Dawson, G., Rogers, S., Munson, J., Smith, M., Winter, J., Greenson, J.,... Varley, J. (2010). Randomized, controlled trial of an intervention for toddlers with autism: The Early Start Denver Model. Pediatrics, 125(1), e17 e23. https://doi.org/10.1542/peds.2009-0958 CLINICAL BOTTOM LINE Early Intervention for Children With Autism Efficacious, evidence-based early intervention for children with autism spectrum disorders (ASD) is of the utmost importance, given the high prevalence and reliable early diagnosis. Starting therapeutic intervention immediately after diagnosis increases the likelihood of positive outcomes and leads to increased functional capabilities for daily activities in the home and school setting. Early interventions are moving toward incorporating caregivers in the child s natural environment, to increase generalization of learned skills and capitalize on the significant amount of time caregivers spend with their children. The current randomized controlled trial compared the Early Start Denver Model (ESDM) with an assess-and-monitor (A/M) control group to determine the effects on cognitive ability, adaptive behavior, and diagnostic status among 45 children (18 to 30 months) with autistic disorder or pervasive developmental disorder not otherwise specified (PDD NOS). ESDM, delivered about 20 hours/week for 2 years, is a parent- and therapist-delivered therapy with elements of development domains, applied behavior analysis (ABA) therapy, and relationship building incorporated into daily activities. The A/M group, monitored for 2 years, received diagnostic evaluations, community provider referrals, intervention recommendations, and reading material and resource provisions. After 2 years, children in the ESDM group showed significant improvements in cognitive ability, adaptive behavior (overall adaptive behavior, communication, daily living skills, and motor skills), and diagnostic status compared with the A/M group. Diagnostic severity and repetitive-behavior scores did not differ between treatment groups. Implications for Occupational Therapy Improved cognitive abilities and adaptive behavior support children s development and overall participation in multiple contexts. Occupational therapists can use evidence from this study to support the implementation of the ESDM with young children with autism. In particular, this study provides evidence for use of a therapist- and parent-led program that is implemented in 1
the home. Therapeutic intervention in the child s natural environment increases the likelihood that the child will implement skills learned during therapeutic sessions into daily life activities. Including parents as therapeutic agents also increases the likelihood that children will generalize skills into their daily activities, because therapy is integrated into their natural daily routine with their caregiver. Occupational therapists working in early-intervention programs in the home can implement the ESDM, including parent training, to attain improved cognitive and adaptive behavior outcomes for young children with autism. Occupational therapists training in holistic evaluation can ensure that delivery of the ESDM model is individualized to each family unit. In addition, occupational therapy practitioners can assist other therapists who may be involved in service delivery (e.g., ABA therapists) in problem solving any challenges that may arise. In particular, occupational therapists can tailor interventions to support developmentally appropriate child occupations. RESEARCH OBJECTIVE(S) Evaluate the efficacy of an intensive developmental-behavioral therapy intervention, compared with standard care, for improving outcomes among toddlers with ASD DESIGN TYPE AND LEVEL OF EVIDENCE Level I: Randomized controlled trial PARTICIPANT SELECTION How were participants recruited and selected to participate? Participants were recruited through pediatric practices, Birth to Three centers, preschools, hospitals, and state and local autism organizations. Inclusion criteria: Inclusion criteria included child s age less than 30 months at entry, residence within 30 minutes of the University of Washington, and willingness to participate in a 2-year (or longer) intervention. Children were also required to meet criteria for autistic disorder on the Toddler Autism Diagnostic Interview; meet criteria for autism or autism spectrum disorder on the Autism Diagnostic Observation Schedule; and receive a clinical diagnosis based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria, given all available information. 2
