Journal of Child Psychology and Psychiatry **:* (2014), pp **–**
doi:10.1111/jcpp.12354
A randomized controlled trial of Pivotal Response Treatment Group for parents of children with autism Antonio Y. Hardan,1 Grace W. Gengoux,1 Kari L. Berquist,1 Robin A. Libove,1 Christina M. Ardel,1 Jennifer Phillips,1 Thomas W. Frazier,2 and Mendy B. Minjarez3 1
Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA; 2Center for Autism, Cleveland Clinic, Cleveland, OH; 3Seattle Children’s Hospital/Seattle Children’s Research Institute, Seattle, WA, USA
Background: With rates of autism diagnosis continuing to rise, there is an urgent need for effective and efficient service delivery models. Pivotal Response Treatment (PRT) is considered an established treatment for autism spectrum disorder (ASD); however, there have been few well-controlled studies with adequate sample size. The aim of this study was to conduct a randomized controlled trial to evaluate PRT parent training group (PRTG) for targeting language deficits in young children with ASD. Methods: Fifty-three children with autism and significant language delay between 2 and 6 years old were randomized to PRTG (N = 27) or psychoeducation group (PEG; N = 26) for 12 weeks. The PRTG taught parents behavioral techniques to facilitate language development. The PEG taught general information about ASD (clinical trial NCT01881750; http://www.clinicaltrials.gov). Results: Analysis of child utterances during the structured laboratory observation (primary outcome) indicated that, compared with children in the PEG, children in the PRTG demonstrated greater improvement in frequency of utterances (F(2, 43) = 3.53, p = .038, d = 0.42). Results indicated that parents were able to learn PRT in a group format, as the majority of parents in the PRTG (84%) met fidelity of implementation criteria after 12 weeks. Children also demonstrated greater improvement in adaptive communication skills (Vineland-II) following PRTG and baseline Mullen visual reception scores predicted treatment response to PRTG. Conclusions: This is the first randomized controlled trial of group-delivered PRT and one of the largest experimental investigations of the PRT model to date. The findings suggest that specific instruction in PRT results in greater skill acquisition for both parents and children, especially in functional and adaptive communication skills. Further research in PRT is warranted to replicate the observed results and address other core ASD symptoms. Keywords: Language deficits, treatment fidelity, group parent training, social communication, naturalistic developmental behavior intervention.
Introduction Autism spectrum disorder (ASD) is characterized by social communication deficits and repetitive behaviors (American Psychiatric Association, 2013). With greater than 1% of children carrying an ASD diagnosis (Center for Disease Control, 2014), the development of empirically supported treatments for ASD is a critical priority. While early intervention improves cognitive, language, and adaptive skills for many children (Dawson & Burner, 2011), a broad range of interventions are being used with varying empirical support (Vismara & Rogers, 2010). Early studies of Applied Behavior Analysis (ABA) using Discrete Trial Training (DTT; Lovaas, 1987) and more recent studies of intensive behavioral intervention have documented significant progress in cognitive and language development (Reichow, 2012). There is also increasing support for treatments, recently termed Naturalistic Developmental Behavior Interventions (NDBIs; Rogers et al., 2014; Schreibman et al., 2014) which combine ABA-based treatment with a child-led developmental approach, as in the Early Start Denver Model (ESDM; Dawson et al., 2010). Pivotal Response Treatment (PRT; Mohammadzaheri, Koegel, Rezaee, & Rafiee, 2014) Conflict of interest statement: No conflicts declared.
is an evolution of ABA that also incorporates motivational variables into trials and is conducted in the child’s natural environment. The emerging support for these models warrants additional large-scale, well-controlled studies. Parent involvement is critical for effective intervention with children with ASD (National Research Council, 2001). A few treatment models increase treatment intensity by training parents to deliver intervention (Steiner, Koegel, Koegel, & Whitney, 2012). Research shows parents can implement behavioral interventions (Koegel, Bimbela, & Schreibman, 1996) and autism symptoms subsequently improve (Symon, 2005). Parent education may also promote generalization to natural environments (Steiner et al., 2012) and improve parent psychological well-being (Minjarez, Mercier, Williams, & Hardan, 2013). Therefore, research on interventions that involve parents in treatment delivery is needed. Parent education is a core component of PRT (Koegel, Koegel, Harrower, & Carter, 1999), an NDBI which uses ABA principles to target ‘pivotal’ areas (e.g. motivation). The focus on pivotal areas is hypothesized to result in improvements in broad areas of functioning not directly targeted with intervention (e.g. joint attention; Koegel, Koegel, & Brookman, 2005). Available evidence has demonstrated the efficacy of PRT for teaching social communica-
© 2014 Association for Child and Adolescent Mental Health. Published by John Wiley & Sons Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main St, Malden, MA 02148, USA
2
Antonio Y. Hardan et al.
tion skills (Bryson et al., 2007). However, the majority of PRT research has involved training small numbers of families individually and research has just begun to investigate dissemination through group therapy models (Baker-Ericz en, Stahmer, & Burns, 2007). In an uncontrolled trial of PRT parent training group (N = 17), the majority of parents learned PRT within 10 weeks and their children showed gains in functional communication (Minjarez, Williams, Mercier, & Hardan, 2011). The goal of the present study was to conduct a randomized controlled 12-week trial to examine the effectiveness of PRT, taught to parents in a group format, in targeting functional communication deficits in young children with ASD. A parent psychoeducation control group was selected to examine the unique contribution of parent training in PRT. The primary goals of the study were to evaluate: (a) whether parents learn PRT from a 12-week parent group, and (b) whether children of parents participating in the PRT group exhibit greater improvement in functional communication skills than those receiving general psychoeducation.
Methods Study design This investigation involved a randomized controlled 12-week trial examining the effectiveness of Pivotal Response Treatment Group (PRTG) in targeting functional communication deficits in young children with autism. This study was approved by Stanford University’s institutional review board, and registered in the Clinical Trials database (NCT01881750; http://www. clinicaltrials.gov). The full trial protocol is available upon request.
Participants Recruitment occurred over 2 years (July 2010–June 2012). Participants were recruited through distribution of fliers at clinics and autism awareness events, referral by local professionals, and word of mouth. Following informed consent, a comprehensive evaluation, including review of medical/psychiatric history and completion of psychological assessment batteries, was conducted to determine study eligibility.
Inclusion and exclusion criteria Participants included children: (a) 2–6 years old, (b) diagnosed with autism based on DSM-IV-TR criteria, Autism Diagnostic Interview-Revised (ADI-R; Lord, Rutter, & Le Couteur, 1994), Autism Diagnostic Observation Schedule (ADOS; Lord et al., 2000), and expert clinical judgment, (c) communication-delayed on Preschool Language Scale, 4th Edition (PLS-4; Zimmerman, Steiner, & Pond, 2002; 2- and 3-year olds were ≥ 1 SD below age level, 4-year olds ≥ 2 SDs, and 5–6-year olds ≥ 3 SDs), (d) able to vocalize with intent when prompted by a clinician during the screening visit, (e) with stable concomitant interventions (e.g. ABA, special education, medications, biomedical treatments) for 1 month prior to participation with no planned changes, and (f) with at least one parent available to consistently participate. Exclusion criteria were: (a) participation in more than 60 min weekly of individual speech therapy, (b) comorbid severe psychiatric disorder, (c) genetic abnormal-
ity, and (d) active medical problems. No changes in inclusion or exclusion criteria were applied during the study. The rationale for limiting concomitant speech therapy was due to our interest in studying the effects of PRTG on acquisition of functional communication skills and the concern that the inclusion of children receiving concurrent intensive speech therapy would present a confound. Given that the majority of children in our area get 30–60 min of speech therapy per week it was not practical to exclude children receiving any speech therapy; therefore, the decision was made to limit participation to children receiving routine but not intensive speech therapy.
Procedures After baseline measures, eligible families were randomized in parallel (1:1) to the treatment or control group. Stratification was based on gender, age (2–4:6 vs. 4:7–6:11 years), and intensity of ABA treatment ( .1). Five subjects were excluded (two PRTG and three PEG) due to changes in concomitant therapies during the trial and their data were not included in the analyses. Forty-seven subjects (PRTG = 25; PEG = 22) completed the study with one participant in the PEG group lost to follow-up. No adverse effects were noted in either group. Table 1 Baseline comparison of participants with autism in the Pivotal Response Treatment Group (PRTG) and Psychoeducation Group (PEG)
N Male/Female Mean age in years SLO total utterances CGI-severity score Development quotient Social Responsiveness Scale
PRTG (SD)
PEG (SD)
25 19/6 4.1 (1.2) 45.7 (23.1) 5.2 (0.9) 52.8 (16.4) 77.9 (11.4)
23a 17/6 4.1 (1.3) 40.8 (22.4) 5.1 (0.8) 53.5 (14.8) 78.9 (12.8)
SD, standard deviation; CGI, Clinical global impression; Development quotient measured by Mullen Scales; No statistical differences between the two groups on any of the baseline clinical characteristics. a Includes one subject who was randomized but did not complete the study.
