revised—The toddler version of the Autism
Diagnostic Interview–Revised13 is a semi-structured parent interview that assesses autism
symptoms across 3 domains: social relatedness; communication; and repetitive, restricted
behaviors.

Autism Diagnostic Observation Schedule—The Autism Diagnostic Observation

Schedule (ADOS), WPS version,14 is a semistructured standardized observation that
measures autism symptoms in social relatedness, communication, play, and repetitive
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behaviors. A standardized severity score based on codes within these domains can be
calculated to compare autism symptoms across modules.16

Mullen Scales of Early Learning (MSEL)—The MSEL12 are a standardized

developmental test for children from birth to 68 months of age. Four of the 5 subscales were
administered: fine motor, visual reception, expressive language, and receptive language. T
scores for subscales have a mean of 50 (SD: 10). The early-learning composite score is a
standard score with mean of 100 (SD: 15).

Vineland Adaptive Behavior Scales—The Vineland Adaptive Behavior Scales

(VABS)17 are a parent interview that assesses social, communication, motor, and daily living
skills. They provide age-equivalent and standard scores for several subscales, including
expressive and receptive language and social adaptive functioning.
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Repetitive Behavior Scale—The Repetitive Behavior Scale (RBS)18 is a parent

questionnaire that characterizes the severity of repetitive behaviors, yielding 6 subdomain
scores (eg, sameness, self-injurious behavior) and a total score.

Randomization
Participants were stratified into 2 groups on the basis of composite IQ at entry (<55 and 55)
and gender to ensure comparable IQ and gender ratios between groups. Within each of these
strata, randomization was conducted by using random permuted blocks of 4. The
intervention groups did not differ at baseline in severity of autism symptoms based on
ADOS scores, chronological age, IQ, gender, or adaptive behaviors (see Table 1).
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Intervention Groups
ESDM Group—The ESDM group was provided with intervention by trained therapists
for 2-hour sessions, twice per day, 5 days/ week, for 2 years. A detailed intervention manual
and curriculum were used.19 One or both parents were provided with parent training from
the primary therapist during semimonthly meetings, during which the principles and specific
techniques of ESDM were taught. Parents were asked to use ESDM strategies during daily
activities and to keep track of the number of hours during which they used these strategies.

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ESDM uses teaching strategies that involve interpersonal exchange and positive affect,
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shared engagement with real-life materials and activities, adult responsivity and sensitivity
to child cues, and focus on verbal and nonverbal communication, based on a
developmentally informed curriculum that addresses all developmental domains. Teaching
strategies are consistent with the principles of ABA, such as the use of operant conditioning,
shaping, and chaining. Each child’s plan is individualized. There is a strong parent-family
role responsive to each family’s unique characteristics. Parents are taught the basic ESDM
strategies and asked to use them during everyday activities such as feeding, bath time, and
play. Parents chose teaching objectives from the curriculum that they viewed as high priority.

Intervention programs were supervised by a graduate-level, trained lead therapist who had a
minimum of 5 years’ experience providing early intervention to young children with autism,
with ongoing consultation from a clinical psychologist, speech-language pathologist, and
developmental behavioral pediatrician. An occupational therapist provided consultation as
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needed. Intervention objectives and strategies were reviewed, and the intervention was
observed at least biweekly by the lead therapist and every 3 months by the speech-language
pathologist. Intervention was delivered by therapists who typically held a baccalaureate
degree, received 2 months of training by the lead therapist, and met weekly with the lead
therapist. Therapists were trained to competence, defined as completing course-work,
passing tests, mastering the intervention, demonstrating fidelity of 85% of maximum scores
on the fidelity instrument, and maintaining ongoing fidelity.20

ESDM intervention hours were systematically recorded. Although 20 therapist-delivered

intervention hours per week were made available, the actual mean was 15.2 hours (SD: 1.4)
because of illnesses, vacations, and so on. Parents reported spending an average of 16.3
hours/week (SD: 6.2) using ESDM strategies. The ESDM group reported an average of 5.2
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hours/week (SD: 2.1) in other therapies (eg, speech therapy, developmental preschool) over
the study enrollment period. Other therapies were documented by using an intervention
history interview administered every 6 months.