Exclusion criteria: Exclusion criteria included a neurodevelopmental disorder of known etiology; significant sensory or motor impairment; major physical problems, such as a chronic, serious health condition; seizures at time of entry; use of psychoactive medications; history of a serious head injury and/or neurologic disease; alcohol or drug exposure during the prenatal period; and 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. Children who developed seizures during the course of the study were not excluded. PARTICIPANT CHARACTERISTICS N= 48 #/ % Male: Male-to-female ratio was 3.5:1. Specific numbers were not reported. #/ % Female: Male-to-female ratio was 3.5:1. Specific numbers were not reported. Ethnicity: Asian (12.5%) Disease/disability diagnosis: White (72.9%) Latino (12.5%) Multiracial (14.6%) Autism, autistic disorder, autism spectrum disorder, or PDD NOS INTERVENTION AND CONTROL GROUPS Group 1: ESDM group Brief description of the intervention Participants in the ESDM group received therapy from therapists and parents around topics including interpersonal exchange and positive affect, shared engagement with real-life materials and activities, adult responsivity and sensitivity to child cues, and focus on verbal and nonverbal communication. The ESDM therapy addresses all developmental domains and includes aspects of ABA therapy, such as operant conditioning, chaining, and shaping. Therapy sessions were highly individualized to each family; parents 3
were allowed to choose the curriculum objectives to focus on and how best to include them in daily family routines, such as bathing, play, and feeding. Some participants chose to receive additional therapy services during this study. How many participants in the group? Where did the intervention take place? Who delivered? How often? For how long? A total of 24 participants entered the study, with 100% retention at the end of the intervention. Of the total participants, 21 had a diagnosis of autistic disorder, and 3 had a diagnosis of PDD NOS. In the child s home The intervention was primarily carried out by therapists with a baccalaureate degree who received 2 months of training by the lead therapist, consisting of completing coursework, passing tests, mastering the intervention, demonstrating fidelity of 85% of maximum scores on the fidelity of the instrument, and maintaining ongoing fidelity. Therapists met weekly with the lead therapist, were observed by lead therapists at least biweekly, and were observed by the speech language pathologist every 3 months. Therapists were provided with a detailed intervention manual and curriculum. Lead therapists were graduate level and had a minimum of 5 years experience providing early intervention to young children with autism. Ongoing consultation was received from a clinical psychologist, speech language pathologist, and developmental behavioral pediatrician. An occupational therapist was consulted as needed. Participants attended 2-hour sessions, twice per day, 5 days per week. Actual mean therapist intervention hours were 15.2 hours (SD = 1.4) because of vacations, illness, and so forth. Parents reported a mean 16.3 hours per week (SD = 6.2) using ESDM strategies and a mean of 5.2 hours per week (SD = 2.1) that their child spent in other therapies. The second time point was 2 years after onset or 48 months of age, whichever yielded a longer time frame. Group 2: A/M group Brief description of the intervention Participants received comprehensive diagnostic evaluations; referrals to community service providers for community-based interventions; and recommendations for interventions at baseline, after 1 year, and after 2 years. Resource manuals and reading materials were provided to families at baseline and every 6 months after for the duration of the study. 4
How many participants in the group? Where did the intervention take place? Who delivered? How often? For how long? A total of 24 participants entered the study, with 1 lost to follow-up at Time 1 (after 1 year) and 2 more lost to follow-up at Time 2 (after 2 years). In all, 21 participants completed the study. Eighteen participants had a diagnosis of autistic disorder, and 6 had a diagnosis of PDD NOS. Greater Seattle region therapy clinics, developmental preschools, the child s home, and Birth to Three centers Birth to Three centers, speech and language therapists, occupational therapists, developmental preschools, and private ABA providers Parents reported an average of 9.1 hours of individual therapy and an average of 9.3 hours per week of group interventions. The second time point was 2 years after onset or 48 months of age, whichever yielded a longer time frame. INTERVENTION BIASES Contamination: YES NO Co-intervention: Timing of intervention: Site of intervention: Although not specifically reported, contamination was unlikely to have occurred in this study. The intervention, ESDM, was highly individualized and occurred in the home environment, so it is unlikely that children in the control group were exposed to the intervention. It is possible, however, that families had contact in services outside of the study (speech therapy, developmental preschools, support groups, etc.), given their close geographic proximity. Although not specifically addressed, cointervention could have affected the results of this study. Participants in both treatment groups were receiving outside therapies that could have influenced their outcomes. Although not specifically reported, maturation effects are possible given the lengthy (2 years) duration of the intervention. Intervention-group therapy sessions took place in the home, which might have increased generalizability of learned skills. The authors did not report where children in the control group received therapy intervention. Use of different therapists to provide intervention: 5