Structured laboratory observation (SLO) Table 2 presents results for total, imitative, and nonverbally prompted utterances from the SLO. Irrespective of group, children showed significant improvement in total number of utterances across study time points (F(2, 43) = 6.12, p = .005; Figure 2). However, individuals receiving PRTG showed greater improvement (F(2, 43) = 3.53, p = .038). The treatment effect was most apparent for imitative (F(2, 43) = 7.67, p = .001) and nonverbally prompted utterances (F(2, 43) = 7.06, p = .002; Table 2). Spontaneous utterances showed a nonsignificant trend toward greater improvement in PRTG (F(2, 44) = 2.99, p = .060). The treatment effect was not significant for unintelligible (F(2, 43) = 0.27, p = .762) or verbally prompted utterances (F(2, 43) = 0.32, p = .725). No parent met fidelity of implementation at baseline. At week 12, 21 of 25 parents in PRTG, and none in the PEG, met fidelity of PRT implementation. Including treatment fidelity as a covariate in regression models further qualified the above-described treatment effects. Within the PRTG, caregivers who demonstrated fidelity at week 12 had children with greater total (F(2, 42) = 6.79, p = .003; Figure S1) and imitative (F(2, 46) = 6.95, p = .002) utterances relative to those who did not meet fidelity. Fidelity did not modify the treatment effect for verbally prompted (F(2, 41) = 0.92, p = .405), nonverbally © 2014 Association for Child and Adolescent Mental Health.
RCT of pivotal response treatment group
5
Table 2 Treatment responses of participants with autism whose parents were assigned to Pivotal Response Treatment Group (PRTG) or Psychoeducation Group (PEG) Group X Time Interaction
Mean (SD) Baseline PRTG (n = 25) SLO Total utterances Unintelligible Imitative Verbally prompted Nonverbally prompted Spontaneous Vineland Communication standard score Expressive raw score Receptive raw score CDI Mean length of longest utterance Words produced out of 396 Words produced out of 680 PLS Expressive standard score SRS total CGI-Severity CGI-Improvement
45.7 (23.1) 27.64 (17.8) 9.7 (7.6) 7.7 (9.3) 0.2 (0.4) 0.5 (1.4) PRTG 69.9 (16.3) 26.7 (12.1) 17.8 (7.1)
Week 12
PEG (n = 23)
PRTG (n = 25)
PEG (n = 22)
F
p
40.8 (22.4) 22.7 (14.2) 6.1 (5.4) 10.7 (10.4) 0.5 (1.1) 0.8 (1.5) PEG 71.6 (15.4)
64.5 (28.9) 26.1 (14.9) 19.4 (14.2) 14.5 (15.2) 2.7 (3.8) 0.9 (1.4) PRTG 78.9 (18.9)
51.4 (33.8) 24.6 (23.3) 7.1 (7.8) 16.0 (17.0) 0.1 (0.3) 0.4 (0.6) PEG 72.8 (16.5)
3.53 0.27 7.67 0.32 7.06 2.99
.038 .762 .001 .725 .002 .06
0.42 0.08 1.06 0.09 0.94 0.46
3.80
.041
0.34
31.3 (18) 18.1 (6.6)
41.7 (14.7) 21.5 (14.7)
34 (18.9) 18.9 (6.5)
6.95 4.27
.004 .028
0.46 0.23
3.09
.059
0.50
0.213 1.30
.736 .284
0.35 0.27
.165 .776 .003 .001
0.07 0.49 0.47 1.14
2.1 (1.7)
2.4 (1.7)
3.7 (2.1)
2.8 (1.4)
137.1 (118.1) 229.3 (183.8)
169.5 (134.2) 179.1 (163.8)
172.2 (123.6) 289.1 (181.9)
215.0 (118.3) 239.9 (187.1)
62.6 (11.2) 77.9 (11.4) 5.2 (0.9) –
63.9 (11.3) 78.9 (12.8) 5.1 (0.8) –
63.9 74.9 4.6 2.4
(11.6) (12.4) (0.9) (0.7)
63.0 80.6 5 3.2
(13.4) (10.7) (0.8) (0.7)
2.00 0.26 6.84 15.97
Cohen’s d (Week 12)
Vineland: Vineland Adaptive Behavior Scales, Second Edition; CDI: MacArthur-Bates Communicative Development Inventories; PLS: Preschool Language Scale, 4th Edition; SRS, Social Responsiveness Scale; CGI: Clinical global impression (focused on social and communication symptoms).
Total utterances
90 80
PEG
70
PRTG
60 50 40 30 20 10 0 Baseline
Week 6
Week 12
Figure 2 Effect of Pivotal Response Treatment Group (PRTG) versus Psychoeducation Group (PEG) on total number of utterances measured during SLO (F(2, 43) = 6.12, p = .005)
prompted (F(2, 42) = 0.87, p = .425), or spontaneous utterances (F(2, 44) = 0.57, p = .567).
Exploratory measures A significant treatment effect was also observed for the Vineland-II Communication scale (F(2, 19) = 3.80, p = .041), with individuals receiving PRTG showing larger improvements in communication (see Table 2). Vineland-II subscales showed a significant treatment effect for expressive (F(2, 23) = 6.95, p = .004) and receptive language raw scores (F(2, 21) = 4.27, p = .028). A nonsignificant © 2014 Association for Child and Adolescent Mental Health.
trend was observed for CDI mean length of longest utterance (F(2, 32) = 3.09, p = .059) with children in the PRTG saying an average of 2.1-word (SD1.7) utterances at baseline and an average of 3.7-word (2.1) utterances at week 12, and children in the PEG increasing from an average mean length of utterance of 2.4 (1.7) to 2.8 (1.4). There were no significant treatment effects for SRS total raw scores (F(2, 42) = 0.26, p = .776), CDI total words out of 396 (F (2, 42) = .213, p = .736), and out of 680 (F(2, 42) = 1.30, p = .284), or PLS-4 expressive language standard scores (F(1,40) = 2.00, p = .165). The treatment effect was observed for CGI-Severity of social and communication symptoms (F(2, 42) = 6.84, p = .003), and CGI-Improvement ratings were significantly better in PRTG relative to PEG at weeks 6 and 12 (F(1, 44) = 15.97, p < .001). The pattern of treatment effects for exploratory measures did not change with fidelity included as a covariate, and fidelity did not significantly modify the treatment effect. Finally, excluding participants receiving PRTG who did not meet fidelity did not alter the findings.
Predictors of response Older children with higher baseline IQ had more total utterances, but there were no effects of sex and
Change in total utterances from baseline to week 12
6
Antonio Y. Hardan et al.
50.00 PEG 40.00
PRTG
30.00 20.00 10.00 0.00 –10.00 –20.00
Low visual reception
High visual reception
Figure 3 Total utterances measured during SLO in Pivotal Response Treatment Group (PRTG) and Psychoeducation Group (PEG) with low and high Mullen visual reception scores (median split; F(2, 40) = 3.96, p = .027)
the treatment effect did not differ across age or sex (largest F(5, 41) = 0.90, p = .492). Baseline Mullen visual reception (VR) scores were a significant predictor of treatment response for total and imitative utterances (smallest Group X Time X Mullen VR interaction F(2, 40) = 3.96, p = .027), accounting for 14% and 18% of the variance in treatment response for total and imitative utterances, respectively. Figure 3 displays total utterances in children receiving PEG and PRTG with low and high VR scores (median split). Treatment response was not modified by baseline PLS total language standard scores, SRS total t-scores, CDI words out of 396 or 680, or CDI sentence length (largest F(2, 41) = 1.50, p = .236).