A/M Group—Children who were randomly assigned to the A/M group received
comprehensive diagnostic evaluations, intervention recommendations, and community
referrals at baseline and again at each of the 2 follow-up assessments. Families were given
resource manuals and reading materials at baseline and twice yearly throughout the study.
The A/M group reported an average of 9.1 hours of individual therapy and an average of 9.3
hours/week of group interventions (eg, developmental pre-school) across the 2-year period
during which the intervention study was conducted. In the greater Seattle area, there are a
number of Birth to Three centers that provide interventions, speech and language therapy,
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and occupational therapy. Developmental preschool programs vary but typically include
special education and related services. There are a number of private ABA providers in the
community.

Data Analysis
The effect of ESDM intervention was assessed by using repeated-measures analysis of
variance, with a priori contrasts that compared baseline scores with 1- and 2-year outcome

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scores. The primary outcome measures were the MSEL composite standard score and the
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VABS composite standard score. Secondary outcome measures were the ADOS severity
score,16 the RBS,18 MSEL, and VABS subscale scores, and changes in diagnostic status
(autistic disorder, PDD NOS, and no diagnosis).

RESULTS
No serious adverse effects related to the intervention were reported during the 2-year period.

1-Year Outcome
Table 2 displays statistics for 1- and 2-year outcomes, change scores relative to baseline, and
group comparisons for primary and secondary measures. Significant intervention effects
were found for cognitive ability after 1 year on the MSEL composite standard scores. The
ESDM group demonstrated an average IQ increase of 15.4 points (>1 SD) compared with an
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increase of 4.4 points in the A/M group. The visual reception subscale was the only
individual subscale on the MSEL on which the groups significantly differed at the 1-year
outcome. The ESDM group gained 5.6 T-score points, whereas the A/M group declined 1.7
points. The ESDM group improved 17.8 points on receptive language compared with a 9.8-
point improvement in the A/M group, a difference that fell just short of statistical
significance.

As a whole, children gained raw score points in the daily living skills subscale of the VABS;
however, progress was much slower in relation to the VABS normative sample between
baseline and 1 year. The groups did not differ in terms of adaptive behavior, measured by the
VABS composite standard score, after 1 year (the ESDM group showed a 3.8-point decline,
and the A/M group showed a 6.3-point decline). The groups did not differ in terms of their
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ADOS severity scores or RBS total score after 1 year of intervention.

2-Year Outcome
Two years after the baseline assessment, the ESDM group showed significantly improved
cognitive ability, measured by MSEL composite standard scores, which increased 17.6
points compared with 7.0 points in the A/M group. The bulk of this change seems to have
been a result of receptive and expressive language, which showed increases of 18.9 and 12.1
points, respectively, for the ESDM group, whereas the A/M group improved 10.2 and 4.0
points, respectively.

The ESDM and A/M groups significantly differed in terms of their adaptive behavior as
measured by the VABS composite standard scores at the 2-year outcome (see Fig 2). The
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ESDM group showed similar standard scores at the 1- and 2-year outcomes, indicating a
steady rate of development, whereas the A/M group, on average, showed an 11.2-point
average decline. Thus, the A/M group’s delays in overall adaptive behavior became greater
when compared with the normative sample. The A/M group showed average declines in
standard scores that were twice as great as those in the ESDM group in the domains of
socialization, daily living skills, and motor skills. The groups did not differ in terms of their
ADOS severity scores or RBS total score after 2 years of intervention.

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Diagnosis
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At baseline, the diagnoses in each group were not significantly different (Fisher’s exact test,
P =.461) and were distributed as follows: ESDM, 21 with autistic disorder and 3 with PDD
NOS; A/M, 18 with autistic disorder and 6 with PDD NOS. At the 2-year outcome, 15
(62.5%) children in the ESDM group had the same diagnosis (14 with autistic disorder, 1
with PDD NOS) and 15 (71.4%) children in the A/M group had the same diagnosis (all 15
with autistic disorder). Diagnosis improved (baseline autistic disorder to PDD NOS at year
2) for 7 (29.2%) children in the ESDM group but for only 1 (4.8%) child in the A/M group.
However, the diagnosis changed from PDD NOS at baseline to autistic disorder at year 2 for
2 (8.3%) children in the ESDM group and 5 (23.8%) children in the A/M group. Thus,
children who received ESDM were significantly more likely to have improved diagnostic
status at the 2-year outcome compared with children in the A/M group, as assessed by using
Fisher’s exact test 2 (intervention groups) × 2 (improved versus worsened diagnosis)
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contingency table (P = .041). Fisher’s exact test for the 2 (intervention groups) × 3
(diagnostic change: no change versus improved versus worsened diagnosis) contingency
table was just short of significance (P = .060).