Although multiple therapists were used in both the intervention and the control group, the researchers took great care to extensively train therapists. In addition, all therapists participated in biweekly supervision by the lead therapist and supervision by the speech language pathologist at least every 3 months. A detailed intervention manual and curriculum were used. Baseline equality: YES Intervention and control groups did not differ at baseline in severity of NO autistic symptoms, on the basis of Autism Diagnostic Observation Schedule scores, chronological age, IQ, gender, or adaptive behaviors. The difference between the number of participants with autistic disorder and with PDD NOS in each treatment condition was not significant (p =.231). MEASURES AND OUTCOMES Measure 1: Autism Diagnostic Observation Schedule Name/type of measure used: What outcome is measured? Is the measure reliable as reported in the article? Is the measure valid as reported in the article? When is the measure used? Autism Diagnostic Observation Schedule (ADOS), WPS version Autism symptoms in social relatedness, communication, play, and repetitive behaviors YES Not Reported YES Not Reported Baseline, Time 1 (1 year), and Time 2 (2 years or 48 months of age, whichever yielded a longer time frame) Measure 2: Mullen Scales of Early Learning Name/type of measure used: What outcome is measured? Is the measure reliable as reported in the article? Is the measure valid as reported in the article? When is the measure used? Mullen Scales of Early Learning (MSEL) Four of five subscales were used to measure fine motor skills, visual reception, expressive language, and receptive language. Additionally, an early-learning composite score was calculated. YES Not Reported YES Not Reported Baseline, Time 1 (1 year), and Time 2 (2 years or 48 months of age, whichever yielded a longer time frame) 6
Measure 3: Vineland Adaptive Behavior Scales Name/type of measure used: What outcome is measured? Is the measure reliable (as reported in the article)? Is the measure valid (as reported in the article)? When is the measure used? Measure 4: Repetitive Behavior Scale Name/type of measure used: What outcome is measured? Is the measure reliable (as reported in the article)? Is the measure valid (as reported in the article)? When is the measure used? Vineland Adaptive Behavior Scales (VABS) Social, communication, motor, and daily living skills YES Not Reported X YES Not Reported X Baseline, Time 1 (1 year), and Time 2 (2 years or 48 months of age, whichever yielded a longer time frame) Repetitive Behavior Scale (RBS) Repetitive behaviors, with six subdomain scores (e.g., sameness, selfinjurious behavior) and a total score YES Not Reported X YES Not Reported X Baseline, Time 1 (1 year), and Time 2 (2 years or 48 months of age, whichever yielded a longer time frame) Measure 5: Autism Diagnostic Interview Revised Name/type of measure used: What outcome is measured? Is the measure reliable (as reported in the article)? Is the measure valid (as reported in the article)? When is the measure used? Autism Diagnostic Interview Revised, Toddler Version Autism symptoms in social relatedness; communication; and repetitive, restricted behaviors YES Not Reported X YES Not Reported X To determine inclusion in the study 7
MEASUREMENT BIASES Were the evaluators blind to treatment status? Was there recall or memory bias? Participants were evaluated by examiners who were blinded to intervention status at each time point. Memory bias was not specifically reported; however, two of the measures (the VABS and the RBS) rely on parent report and were measured at three time points, which created a possibility for recall bias to occur. Other measurement biases: (List and explain) RESULTS List key findings based on study objectives: One-Year Outcome The ESDM group had significantly greater cognitive ability (measured by MSEL composite standard scores) after 1 year (p =.018). ESDM participants only performed significantly better than the A/M comparison group on one subscale of the MSEL, however: the Visual Reception subscale (p =.046). After 1 year, groups did not differ in terms of adaptive behavior (VABS composite standard score), ADOS severity scores, or RBS total score. Two-Year Outcome The ESDM group had significantly improved cognitive ability (measured by MSEL composite standard scores) after 1 year, compared with the A/M group (p =.018). This overall improvement was