Discussion Findings from this first randomized controlled trial of group-delivered PRT support using PRT to improve functional communication skills for young children with ASD. PRTG resulted in greater improvement in frequency of functional utterances compared to PEG. These findings are consistent with a recent randomized controlled trial in older children with ASD reporting increase in mean length of utterance in the PRT group compared to controls (Mohammadzaheri et al., 2014). In addition, PRTG participants demonstrated greater improvement in adaptive communication skills as reported by parents. Finally, baseline Mullen VR scores predicted treatment response to PRTG. While PRT is considered an established autism treatment (National Autism Center, 2009), this trial evaluated one of the largest groups of children to be treated with PRT in a research study to date and participants were well-characterized, allowing for further analysis of factors contributing to treatment response. The parent education programs were both provided against a backdrop of community-based treatments including school and speech programming, as well as some ABA programs which were maintained stable during the study. The majority of parents
(21/25) receiving PRTG demonstrated at least 80% PRT fidelity of implementation by week 12 and retention rate was high in PRTG (92%) suggesting good acceptability of the treatment. Child improvements were observed in increased utterances during SLO and in adaptive communication on the Vineland-II. In contrast, supplemental measures of language offered mixed results. While the CDI mean length of longest utterance approached significance, no differences were observed between groups on CDI number of words produced, or PLS expressive standard scores. These findings are consistent with several other studies which have shown that parent education programs may not lead to reliable changes on standardized assessments of language functioning (Smith, Groen, & Wynn, 2000), though improvements may be observed on other language measures (Roberts et al., 2011). These observations also suggest that as a parent-delivered intervention, PRTG may have a greater effect on functional use of skills during everyday interactions. This finding is consistent with the CGI results showing greater improvement in PRTG and greater reduction in severity of social communication impairment when compared with PEG. Future research including multiple measures of skill generalization will be needed to investigate the extent to which child improvement at least in the short-term reflects the parent’s improved ability to elicit functional language and whether this potential mechanism of change has implications for subsequent generalization in child skill across interactive partners and contexts. Longer duration trials may also be warranted to evaluate changes on standardized language measures. Observed gains in total frequency of utterances came primarily from increases in intelligible speech. The greatest increases in PRTG were in imitative utterances, which are consistent with findings from other short-term NDBIs (Ingersoll, Meyer, Bonter, & Jelinek, 2012). This is likely a result of the emphasis in PRT training on the use of maintenance tasks to enhance motivation (Koegel et al., 1989). Nonverbally prompted speech was also shown to increase as a result of PRTG, suggesting parents may have begun incorporating nonverbal prompts as acquisition tasks. Parents in the PEG did use verbal prompts during the SLO at a frequency similar to that observed in the PRTG, but did not naturally use frequent imitative or nonverbal prompting strategies to scaffold child language development. Spontaneous utterances were generally low in frequency, though parents were instructed to actively engage their children, potentially limiting the opportunity for unprompted verbalizations. Future studies should consider home videos or automated measures (e.g. Language ENvironment Analysis system, LENA; Oller et al., 2010) for assessing spontaneous speech. Documented improvements in adaptive communication for the PRTG were consistent with prior © 2014 Association for Child and Adolescent Mental Health.
RCT of pivotal response treatment group
research (Baker-Ericz en et al., 2007). Increases in standard scores suggest a rate of improvement over 12 weeks that is faster than normative expectations and comparable to other controlled trials of early intervention programs (Dawson et al., 2010). Improvement on the Vineland-II is particularly meaningful, as adaptive skills are related to positive prognosis (Kanne et al., 2011). Increases in receptive raw scores suggest spread of effect to receptive skills not explicitly taught (Walton & Ingersoll, 2013). This pattern appears to indicate that participating children increased their understanding of speech as a result of the intervention. It may also reflect the fact that parents became more effective at motivating their children to respond. This finding is consistent with research in children with developmental disabilities, where progress in expressive language was associated with improvement in receptive skills (Walton & Ingersoll, 2013; Wynn & Smith, 2003). Baseline Mullen VR scores predicted language gains in both groups, while gender, age, and other baseline measures did not. Children with high VR scores receiving PRTG had very large improvements in total and imitative utterances, while those with low VR scores had smaller but still meaningful improvements. Children with high VR scores receiving PEG showed modest improvements at week 12, while those with low VR scores did not show improvement. These observations are consistent with reports documenting positive outcomes associated with higher baseline cognitive ability and nonverbal IQ in particular (Magiati, Tay, & Howlin, 2014; Turner & Stone, 2007) and highlight the need to individualize interventions so that effective treatments are implemented early, when the brain is most plastic. Consistent with recommendations regarding the critical role of parent education in early intervention (National Research Council, 2001), this study provided support for the model of training parents to implement PRT. This mechanism for increasing intervention intensity is promising, particularly given the need for cost-effective services (Wise, Little, Holliman, Wise, & Wang, 2010). A recent systematic review of meta-analyses indicated that parent involvement was an important predictor of better child outcomes, especially adaptive behavior gains (Strauss, Mancini, & Fava, 2013). Given that parent education models offer opportunity for enhanced generalization (Steiner et al., 2012), increased service intensity (Kaiser, Hancock, & Nietfeld, 2010; Laski, Charlop, & Schreibman, 1988), and improved parent psychological well-being (Minjarez et al., 2013), additional studies examining effective parent educational models are needed. Delivery of parent training in a group format makes this study unique, as there have been no randomized controlled trials of group PRT to date. With limited access to evidence-based treatments for ASD (Wise et al., 2010), it is especially meaningful to identify efficacious group models, which allow for dissemination to large numbers of children with © 2014 Association for Child and Adolescent Mental Health.
7
time-limited clinician involvement. It is also important to determine whether group models are more effective than individual approaches in subgroups of children or families with specific characteristics. This study had several limitations. The moderate sample size meant that power to detect complex multicomponent patterns was limited. There is also no information available about longer term effects of the treatment. Furthermore, children may have gotten varying doses of PRT depending on the consistency of parent implementation and parents who did not meet fidelity may have learned PRT if given more time. For ethical reasons, it was necessary to allow children to continue community treatments during study. There were also a few differences between the PRTG and PEG including number of individual sessions, qualifications of intervention providers, and use of homework assignments in the PRTG which could have influenced results. There were no data regarding fidelity of treatment implementation by the group parent educators which would be important for future studies. This study also targeted language development only, though there is support for using PRT to target other skills (Koegel, Koegel, Boettcher, Harrower, & Openden, 2006; Schreibman, Stahmer, & Pierce, 1996). Finally, given that parent-report measures (e.g. Vineland-II) cannot be ‘blind’ to treatment condition in a parent education study, more objective behavioral or automated measures such as LENA System (Oller et al., 2010) and measures of in-home implementation would add important information about generalization of skills.
Conclusions The present study represents a step forward in applying rigorous experimental design to evaluate differential treatment effects by comparing an established treatment with general parent psychoeducation. The study also provides support for group-based parent training, offering a promising new approach for dissemination to large numbers of families in an efficient manner. However, additional large randomized controlled trials will be critical for determining the optimal intensity of treatment (Rogers & Vismara, 2008). Supplementing parent training with clinician-delivered intervention and increasing treatment duration may lead to larger gains. Comparing established treatments will also be critical for analysis of predictors of treatment response. Finally, while there is evidence from this and other studies to suggest that PRT may have an impact on social skills (Baker-Ericz en et al., 2007), there is a need for more systematic research into the effects of PRT on social behaviors.
Supporting information Additional Supporting Information may be found in the online version of this article:
8
Antonio Y. Hardan et al.
Appendix S1. Pivotal Response Treatment Group Content. Table S1. Overview of pivotal response treatment group content. Table S2. Overview of psychoeducation group content. Figure S1. Total child utterances (+/– 95% CI) across study weeks. Figure S2. Consort 2010 checklist of information to include when reporting a randomized trial.
not involved in the trial. Data management was supported by the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health, through grant UL1 RR025744. The authors gratefully acknowledge the families for their participation. The authors have declared that they have no competing or potential conflicts of interest.
Correspondence Acknowledgements This work was supported by an Autism Speaks Treatment Grant (#5773; PI: Hardan); the foundation was
Grace Gengoux, Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA; Email: [email protected]
Key points
• • • •
Pivotal Response Treatment (PRT) is a naturalistic developmental behavior intervention (NDBI) focused on motivating children with autism. This is the first randomized controlled trial of group parent training in PRT (PRTG). PRTG resulted in greater improvement in functional speech and adaptive communication, when compared with a psychoeducation group. Additional large-scale studies are needed to identify optimal intensity and explore effects of PRT on other core symptoms.
References American Psychiatric Association (2013). Diagnostic and statistical manual for mental disorders (5th edn). Washington, DC: American Psychiatric Association. Baker-Ericz en, M.J., Stahmer, A.C., & Burns, A. (2007). Child demographics associated with outcomes in a communitybased pivotal response training program. Journal of Positive Behavior Interventions, 9, 52–60. Bryson, S.E., Koegel, L.K., Koegel, R.L., Openden, D., Smith, I.M., & Nefdt, N. (2007). Large scale dissemination and community implementation of pivotal response treatment: Program description and preliminary data. Research and Practice for Persons With Severe Disabilities, 32, 142–153. Center for Disease Control (2014). Prevalence of autism spectrum disorder among children aged 8 years-autism and developmental disabilities monitoring network, 11 sites, United States, 2010. MMWR Surveillance Summaries, 63, 1–21. Cohen, J. (1960). A coefficient of agreement for nominal scales. Educational and Psychological Measurement, 20, 37–46. Constantino, J.N., & Gruber, C.P. (2005). Social responsiveness scale. Los Angeles: Western Psychological Services. Dawson, G., & Burner, K. (2011). Behavioral interventions in children and adolescents with autism spectrum disorder: A review of recent findings. Current Opinion in Pediatrics, 23, 616–620. 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, 17–23. Fenson, L., Marchman, V.A., Thal, D.J., Dale, P.S., Reznick, J.S., & Bates, E. (2007). MacArthur-bates communicative development inventories. Baltimore, MD: Paul H. Brookes Publishing Co. Guy, W. (1976). ECDEU assessment manual for psychopharmacology. Rockville, MD: U.S. Department of Health, Education, and Welfare.