DISCUSSION
Recommendations by the American Academy of Pediatrics9 that all children be screened for
autism at 18 months of age oblige the development of interventions that are appropriate for
toddlers with ASD. To our knowledge, this study is the first to demonstrate the efficacy of an
intensive intervention designed for toddlers with ASD as young as 12 months of age. After 2
years of intervention, children provided with the ESDM19 showed significant improvements
in IQ, adaptive behavior, and diagnostic status compared with children who received
community interventions. Consistent evidence of improvement in communicative abilities in
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the ESDM group was found, as demonstrated by gains in receptive and expressive language
scores on the MSEL subscales and the VABS communication subscale. Significant
improvement for the ESDM group was found for overall adaptive behavior, communication,
daily living skills, and motor skills. Specifically, the ESDM group, although still
significantly delayed in adaptive behavior, was able to keep pace with the rate of change of
the VABS normative sample, whereas the community-based intervention group continued to
fall farther behind in adaptive behavior. Given the importance of adaptive behavior for
everyday functioning at home and school, the fact that the ESDM group did not continue to
fall farther behind is likely to affect ability to function in less-restrictive environments. This
demonstrates that the ESDM intervention accelerates overall development and is
generalizing to everyday life. Whereas 71% of the children in the group that received
community-based intervention retained their diagnosis of autistic disorder over the 2-year
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period, only 56% of children in the ESDM group did so. The diagnosis of 7 children (30%)
in the ESDM group changed from autistic disorder to PDD NOS, whereas this only occurred
for 1 child (5%) in the community-intervention group. These diagnostic assessments were
conducted by experienced clinicians who were naive with respect to intervention-group
status. However, this change in diagnostic severity was not reflected in significant
differences in the ADOS severity scores. This lack of correspondence between measures is
difficult to interpret, because the child’s performance in the ADOS contributes to clinical

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diagnosis. However, other behaviors, including parental report, also contribute to overall
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clinical diagnosis. The repetitive-behavior scores also did not change over time in either
group.

CONCLUSIONS
The outcomes of this study, which involve an increase in IQ scores of 17 points (>1 SD) and
significant gains in language and adaptive behavior, compare favorably with other controlled
studies of intensive early intervention (eg, Smith et al [2000],7 which delivered discrete trial
intervention for >2 years for 25–40 hours/week). The group differences reported from our
study are larger than those produced by other comparative trials of developmental behavioral
approaches, which were conducted for briefer periods of time and with fewer hours of
delivery per week.21,22 Whether the children will sustain their gains over a longer term is an
important question that will require follow-up study.
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The results of this study suggest that the ESDM model,19 an intervention approach that uses
teaching strategies of ABA that are delivered within an affectively rich, relationship-focused
context, can be effective for improving outcomes of young children with autism. Parents’
use of these strategies at home during their daily activities likely was an important ingredient
of its success.

Acknowledgments
This study was supported by National Institute of Mental Health grant U54MH066399 (to Dr Dawson).

We acknowledge the contributions of the parents and children who took part in this study and the support and effort
of numerous undergraduate and graduate students and staff who are part of the University of Washington Autism
Center.
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ABBREVIATIONS
ASD autism spectrum disorder

ESDM Early Start Denver Model

ABA applied behavior analysis

A/M assess and monitor

PDD pervasive developmental disorder

NOS not otherwise specified

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MSEL Mullen Scales of Early Learning

ADOS Autism Diagnostic Observation Schedule

VABS Vineland Adaptive Behavior Scales

RBS Repetitive Behavior Scale

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References
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1. Baird G, Simonoff E, Pickles A, et al. Prevalence of disorders of the autism spectrum in a