in large part due to improvement on the Receptive Language (p =.048) and Expressive Language (p =.033) subscales by the ESDM group. The ESDM group showed signs of steady rates of development (significantly delayed, but at the same pace as the normative sample) of adaptive behavior at Time 1 and Time 2 (as measured by the VABS composite standard scores), compared with the A/M group, which showed a much greater decline in adaptive behavior each year (p =.011). In three domains of the VABS (socialization, daily living skills, and motor skills), participants in the A/M group showed average standard score declines that were twice as great as those in the ESDM group. The treatment groups only showed significant differences for the domains of communication (p =.015), daily living skills (p =.013), and motor skills (p =.009), however. After 2 years, groups did not differ in terms of ADOS severity scores or RBS total score. Diagnosis No significant diagnosis differences existed between groups at baseline (Fisher s exact test, P =.461). After 2 years, 62.5% (n = 15) of participants in the ESDM group had the same diagnosis as at baseline, compared with 71.4% (n = 15) of participants in the A/M group. Diagnosis improved (autistic disorder at baseline to PDD NOS at Time 2) for 29.2% (n = 7) of participants 8
in the ESDM group and 4.8% (n = 1) in the A/M group. Diagnosis changed from PDD NOS at baseline to autistic disorder at Time 2 for 8.3% (n = 2) participants in the ESDM group and 23.8% (n = 5) in the A/M group. Participants in the ESDM group were significantly more likely to have improved diagnostic status at Time 2 compared with participants in the A/M group (p =.041). Was this study adequately powered (large enough to show a difference)? This study seemed to be adequately powered for the analysis performed, given that statistical significance was found on many of the primary outcome variables. The authors did not report doing a power analysis prior to study design and recruitment, however. Were the analysis methods appropriate? The researchers used repeated-measures analysis of variance, with a priori contrast that compared baseline scores with 1- and 2-year outcome scores. Repeated-measures analysis of variance was appropriate for this dataset because of the presence of more than two matched samples for each condition. Additionally, the researchers used Fisher s exact test to determine differences between treatment groups in number of participants with each diagnosis at baseline and diagnostic status changes at Time 2. Fisher s exact test was appropriate for this dataset because of the presence of two categorical variables (ESDM or A/M; diagnosis or no diagnosis). Were statistics appropriately reported (in written or table format)? All statistics were appropriately reported at multiple time points in the narrative and in tables. Was participant dropout less than 20% in total sample and balanced between groups? YES NO Participant dropout was 0% in the ESDM group and 12% in the A/M group (loss of 3 participants at follow-up). The researchers highlighted the high retention rates as a strength of the study, given that it took place over more than 2 years. What are the overall study limitations? This study did not exclude participants who were receiving therapies outside of the intervention, which increases the risk that cointervention affected the outcomes of children in both groups. Maturation effects must be also be considered as having possibly affected outcomes, because the study took place over longer than 2 years. In addition, the researchers did not complete longterm follow-up postintervention to determine whether children maintained their gains compared with the A/M group. Finally, demographic information reported is limited. If present, demographic information would have informed readers of the applicability of ESDM to wider populations. 9
CONCLUSIONS State the authors conclusions related to the research objectives. Using a randomized controlled design, the researchers found that the ESDM, compared with an A/M comparison group, was effective for improving children s IQ, adaptive behavior, and autism diagnosis over the 2-year intervention. Interventionists and parents used ABA teaching strategies in a relationship-focused context. The central role of parents in the intervention allowed the implementation of strategies at home in daily activities, which was considered an essential component of the successful intervention. This work is based on the evidence-based literature review completed by Sarah Hope, OTS, and Karla Ausderau, PhD, OTR/L, faculty advisor, University of Wisconsin, Madison. CAP Worksheet adapted from Critical Review Form Quantitative Studies. Copyright 1998, by M. Law, D. Stewart, N. Pollack, L. Letts, J. Bosch, & M. Westmorland, McMaster University. Used with permission. For personal or educational use only. All other uses require permission from AOTA. Contact: www.copyright.com 10