Harris, P.A., Taylor, R., Thielke, R., Payne, J., Gonzalez, N., & Conde, J.G. (2009). Research electronic data capture (REDCap) – A metadata-driven methodology and workflow process for providing translational research informatics support. Journal of Biomedical Informatics, 42, 377–381. Ingersoll, B., Meyer, K., Bonter, N., & Jelinek, S. (2012). A comparison of developmental social–pragmatic and naturalistic behavioral interventions on language use and social engagement in children with autism. Journal of Speech, Language, and Hearing Research, 55, 1301– 1313. Kaiser, A.P., Hancock, T.B., & Nietfeld, J.P. (2010). The effects of parent-implemented enhanced milieu teaching on the social communication of children who have autism. Early Education and Development, 11, 423–446. Kanne, S.M., Gerber, A.J., Quirmbach, L.M., Sparrow, S.S., Cicchetti, D.V., & Saulnier, C.A. (2011). The role of adaptive behavior in autism spectrum disorders: Implications for functional outcome. Journal of Autism and Developmental Disorders, 41, 1007–1018. Koegel, R.L., Bimbela, A., & Schreibman, L. (1996). Collateral effects of parent training on family interactions. Journal of Autism and Developmental Disorders, 26, 347–359. Koegel, R.L., Koegel, L.K., Boettcher, M.A., Harrower, J., & Openden, D. (2006). Combining functional assessment and self-mangagement procedures to rapidly reduce disruptive behaviors. In R.L. Koegel & L.K. Koegel (Eds.), Pivotal response treatments for autism (pp. 245–258). Baltimore, MD: Paul H. Brookes Publishing Company. Koegel, L.K., Koegel, R.L., & Brookman, L.I. (2005). Child-initiated interactions that are pivotal in intervention for children with autism. In E.D. Hibbs & P.S. Jensen (Eds.), Psychosocial treatments for child and adolescent disorders: Empirically based strategies for clinical practice (2nd edn, pp. 633–657). Washington DC: American Psychological Association. Koegel, L.K., Koegel, R.L., Harrower, J.K., & Carter, C.M. (1999). Pivotal response intervention I: Overview of © 2014 Association for Child and Adolescent Mental Health.
RCT of pivotal response treatment group approach. Research and Practice for Persons with Severe Disabilities, 24, 174–185. Koegel, R.L., Schreibman, L., Good, A., Cerniglia, L., Murphy, C., & Koegel, L.K. (1989). How to teach pivotal behaviors to children with autism: A training manual. Santa Barbara, CA: University of California. Laski, K.E., Charlop, M.H., & Schreibman, L. (1988). Training parents to use the natural language paradigm to increase their autistic children’s speech. Journal of Applied Behavior Analysis, 2, 391–400. Lord, C., Risi, S., Lambrecht, L., Cook, E.H., Jr, Leventhal, B.L., DiLavore, P.C., . . . & Rutter, M. (2000). The autism diagnostic observation schedule-generic: A standard measure of social and communication deficits associated with the spectrum of autism. Journal of Autism and Developmental Disorders, 30, 205–223. Lord, C., Rutter, M., & Le Couteur, A. (1994). Autism diagnostic interview-revised: A revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. Journal of Autism and Developmental Disorders, 24, 659–685. Lovaas, O.I. (1987). Behavioral treatment and normal educational and intellectual functioning in young autistic children. Journal of Consulting and Clinical Psychology, 55, 3–9. Magiati, I., Tay, X.W., & Howlin, P. (2014). Cognitive, language, social and behavioural outcomes in adults with autism spectrum disorders: A systematic review of longitudinal follow-up studies in adulthood. Clinical Psychology Reviews, 34, 73–86. Minjarez, M.B., Mercier, E.M., Williams, S.E., & Hardan, A.Y. (2013). Impact of pivotal response training group therapy on stress and empowerment in parents of children with autism. Journal of Positive Behavior Interventions, 15, 71–78. Minjarez, M.B., Williams, S.E., Mercier, E.M., & Hardan, A.Y. (2011). Pivotal response group treatment program for parents of children with autism. Journal of Autism and Developmental Disorders, 41, 92–101. Mohammadzaheri, F., Koegel, L.K., Rezaee, M., & Rafiee, S.M. (2014). A randomized clinical trial comparison between Pivotal Response Treatment (PRT) and structured Applied Behavior Analysis (ABA) intervention for children with autism. Journal of Autism and Developmental Disorders, 44, 2769–2777. Mullen, E.M. (1995). Mullen scales of early learning: AGS edn. Circle Pines, MN: American Guidance Service. National Autism Center (2009). National standards report. Randolph, MA: National Autism center. National Research Council (2001). Educating children with autism. Washington, DC: National Academies Press. Oller, D., Niyogi, P., Gray, S., Richards, J., Gilkerson, J., Xu, D., . . . & Warren, S. (2010). Automated vocal analysis of naturalistic recordings from children with autism, language delay, and typical development. Proceedings of the National Academy of Sciences, 107, 13354–13359. Peugh, J.L., & Enders, C.K. (2005). Using the SPSS mixed procedure to fit cross-sectional and longitudinal multilevel models. Educational and Psychological Measurement, 65, 717–741. Reichow, B. (2012). Overview of meta-analyses on early intensive behavioral intervention for young children with autism spectrum disorders. Journal of Autism and Developmental Disorders, 42, 512–520. Roberts, J., Williams, K., Carter, M., Evans, D., Parmenter, T., Silove, N., . . . & Warren, A. (2011). A randomized controlled trial of two early intervention programs for young children with autism: Centre-based with parent program and
© 2014 Association for Child and Adolescent Mental Health.
9
home-based. Research in Autism Spectrum Disorders, 5, 1553–1566. Rogers, S.J., & Vismara, L.A. (2008). Evidence-based comprehensive treatments for early autism. Journal of Clinical Child & Adolescent Psychology, 37, 8–38. Rogers, S.J., Vismara, L., Wagner, A.L., McCornick, C., Young, G., & Ozonoff, S. (2014). Autism treatment in the first year of life: A pilot study of Infant Start, a parent-implemented intervention for symptomatic infants. Journal of Autism and Developmental Disorders. Advance online publication. doi:10.1007/s10803-014-2202-y. Schreibman, L., Dawson, G., Rogers, S.J., Ingersoll, B., Kaiser, A.P., & Kasari, C., . . . & Halladay, A. (2014). Common elements of research-based practices for toddlers with ASD. Paper presented at the Autism Speaks Toddler Treatment Network Meeting, Atlanta, GA. Schreibman, L., Stahmer, A., & Pierce, K. (1996). Alternative applications of pivotal response training: Teaching symbolic play and social interaction skills. In L.K. Koegel, R.L. Koegel & G. Dunlap (Eds.), Positive behavioral support: Including people with difficult behavior in the community (pp. 353– 371). Baltimore, MD: Paul H. Brookes Publishing Co. Shrout, P.E., & Fleiss, J.L. (1979). Intraclass correlations: Uses in assessing rater reliability. Psychological Bulletin, 86, 420–428. Smith, T., Groen, A.D., & Wynn, J.W. (2000). Randomized trial of intensive early intervention for children with pervasive developmental disorder. American Journal of Mental Retardation, 105, 269–285. Sparrow, S.S., Cicchetti, D.V., & Balla, D.A. (2005). Vineland adaptive behavior scales (2nd edn). San Antonio, TX: Pearson. Steiner, A.M., Koegel, L.K., Koegel, R.L., & Whitney, A.E. (2012). Issues and theoretical constructs regarding parent education for autism spectrum disorders. Journal of Autism and Developmental Disorders, 42, 1218–1227. Strauss, K., Mancini, F., & Fava, L. (2013). Parent inclusion in early intensive behavior interventions for young children with ASD: A synthesis of meta-analyses from 2009 to 2011. Research in Developmental Disabilities, 34, 2967–2985. Symon, J.B. (2005). Expanding interventions for children with autism. Journal of Positive Behavior Interventions, 7, 159–173. Turner, L.M., & Stone, W.L. (2007). Variability in outcome for children with an ASD diagnosis at age two. Journal of Child Psychology and Psychiatry, 48, 793–802. Vismara, L.A., & Rogers, S.J. (2010). Behavioral treatments in autism spectrum disorder: What do we know? Annual Review of Clinical Psychology, 6, 447–468. Walton, K.M., & Ingersoll, B.R. (2013). Improving social skills in adolescents and adults with autism and severe to profound intellectual disability: A review of the literature. Journal of Autism and Developmental Disorders, 43, 594– 615. Wise, M.D., Little, A.A., Holliman, J.B., Wise, P.H., & Wang, J. (2010). Can state early intervention programs meet the increased demand of children suspected of having autism spectrum disorders? Journal of Developmental and Behavioral Pediatrics, 31, 469–476. Wynn, J.W. & Smith, T. (2003). Generalization between receptive and expressive language in young children with autism. Behavioral Interventions, 18, 245–266. Zimmerman, I.L., Steiner, V.G., & Pond, R.E. (2002). Preschool language scale (4th edn). San Antonio, TX: The Psychological Corporation.