population cohort of children in South Thames: the Special Needs and Autism Project (SNAP).
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2. Yeargin-Allsopp M, Rice C, Karapurkar T, Doemberg N, Coyle C, Murphy C. Prevalence of autism
in a U.S. metropolitan area. JAMA. 2003; 289(1):49–55. [PubMed: 12503976]
3. Ganz, ML. The costs of autism. In: Molden, SO.; Rubenstein, JLR., editors. Understanding Autism:
From Basic Neuroscience to Treatment. Boca Raton, FL: Taylor and Francis Group; 2006.
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Med. 2007; 161(4):343–349. [PubMed: 17404130]
5. Lovaas OI. Behavioral treatment and normal educational and intellectual functioning in young
autistic children. J Consult Clin Psychol. 1987; 55(1):3–9. [PubMed: 3571656]
6. Dawson G. Early behavioral intervention, brain plasticity, and the prevention of autism spectrum
disorder. Dev Psychopathol. 2008; 20(3):775–803. [PubMed: 18606031]
7. Smith T, Groen AD, Wynn JW. Randomized trial of intensive early intervention for children with
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pervasive developmental disorder. Am J Ment Retard. 2000; 105(4):269–285. [PubMed: 10934569]

8. Spreckley M, Boyd R. Efficacy of applied behavioral intervention in preschool children with autism
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Identification and evaluation of children with autism spectrum disorders. Pediatrics. 2007; 120(5):
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10. Smith, M.; Rogers, S.; Dawson, G. The Early Start Denver Model: a comprehensive early
intervention approach for toddlers with autism. In: Handleman, JS.; Harris, SL., editors. Pre-
school Education Programs for Children With Autism. 3. Austin, TX: Pro-Ed Corporation, Inc;
2008. p. 65-101.
11. National Research Council, Division of Behavioral and Social Sciences Education. Educating
Children With Autism. Washington, DC: National Academy Press; 2001.
12. Mullen, EM. Mullen Scales of Early Learning: AGS Edition. Circle Pines, MN: American
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Guidance Service; 1995.

13. Lord C, Rutter M, Le Couteur A. Autism Diagnostic Interview-Revised: a revised version of a
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J Autism Dev Disord. 1994; 24(5):659–685. [PubMed: 7814313]
14. Lord, C.; Rutter, M.; DiLavore, PC.; Risi, S. Autism Diagnostic Observation Schedule. Los
Angeles, CA: Western Psychological Services; 1999.
15. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4.
Washington, DC: American Psychiatric Association; 1994.
16. Gotham K, Pickles A, Lord C. Standardizing ADOS scores for a measure of severity in autism
spectrum disorders. J Autism Dev Disord. 2009; 39(5):693–705. [PubMed: 19082876]
17. Sparrow, S.; Balla, D.; Cicchetti, D. Vineland Adaptive Behavior Scales: Interview Edition. Circle
Pines, MN: American Guidance Service; 1984.
18. Bodfish, JW.; Symons, FJ.; Lewis, MH. The Repetitive Behavior Scale: A Test Manual.
Morganton, NC: Western Carolina Center Research Reports; 1998.
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19. Rogers, SJ.; Dawson, G. Early Start Denver Model for Young Children with Autism. New York,
NY: Guilford Press; 2009.
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rehabilitation. Ment Health Serv Res. 2000; 2(2):75–87. [PubMed: 11256719]
21. Jocelyn LJ, Casiro OG, Beattie D, Bow J, Kneisz J. Treatment of children with autism: a
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22. Aldred C, Green J, Adams C. A new social communication intervention for children with autism:
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2004; 45(8):1420–1430. [PubMed: 15482502]

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WHAT’S KNOWN ON THIS SUBJECT

Previous studies on the efficacy of early behavioral intervention for improving outcomes
for preschool-aged children with autism have yielded promising results. However, no
randomized clinical trials of early developmental behavioral intervention designed for
toddlers with autism have been conducted to date.

WHAT THIS STUDY ADDS

This study assessed the efficacy of the Early Start Denver Model, a comprehensive
developmental behavioral intervention, for improving outcomes of toddlers with ASD.
The intervention, which was initiated when children were less than 2½ years, resulted in
significant improvements in IQ, language, adaptive behavior, and autism diagnosis.
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FIGURE 1.
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Participant flowchart.
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FIGURE 2.
Mean scores on the MSEL (left) and the VABS composite (right) for children in the ESDM
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and A/M groups 1 and 2 years after entering study. Error bars indicate ±1 SD.
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TABLE 1

Baseline Measures for ESDM and A/M Groups

A/M Group ESDM Group F MS P

Dawson et al.