Accepted for publication: 20 September 2014
doi:10.1111/jcpp.12354
A randomized controlled trial of Pivotal Response Treatment Group for parents of children with autism Antonio Y. Hardan,1 Grace W. Gengoux,1 Kari L. Berquist,1 Robin A. Libove,1 Christina M. Ardel,1 Jennifer Phillips,1 Thomas W. Frazier,2 and Mendy B. Minjarez3 1
Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA; 2Center for Autism, Cleveland Clinic, Cleveland, OH; 3Seattle Children’s Hospital/Seattle Children’s Research Institute, Seattle, WA, USA
Background: With rates of autism diagnosis continuing to rise, there is an urgent need for effective and efficient service delivery models. Pivotal Response Treatment (PRT) is considered an established treatment for autism spectrum disorder (ASD); however, there have been few well-controlled studies with adequate sample size. The aim of this study was to conduct a randomized controlled trial to evaluate PRT parent training group (PRTG) for targeting language deficits in young children with ASD. Methods: Fifty-three children with autism and significant language delay between 2 and 6 years old were randomized to PRTG (N = 27) or psychoeducation group (PEG; N = 26) for 12 weeks. The PRTG taught parents behavioral techniques to facilitate language development. The PEG taught general information about ASD (clinical trial NCT01881750; http://www.clinicaltrials.gov). Results: Analysis of child utterances during the structured laboratory observation (primary outcome) indicated that, compared with children in the PEG, children in the PRTG demonstrated greater improvement in frequency of utterances (F(2, 43) = 3.53, p = .038, d = 0.42). Results indicated that parents were able to learn PRT in a group format, as the majority of parents in the PRTG (84%) met fidelity of implementation criteria after 12 weeks. Children also demonstrated greater improvement in adaptive communication skills (Vineland-II) following PRTG and baseline Mullen visual reception scores predicted treatment response to PRTG. Conclusions: This is the first randomized controlled trial of group-delivered PRT and one of the largest experimental investigations of the PRT model to date. The findings suggest that specific instruction in PRT results in greater skill acquisition for both parents and children, especially in functional and adaptive communication skills. Further research in PRT is warranted to replicate the observed results and address other core ASD symptoms. Keywords: Language deficits, treatment fidelity, group parent training, social communication, naturalistic developmental behavior intervention.
Introduction Autism spectrum disorder (ASD) is characterized by social communication deficits and repetitive behaviors (American Psychiatric Association, 2013). With greater than 1% of children carrying an ASD diagnosis (Center for Disease Control, 2014), the development of empirically supported treatments for ASD is a critical priority. While early intervention improves cognitive, language, and adaptive skills for many children (Dawson & Burner, 2011), a broad range of interventions are being used with varying empirical support (Vismara & Rogers, 2010). Early studies of Applied Behavior Analysis (ABA) using Discrete Trial Training (DTT; Lovaas, 1987) and more recent studies of intensive behavioral intervention have documented significant progress in cognitive and language development (Reichow, 2012). There is also increasing support for treatments, recently termed Naturalistic Developmental Behavior Interventions (NDBIs; Rogers et al., 2014; Schreibman et al., 2014) which combine ABA-based treatment with a child-led developmental approach, as in the Early Start Denver Model (ESDM; Dawson et al., 2010). Pivotal Response Treatment (PRT; Mohammadzaheri, Koegel, Rezaee, & Rafiee, 2014) Conflict of interest statement: No conflicts declared.
is an evolution of ABA that also incorporates motivational variables into trials and is conducted in the child’s natural environment. The emerging support for these models warrants additional large-scale, well-controlled studies. Parent involvement is critical for effective intervention with children with ASD (National Research Council, 2001). A few treatment models increase treatment intensity by training parents to deliver intervention (Steiner, Koegel, Koegel, & Whitney, 2012). Research shows parents can implement behavioral interventions (Koegel, Bimbela, & Schreibman, 1996) and autism symptoms subsequently improve (Symon, 2005). Parent education may also promote generalization to natural environments (Steiner et al., 2012) and improve parent psychological well-being (Minjarez, Mercier, Williams, & Hardan, 2013). Therefore, research on interventions that involve parents in treatment delivery is needed. Parent education is a core component of PRT (Koegel, Koegel, Harrower, & Carter, 1999), an NDBI which uses ABA principles to target ‘pivotal’ areas (e.g. motivation). The focus on pivotal areas is hypothesized to result in improvements in broad areas of functioning not directly targeted with intervention (e.g. joint attention; Koegel, Koegel, & Brookman, 2005). Available evidence has demonstrated the efficacy of PRT for teaching social communica-
© 2014 Association for Child and Adolescent Mental Health. Published by John Wiley & Sons Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main St, Malden, MA 02148, USA
2
Antonio Y. Hardan et al.
tion skills (Bryson et al., 2007). However, the majority of PRT research has involved training small numbers of families individually and research has just begun to investigate dissemination through group therapy models (Baker-Ericz en, Stahmer, & Burns, 2007). In an uncontrolled trial of PRT parent training group (N = 17), the majority of parents learned PRT within 10 weeks and their children showed gains in functional communication (Minjarez, Williams, Mercier, & Hardan, 2011). The goal of the present study was to conduct a randomized controlled 12-week trial to examine the effectiveness of PRT, taught to parents in a group format, in targeting functional communication deficits in young children with ASD. A parent psychoeducation control group was selected to examine the unique contribution of parent training in PRT. The primary goals of the study were to evaluate: (a) whether parents learn PRT from a 12-week parent group, and (b) whether children of parents participating in the PRT group exhibit greater improvement in functional communication skills than those receiving general psychoeducation.
Methods Study design This investigation involved a randomized controlled 12-week trial examining the effectiveness of Pivotal Response Treatment Group (PRTG) in targeting functional communication deficits in young children with autism. This study was approved by Stanford University’s institutional review board, and registered in the Clinical Trials database (NCT01881750; http://www. clinicaltrials.gov). The full trial protocol is available upon request.
Participants Recruitment occurred over 2 years (July 2010–June 2012). Participants were recruited through distribution of fliers at clinics and autism awareness events, referral by local professionals, and word of mouth. Following informed consent, a comprehensive evaluation, including review of medical/psychiatric history and completion of psychological assessment batteries, was conducted to determine study eligibility.
Inclusion and exclusion criteria Participants included children: (a) 2–6 years old, (b) diagnosed with autism based on DSM-IV-TR criteria, Autism Diagnostic Interview-Revised (ADI-R; Lord, Rutter, & Le Couteur, 1994), Autism Diagnostic Observation Schedule (ADOS; Lord et al., 2000), and expert clinical judgment, (c) communication-delayed on Preschool Language Scale, 4th Edition (PLS-4; Zimmerman, Steiner, & Pond, 2002; 2- and 3-year olds were ≥ 1 SD below age level, 4-year olds ≥ 2 SDs, and 5–6-year olds ≥ 3 SDs), (d) able to vocalize with intent when prompted by a clinician during the screening visit, (e) with stable concomitant interventions (e.g. ABA, special education, medications, biomedical treatments) for 1 month prior to participation with no planned changes, and (f) with at least one parent available to consistently participate. Exclusion criteria were: (a) participation in more than 60 min weekly of individual speech therapy, (b) comorbid severe psychiatric disorder, (c) genetic abnormal-
ity, and (d) active medical problems. No changes in inclusion or exclusion criteria were applied during the study. The rationale for limiting concomitant speech therapy was due to our interest in studying the effects of PRTG on acquisition of functional communication skills and the concern that the inclusion of children receiving concurrent intensive speech therapy would present a confound. Given that the majority of children in our area get 30–60 min of speech therapy per week it was not practical to exclude children receiving any speech therapy; therefore, the decision was made to limit participation to children receiving routine but not intensive speech therapy.
Procedures After baseline measures, eligible families were randomized in parallel (1:1) to the treatment or control group. Stratification was based on gender, age (2–4:6 vs. 4:7–6:11 years), and intensity of ABA treatment ( .1). Five subjects were excluded (two PRTG and three PEG) due to changes in concomitant therapies during the trial and their data were not included in the analyses. Forty-seven subjects (PRTG = 25; PEG = 22) completed the study with one participant in the PEG group lost to follow-up. No adverse effects were noted in either group. Table 1 Baseline comparison of participants with autism in the Pivotal Response Treatment Group (PRTG) and Psychoeducation Group (PEG)
N Male/Female Mean age in years SLO total utterances CGI-severity score Development quotient Social Responsiveness Scale
PRTG (SD)
PEG (SD)
25 19/6 4.1 (1.2) 45.7 (23.1) 5.2 (0.9) 52.8 (16.4) 77.9 (11.4)
23a 17/6 4.1 (1.3) 40.8 (22.4) 5.1 (0.8) 53.5 (14.8) 78.9 (12.8)
SD, standard deviation; CGI, Clinical global impression; Development quotient measured by Mullen Scales; No statistical differences between the two groups on any of the baseline clinical characteristics. a Includes one subject who was randomized but did not complete the study.
Structured laboratory observation (SLO) Table 2 presents results for total, imitative, and nonverbally prompted utterances from the SLO. Irrespective of group, children showed significant improvement in total number of utterances across study time points (F(2, 43) = 6.12, p = .005; Figure 2). However, individuals receiving PRTG showed greater improvement (F(2, 43) = 3.53, p = .038). The treatment effect was most apparent for imitative (F(2, 43) = 7.67, p = .001) and nonverbally prompted utterances (F(2, 43) = 7.06, p = .002; Table 2). Spontaneous utterances showed a nonsignificant trend toward greater improvement in PRTG (F(2, 44) = 2.99, p = .060). The treatment effect was not significant for unintelligible (F(2, 43) = 0.27, p = .762) or verbally prompted utterances (F(2, 43) = 0.32, p = .725). No parent met fidelity of implementation at baseline. At week 12, 21 of 25 parents in PRTG, and none in the PEG, met fidelity of PRT implementation. Including treatment fidelity as a covariate in regression models further qualified the above-described treatment effects. Within the PRTG, caregivers who demonstrated fidelity at week 12 had children with greater total (F(2, 42) = 6.79, p = .003; Figure S1) and imitative (F(2, 46) = 6.95, p = .002) utterances relative to those who did not meet fidelity. Fidelity did not modify the treatment effect for verbally prompted (F(2, 41) = 0.92, p = .405), nonverbally © 2014 Association for Child and Adolescent Mental Health.
RCT of pivotal response treatment group
5
Table 2 Treatment responses of participants with autism whose parents were assigned to Pivotal Response Treatment Group (PRTG) or Psychoeducation Group (PEG) Group X Time Interaction
Mean (SD) Baseline PRTG (n = 25) SLO Total utterances Unintelligible Imitative Verbally prompted Nonverbally prompted Spontaneous Vineland Communication standard score Expressive raw score Receptive raw score CDI Mean length of longest utterance Words produced out of 396 Words produced out of 680 PLS Expressive standard score SRS total CGI-Severity CGI-Improvement
45.7 (23.1) 27.64 (17.8) 9.7 (7.6) 7.7 (9.3) 0.2 (0.4) 0.5 (1.4) PRTG 69.9 (16.3) 26.7 (12.1) 17.8 (7.1)
Week 12
PEG (n = 23)
PRTG (n = 25)
PEG (n = 22)
F
p
40.8 (22.4) 22.7 (14.2) 6.1 (5.4) 10.7 (10.4) 0.5 (1.1) 0.8 (1.5) PEG 71.6 (15.4)
64.5 (28.9) 26.1 (14.9) 19.4 (14.2) 14.5 (15.2) 2.7 (3.8) 0.9 (1.4) PRTG 78.9 (18.9)
51.4 (33.8) 24.6 (23.3) 7.1 (7.8) 16.0 (17.0) 0.1 (0.3) 0.4 (0.6) PEG 72.8 (16.5)
3.53 0.27 7.67 0.32 7.06 2.99
.038 .762 .001 .725 .002 .06
0.42 0.08 1.06 0.09 0.94 0.46
3.80
.041
0.34
31.3 (18) 18.1 (6.6)
41.7 (14.7) 21.5 (14.7)
34 (18.9) 18.9 (6.5)
6.95 4.27
.004 .028
0.46 0.23
3.09
.059
0.50
0.213 1.30
.736 .284
0.35 0.27
.165 .776 .003 .001
0.07 0.49 0.47 1.14
2.1 (1.7)
2.4 (1.7)
3.7 (2.1)
2.8 (1.4)
137.1 (118.1) 229.3 (183.8)
169.5 (134.2) 179.1 (163.8)
172.2 (123.6) 289.1 (181.9)
215.0 (118.3) 239.9 (187.1)
62.6 (11.2) 77.9 (11.4) 5.2 (0.9) –
63.9 (11.3) 78.9 (12.8) 5.1 (0.8) –
63.9 74.9 4.6 2.4
(11.6) (12.4) (0.9) (0.7)
63.0 80.6 5 3.2
(13.4) (10.7) (0.8) (0.7)
2.00 0.26 6.84 15.97
Cohen’s d (Week 12)
Vineland: Vineland Adaptive Behavior Scales, Second Edition; CDI: MacArthur-Bates Communicative Development Inventories; PLS: Preschool Language Scale, 4th Edition; SRS, Social Responsiveness Scale; CGI: Clinical global impression (focused on social and communication symptoms).
Total utterances
90 80
PEG
70
PRTG
60 50 40 30 20 10 0 Baseline
Week 6
Week 12
Figure 2 Effect of Pivotal Response Treatment Group (PRTG) versus Psychoeducation Group (PEG) on total number of utterances measured during SLO (F(2, 43) = 6.12, p = .005)
prompted (F(2, 42) = 0.87, p = .425), or spontaneous utterances (F(2, 44) = 0.57, p = .567).
Exploratory measures A significant treatment effect was also observed for the Vineland-II Communication scale (F(2, 19) = 3.80, p = .041), with individuals receiving PRTG showing larger improvements in communication (see Table 2). Vineland-II subscales showed a significant treatment effect for expressive (F(2, 23) = 6.95, p = .004) and receptive language raw scores (F(2, 21) = 4.27, p = .028). A nonsignificant © 2014 Association for Child and Adolescent Mental Health.
trend was observed for CDI mean length of longest utterance (F(2, 32) = 3.09, p = .059) with children in the PRTG saying an average of 2.1-word (SD1.7) utterances at baseline and an average of 3.7-word (2.1) utterances at week 12, and children in the PEG increasing from an average mean length of utterance of 2.4 (1.7) to 2.8 (1.4). There were no significant treatment effects for SRS total raw scores (F(2, 42) = 0.26, p = .776), CDI total words out of 396 (F (2, 42) = .213, p = .736), and out of 680 (F(2, 42) = 1.30, p = .284), or PLS-4 expressive language standard scores (F(1,40) = 2.00, p = .165). The treatment effect was observed for CGI-Severity of social and communication symptoms (F(2, 42) = 6.84, p = .003), and CGI-Improvement ratings were significantly better in PRTG relative to PEG at weeks 6 and 12 (F(1, 44) = 15.97, p < .001). The pattern of treatment effects for exploratory measures did not change with fidelity included as a covariate, and fidelity did not significantly modify the treatment effect. Finally, excluding participants receiving PRTG who did not meet fidelity did not alter the findings.
Predictors of response Older children with higher baseline IQ had more total utterances, but there were no effects of sex and
Change in total utterances from baseline to week 12
6
Antonio Y. Hardan et al.
50.00 PEG 40.00
PRTG
30.00 20.00 10.00 0.00 –10.00 –20.00
Low visual reception
High visual reception
Figure 3 Total utterances measured during SLO in Pivotal Response Treatment Group (PRTG) and Psychoeducation Group (PEG) with low and high Mullen visual reception scores (median split; F(2, 40) = 3.96, p = .027)
the treatment effect did not differ across age or sex (largest F(5, 41) = 0.90, p = .492). Baseline Mullen visual reception (VR) scores were a significant predictor of treatment response for total and imitative utterances (smallest Group X Time X Mullen VR interaction F(2, 40) = 3.96, p = .027), accounting for 14% and 18% of the variance in treatment response for total and imitative utterances, respectively. Figure 3 displays total utterances in children receiving PEG and PRTG with low and high VR scores (median split). Treatment response was not modified by baseline PLS total language standard scores, SRS total t-scores, CDI words out of 396 or 680, or CDI sentence length (largest F(2, 41) = 1.50, p = .236).