Mean SD N Mean SD N
Age at study entry, mo 23.1 3.9 24 23.9 4.0 24 0.48 7.52 .490
MSEL

Early-learning compositea 59.4 8.6 24 61.0 9.2 24 0.40 31.69 .530

Receptive languageb 21.2 3.8 24 21.1 4.7 24 0.01 0.19 .920

Expressive languageb 26.0 8.6 24 24.5 7.2 24 0.48 30.08 .492

Visual receptionb 30.8 8.9 24 33.2 11.0 24 0.70 70.08 .406

Fine motorb 30.6 10.7 24 33.9 11.9 24 1.02 130.02 .318

VABS

Adaptive behavior compositea 69.9 7.3 24 69.5 5.7 24 0.04 1.69 .844

Communicationa 69.6 7.3 24 68.4 7.6 24 0.32 17.52 .577

Socializationa 72.4 9.4 24 73.8 7.7 24 0.29 21.33 .594

Daily living skillsa 86.8 10.0 24 87.3 11.4 24 0.03 3.52 .381

Motor skillsa 72.5 6.5 24 70.9 6.2 24 0.78 31.69 .862

ADOS severity score 6.9 1.7 24 7.2 1.7 24 0.35 1.02 .557
RBS total 21.5 19.2 24 15.2 10.8 24 1.93 468.75 .171

No significant differences among baseline measures were found (P > .10 on all measures).

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a
Standard score (mean: 100 [SD: 15]).
b
T score (mean: 50 [SD: 10]).
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TABLE 2

Child Outcomes After 1 and 2 Years of Study Participation

1-y Outcome 2-y Outcome

Dawson et al.

A/M (N =23) ESDM (N =24) A/M (N =21) ESDM (N =24) Group × Time (Baseline vs 1-y) Group × Time (Baseline vs 2-y)

Mean SD Δ Mean SD Δ Mean SD Δ Mean SD Δ F MS P F MS P

Chronological age, mo 38.1 3.8 15.3 38.8 4.4 14.9 52.1 4.3 29.3 52.4 3.4 28.5 0.95 2.18 .334 1.27 6.91 .266
MSEL
Early-learning composite 64.0 13.8 4.4 76.4 23.4 15.4 66.3 15.3 7.0 78.6 24.2 17.6 5.99 1416.90 .018 4.31 1264.38 .044
Receptive language 31.1 11.1 9.8 38.9 15.4 17.8 31.5 10.6 10.2 40.0 16.3 18.9 4.00 745.21 .051 4.14 843.56 .048
Expressive language 33.0 11.5 6.7 36.1 14.2 11.6 30.0 9.2 4.0 36.6 13.6 12.1 1.99 290.43 .165 4.88 748.07 .033
Visual reception 29.0 10.7 −1.7 38.8 16.4 5.6 34.5 13.0 4.5 41.0 17.9 7.8 4.22 621.97 .046 0.63 126.23 .433
Fine motor 26.1 8.6 −5.0 32.7 11.7 −1.3 28.5 9.5 −2.8 33.5 12.2 −0.4 1.32 161.35 .256 0.46 63.81 .503
VABS 63.7 8.8 −6.3 65.7 9.8 −3.8 59.1 8.8 −11.2 68.7 15.9 −0.8 0.85 71.61 .360 7.05 1181.82 .011
Communication 71.0 13.0 1.2 73.5 11.7 5.0 69.4 15.8 −0.7 82.1 21.8 13.7 1.38 175.69 .246 6.38 2300.98 .015
Socialization 68.9 12.1 −3.5 70.0 9.9 −3.8 63.1 9.3 −8.9 69.2 11.6 −4.6 0.01 1.15 .934 1.29 204.57 .263
Daily living skills 65.3 7.1 −7.4 65.6 8.6 −5.3 58.0 8.1 −14.5 64.7 12.4 −6.2 0.89 51.78 .350 6.73 773.34 .013
Motor skills 70.7 12.2 −15.9 75.1 14.4 −12.2 64.1 12.3 −23.1 77.4 19.8 −9.9 0.99 157.43 .326 7.40 1881.65 .009
ADOS severity score 7.3 2.1 0.4 6.5 1.5 −0.7 7.3 1.8 0.3 7.0 1.9 −0.2 3.38 13.15 .072 0.66 3.29 .422
RBS total 23.3 17.5 1.0 15.5 12.3 0.9 22.0 16.3 −0.6 16.7 13.1 2.5 0.001 0.19 .976 0.37 92.50 .545

Δ indicates mean change from baseline.

Pediatrics. Author manuscript; available in PMC 2016 July 19.

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