Discussion Findings from this first randomized controlled trial of group-delivered PRT support using PRT to improve functional communication skills for young children with ASD. PRTG resulted in greater improvement in frequency of functional utterances compared to PEG. These findings are consistent with a recent randomized controlled trial in older children with ASD reporting increase in mean length of utterance in the PRT group compared to controls (Mohammadzaheri et al., 2014). In addition, PRTG participants demonstrated greater improvement in adaptive communication skills as reported by parents. Finally, baseline Mullen VR scores predicted treatment response to PRTG. While PRT is considered an established autism treatment (National Autism Center, 2009), this trial evaluated one of the largest groups of children to be treated with PRT in a research study to date and participants were well-characterized, allowing for further analysis of factors contributing to treatment response. The parent education programs were both provided against a backdrop of community-based treatments including school and speech programming, as well as some ABA programs which were maintained stable during the study. The majority of parents
(21/25) receiving PRTG demonstrated at least 80% PRT fidelity of implementation by week 12 and retention rate was high in PRTG (92%) suggesting good acceptability of the treatment. Child improvements were observed in increased utterances during SLO and in adaptive communication on the Vineland-II. In contrast, supplemental measures of language offered mixed results. While the CDI mean length of longest utterance approached significance, no differences were observed between groups on CDI number of words produced, or PLS expressive standard scores. These findings are consistent with several other studies which have shown that parent education programs may not lead to reliable changes on standardized assessments of language functioning (Smith, Groen, & Wynn, 2000), though improvements may be observed on other language measures (Roberts et al., 2011). These observations also suggest that as a parent-delivered intervention, PRTG may have a greater effect on functional use of skills during everyday interactions. This finding is consistent with the CGI results showing greater improvement in PRTG and greater reduction in severity of social communication impairment when compared with PEG. Future research including multiple measures of skill generalization will be needed to investigate the extent to which child improvement at least in the short-term reflects the parent’s improved ability to elicit functional language and whether this potential mechanism of change has implications for subsequent generalization in child skill across interactive partners and contexts. Longer duration trials may also be warranted to evaluate changes on standardized language measures. Observed gains in total frequency of utterances came primarily from increases in intelligible speech. The greatest increases in PRTG were in imitative utterances, which are consistent with findings from other short-term NDBIs (Ingersoll, Meyer, Bonter, & Jelinek, 2012). This is likely a result of the emphasis in PRT training on the use of maintenance tasks to enhance motivation (Koegel et al., 1989). Nonverbally prompted speech was also shown to increase as a result of PRTG, suggesting parents may have begun incorporating nonverbal prompts as acquisition tasks. Parents in the PEG did use verbal prompts during the SLO at a frequency similar to that observed in the PRTG, but did not naturally use frequent imitative or nonverbal prompting strategies to scaffold child language development. Spontaneous utterances were generally low in frequency, though parents were instructed to actively engage their children, potentially limiting the opportunity for unprompted verbalizations. Future studies should consider home videos or automated measures (e.g. Language ENvironment Analysis system, LENA; Oller et al., 2010) for assessing spontaneous speech. Documented improvements in adaptive communication for the PRTG were consistent with prior © 2014 Association for Child and Adolescent Mental Health.
RCT of pivotal response treatment group
research (Baker-Ericz en et al., 2007). Increases in standard scores suggest a rate of improvement over 12 weeks that is faster than normative expectations and comparable to other controlled trials of early intervention programs (Dawson et al., 2010). Improvement on the Vineland-II is particularly meaningful, as adaptive skills are related to positive prognosis (Kanne et al., 2011). Increases in receptive raw scores suggest spread of effect to receptive skills not explicitly taught (Walton & Ingersoll, 2013). This pattern appears to indicate that participating children increased their understanding of speech as a result of the intervention. It may also reflect the fact that parents became more effective at motivating their children to respond. This finding is consistent with research in children with developmental disabilities, where progress in expressive language was associated with improvement in receptive skills (Walton & Ingersoll, 2013; Wynn & Smith, 2003). Baseline Mullen VR scores predicted language gains in both groups, while gender, age, and other baseline measures did not. Children with high VR scores receiving PRTG had very large improvements in total and imitative utterances, while those with low VR scores had smaller but still meaningful improvements. Children with high VR scores receiving PEG showed modest improvements at week 12, while those with low VR scores did not show improvement. These observations are consistent with reports documenting positive outcomes associated with higher baseline cognitive ability and nonverbal IQ in particular (Magiati, Tay, & Howlin, 2014; Turner & Stone, 2007) and highlight the need to individualize interventions so that effective treatments are implemented early, when the brain is most plastic. Consistent with recommendations regarding the critical role of parent education in early intervention (National Research Council, 2001), this study provided support for the model of training parents to implement PRT. This mechanism for increasing intervention intensity is promising, particularly given the need for cost-effective services (Wise, Little, Holliman, Wise, & Wang, 2010). A recent systematic review of meta-analyses indicated that parent involvement was an important predictor of better child outcomes, especially adaptive behavior gains (Strauss, Mancini, & Fava, 2013). Given that parent education models offer opportunity for enhanced generalization (Steiner et al., 2012), increased service intensity (Kaiser, Hancock, & Nietfeld, 2010; Laski, Charlop, & Schreibman, 1988), and improved parent psychological well-being (Minjarez et al., 2013), additional studies examining effective parent educational models are needed. Delivery of parent training in a group format makes this study unique, as there have been no randomized controlled trials of group PRT to date. With limited access to evidence-based treatments for ASD (Wise et al., 2010), it is especially meaningful to identify efficacious group models, which allow for dissemination to large numbers of children with © 2014 Association for Child and Adolescent Mental Health.
7
time-limited clinician involvement. It is also important to determine whether group models are more effective than individual approaches in subgroups of children or families with specific characteristics. This study had several limitations. The moderate sample size meant that power to detect complex multicomponent patterns was limited. There is also no information available about longer term effects of the treatment. Furthermore, children may have gotten varying doses of PRT depending on the consistency of parent implementation and parents who did not meet fidelity may have learned PRT if given more time. For ethical reasons, it was necessary to allow children to continue community treatments during study. There were also a few differences between the PRTG and PEG including number of individual sessions, qualifications of intervention providers, and use of homework assignments in the PRTG which could have influenced results. There were no data regarding fidelity of treatment implementation by the group parent educators which would be important for future studies. This study also targeted language development only, though there is support for using PRT to target other skills (Koegel, Koegel, Boettcher, Harrower, & Openden, 2006; Schreibman, Stahmer, & Pierce, 1996). Finally, given that parent-report measures (e.g. Vineland-II) cannot be ‘blind’ to treatment condition in a parent education study, more objective behavioral or automated measures such as LENA System (Oller et al., 2010) and measures of in-home implementation would add important information about generalization of skills.
Conclusions The present study represents a step forward in applying rigorous experimental design to evaluate differential treatment effects by comparing an established treatment with general parent psychoeducation. The study also provides support for group-based parent training, offering a promising new approach for dissemination to large numbers of families in an efficient manner. However, additional large randomized controlled trials will be critical for determining the optimal intensity of treatment (Rogers & Vismara, 2008). Supplementing parent training with clinician-delivered intervention and increasing treatment duration may lead to larger gains. Comparing established treatments will also be critical for analysis of predictors of treatment response. Finally, while there is evidence from this and other studies to suggest that PRT may have an impact on social skills (Baker-Ericz en et al., 2007), there is a need for more systematic research into the effects of PRT on social behaviors.
Supporting information Additional Supporting Information may be found in the online version of this article:
8
Antonio Y. Hardan et al.
Appendix S1. Pivotal Response Treatment Group Content. Table S1. Overview of pivotal response treatment group content. Table S2. Overview of psychoeducation group content. Figure S1. Total child utterances (+/– 95% CI) across study weeks. Figure S2. Consort 2010 checklist of information to include when reporting a randomized trial.
not involved in the trial. Data management was supported by the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health, through grant UL1 RR025744. The authors gratefully acknowledge the families for their participation. The authors have declared that they have no competing or potential conflicts of interest.
Correspondence Acknowledgements This work was supported by an Autism Speaks Treatment Grant (#5773; PI: Hardan); the foundation was
Grace Gengoux, Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA; Email: [email protected]
Key points
• • • •
Pivotal Response Treatment (PRT) is a naturalistic developmental behavior intervention (NDBI) focused on motivating children with autism. This is the first randomized controlled trial of group parent training in PRT (PRTG). PRTG resulted in greater improvement in functional speech and adaptive communication, when compared with a psychoeducation group. Additional large-scale studies are needed to identify optimal intensity and explore effects of PRT on other core symptoms.
References American Psychiatric Association (2013). Diagnostic and statistical manual for mental disorders (5th edn). Washington, DC: American Psychiatric Association. Baker-Ericz en, M.J., Stahmer, A.C., & Burns, A. (2007). Child demographics associated with outcomes in a communitybased pivotal response training program. Journal of Positive Behavior Interventions, 9, 52–60. Bryson, S.E., Koegel, L.K., Koegel, R.L., Openden, D., Smith, I.M., & Nefdt, N. (2007). Large scale dissemination and community implementation of pivotal response treatment: Program description and preliminary data. Research and Practice for Persons With Severe Disabilities, 32, 142–153. Center for Disease Control (2014). Prevalence of autism spectrum disorder among children aged 8 years-autism and developmental disabilities monitoring network, 11 sites, United States, 2010. MMWR Surveillance Summaries, 63, 1–21. Cohen, J. (1960). A coefficient of agreement for nominal scales. Educational and Psychological Measurement, 20, 37–46. Constantino, J.N., & Gruber, C.P. (2005). Social responsiveness scale. Los Angeles: Western Psychological Services. Dawson, G., & Burner, K. (2011). Behavioral interventions in children and adolescents with autism spectrum disorder: A review of recent findings. Current Opinion in Pediatrics, 23, 616–620. 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, 17–23. Fenson, L., Marchman, V.A., Thal, D.J., Dale, P.S., Reznick, J.S., & Bates, E. (2007). MacArthur-bates communicative development inventories. Baltimore, MD: Paul H. Brookes Publishing Co. Guy, W. (1976). ECDEU assessment manual for psychopharmacology. Rockville, MD: U.S. Department of Health, Education, and Welfare.
Harris, P.A., Taylor, R., Thielke, R., Payne, J., Gonzalez, N., & Conde, J.G. (2009). Research electronic data capture (REDCap) – A metadata-driven methodology and workflow process for providing translational research informatics support. Journal of Biomedical Informatics, 42, 377–381. Ingersoll, B., Meyer, K., Bonter, N., & Jelinek, S. (2012). A comparison of developmental social–pragmatic and naturalistic behavioral interventions on language use and social engagement in children with autism. Journal of Speech, Language, and Hearing Research, 55, 1301– 1313. Kaiser, A.P., Hancock, T.B., & Nietfeld, J.P. (2010). The effects of parent-implemented enhanced milieu teaching on the social communication of children who have autism. Early Education and Development, 11, 423–446. Kanne, S.M., Gerber, A.J., Quirmbach, L.M., Sparrow, S.S., Cicchetti, D.V., & Saulnier, C.A. (2011). The role of adaptive behavior in autism spectrum disorders: Implications for functional outcome. Journal of Autism and Developmental Disorders, 41, 1007–1018. Koegel, R.L., Bimbela, A., & Schreibman, L. (1996). Collateral effects of parent training on family interactions. Journal of Autism and Developmental Disorders, 26, 347–359. Koegel, R.L., Koegel, L.K., Boettcher, M.A., Harrower, J., & Openden, D. (2006). Combining functional assessment and self-mangagement procedures to rapidly reduce disruptive behaviors. In R.L. Koegel & L.K. Koegel (Eds.), Pivotal response treatments for autism (pp. 245–258). Baltimore, MD: Paul H. Brookes Publishing Company. Koegel, L.K., Koegel, R.L., & Brookman, L.I. (2005). Child-initiated interactions that are pivotal in intervention for children with autism. In E.D. Hibbs & P.S. Jensen (Eds.), Psychosocial treatments for child and adolescent disorders: Empirically based strategies for clinical practice (2nd edn, pp. 633–657). Washington DC: American Psychological Association. Koegel, L.K., Koegel, R.L., Harrower, J.K., & Carter, C.M. (1999). Pivotal response intervention I: Overview of © 2014 Association for Child and Adolescent Mental Health.
RCT of pivotal response treatment group approach. Research and Practice for Persons with Severe Disabilities, 24, 174–185. Koegel, R.L., Schreibman, L., Good, A., Cerniglia, L., Murphy, C., & Koegel, L.K. (1989). How to teach pivotal behaviors to children with autism: A training manual. Santa Barbara, CA: University of California. Laski, K.E., Charlop, M.H., & Schreibman, L. (1988). Training parents to use the natural language paradigm to increase their autistic children’s speech. Journal of Applied Behavior Analysis, 2, 391–400. Lord, C., Risi, S., Lambrecht, L., Cook, E.H., Jr, Leventhal, B.L., DiLavore, P.C., . . . & Rutter, M. (2000). The autism diagnostic observation schedule-generic: A standard measure of social and communication deficits associated with the spectrum of autism. Journal of Autism and Developmental Disorders, 30, 205–223. Lord, C., Rutter, M., & Le Couteur, A. (1994). Autism diagnostic interview-revised: A revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. Journal of Autism and Developmental Disorders, 24, 659–685. Lovaas, O.I. (1987). Behavioral treatment and normal educational and intellectual functioning in young autistic children. Journal of Consulting and Clinical Psychology, 55, 3–9. Magiati, I., Tay, X.W., & Howlin, P. (2014). Cognitive, language, social and behavioural outcomes in adults with autism spectrum disorders: A systematic review of longitudinal follow-up studies in adulthood. Clinical Psychology Reviews, 34, 73–86. Minjarez, M.B., Mercier, E.M., Williams, S.E., & Hardan, A.Y. (2013). Impact of pivotal response training group therapy on stress and empowerment in parents of children with autism. Journal of Positive Behavior Interventions, 15, 71–78. Minjarez, M.B., Williams, S.E., Mercier, E.M., & Hardan, A.Y. (2011). Pivotal response group treatment program for parents of children with autism. Journal of Autism and Developmental Disorders, 41, 92–101. Mohammadzaheri, F., Koegel, L.K., Rezaee, M., & Rafiee, S.M. (2014). A randomized clinical trial comparison between Pivotal Response Treatment (PRT) and structured Applied Behavior Analysis (ABA) intervention for children with autism. Journal of Autism and Developmental Disorders, 44, 2769–2777. Mullen, E.M. (1995). Mullen scales of early learning: AGS edn. Circle Pines, MN: American Guidance Service. National Autism Center (2009). National standards report. Randolph, MA: National Autism center. National Research Council (2001). Educating children with autism. Washington, DC: National Academies Press. Oller, D., Niyogi, P., Gray, S., Richards, J., Gilkerson, J., Xu, D., . . . & Warren, S. (2010). Automated vocal analysis of naturalistic recordings from children with autism, language delay, and typical development. Proceedings of the National Academy of Sciences, 107, 13354–13359. Peugh, J.L., & Enders, C.K. (2005). Using the SPSS mixed procedure to fit cross-sectional and longitudinal multilevel models. Educational and Psychological Measurement, 65, 717–741. Reichow, B. (2012). Overview of meta-analyses on early intensive behavioral intervention for young children with autism spectrum disorders. Journal of Autism and Developmental Disorders, 42, 512–520. Roberts, J., Williams, K., Carter, M., Evans, D., Parmenter, T., Silove, N., . . . & Warren, A. (2011). A randomized controlled trial of two early intervention programs for young children with autism: Centre-based with parent program and
© 2014 Association for Child and Adolescent Mental Health.
9
home-based. Research in Autism Spectrum Disorders, 5, 1553–1566. Rogers, S.J., & Vismara, L.A. (2008). Evidence-based comprehensive treatments for early autism. Journal of Clinical Child & Adolescent Psychology, 37, 8–38. Rogers, S.J., Vismara, L., Wagner, A.L., McCornick, C., Young, G., & Ozonoff, S. (2014). Autism treatment in the first year of life: A pilot study of Infant Start, a parent-implemented intervention for symptomatic infants. Journal of Autism and Developmental Disorders. Advance online publication. doi:10.1007/s10803-014-2202-y. Schreibman, L., Dawson, G., Rogers, S.J., Ingersoll, B., Kaiser, A.P., & Kasari, C., . . . & Halladay, A. (2014). Common elements of research-based practices for toddlers with ASD. Paper presented at the Autism Speaks Toddler Treatment Network Meeting, Atlanta, GA. Schreibman, L., Stahmer, A., & Pierce, K. (1996). Alternative applications of pivotal response training: Teaching symbolic play and social interaction skills. In L.K. Koegel, R.L. Koegel & G. Dunlap (Eds.), Positive behavioral support: Including people with difficult behavior in the community (pp. 353– 371). Baltimore, MD: Paul H. Brookes Publishing Co. Shrout, P.E., & Fleiss, J.L. (1979). Intraclass correlations: Uses in assessing rater reliability. Psychological Bulletin, 86, 420–428. Smith, T., Groen, A.D., & Wynn, J.W. (2000). Randomized trial of intensive early intervention for children with pervasive developmental disorder. American Journal of Mental Retardation, 105, 269–285. Sparrow, S.S., Cicchetti, D.V., & Balla, D.A. (2005). Vineland adaptive behavior scales (2nd edn). San Antonio, TX: Pearson. Steiner, A.M., Koegel, L.K., Koegel, R.L., & Whitney, A.E. (2012). Issues and theoretical constructs regarding parent education for autism spectrum disorders. Journal of Autism and Developmental Disorders, 42, 1218–1227. Strauss, K., Mancini, F., & Fava, L. (2013). Parent inclusion in early intensive behavior interventions for young children with ASD: A synthesis of meta-analyses from 2009 to 2011. Research in Developmental Disabilities, 34, 2967–2985. Symon, J.B. (2005). Expanding interventions for children with autism. Journal of Positive Behavior Interventions, 7, 159–173. Turner, L.M., & Stone, W.L. (2007). Variability in outcome for children with an ASD diagnosis at age two. Journal of Child Psychology and Psychiatry, 48, 793–802. Vismara, L.A., & Rogers, S.J. (2010). Behavioral treatments in autism spectrum disorder: What do we know? Annual Review of Clinical Psychology, 6, 447–468. Walton, K.M., & Ingersoll, B.R. (2013). Improving social skills in adolescents and adults with autism and severe to profound intellectual disability: A review of the literature. Journal of Autism and Developmental Disorders, 43, 594– 615. Wise, M.D., Little, A.A., Holliman, J.B., Wise, P.H., & Wang, J. (2010). Can state early intervention programs meet the increased demand of children suspected of having autism spectrum disorders? Journal of Developmental and Behavioral Pediatrics, 31, 469–476. Wynn, J.W. & Smith, T. (2003). Generalization between receptive and expressive language in young children with autism. Behavioral Interventions, 18, 245–266. Zimmerman, I.L., Steiner, V.G., & Pond, R.E. (2002). Preschool language scale (4th edn). San Antonio, TX: The Psychological Corporation.
Accepted for publication: 20 September 2014
