Comparing Imitation Responding and IBT for
children with ASD, a preschool intervention
Birgitta Spjut Janson
1,2,3, Mikael Heimann
4and Tomas Tjus
11
University of Gothenburg, Sweden;2Child and Adolescent Habilitation & Health Unit, Sweden;3Queen Silvia Children’s Hospital, Gothenburg, Sweden;4Link€oping University, Sweden
Key words: Autism spectrum disorader, Preschool children, IBT, intervention - imitation.
The present study examined the effectiveness of two interventions, Imitation Responding (IR) and Intensive Behavior Treatment (IBT) used as initial treatment programs for autistic children enrolled in ordinary preschools. The interventions were car-ried out by parents and/or preschool teachers with supervision from Child Adolescent Habilitation and Health Clinics. Children were randomly assigned to either the IR group or the IBT group. The IR group received a new focused imitation treatment aver-aging 2.2 hours per week, while the children in the IBT group received 14.4 hours treatment per week. The outcome was measured with subscales from PEP-3 and Vineland-II, covering language and social domains. The between-group comparison revealed no significant differences in effect of treatment during the 5 months that encompassed the period from pre- to posttest. Within-group com-parisons revealed significant changes on four sub-scales for the IR-group, with the highest effect sizes for play and expressive language, while for the children in the IBT-group a significant gain was evident for five subscales with the highest effect sizes observed for expressive and receptive lan-guage. These findings suggest that IR can be used as an initial and complementary method in settings where IBT is usually the primary treatment of choice.
Introduction
Autism spectrum disorder (ASD) is a neurodevelopmental condition that includes deficits in social communication, such as social interactions and non-verbal communication. Social cognitive development difficulties, such as reduced joint attention and a similarly reduced capacity to imitate, are more common in young children with ASD (Carpen-ter, Pennington and Rogers, 2002; Charman, Baron-Cohen, Swettenham, et al., 2003; Gopnik, Capps and Meltzoff, 2000; Noris, Nadel, Barker, et al., 2012; Toth, Munson, Meltzoff, et al., 2006; Vivanti and Rogers, 2011). In this paper, we focus on a specific aspect of
imitation, what is termed the ‘being-imitated strategy’ (Contaldo, Colombi, Narzisi, et al., 2016), in which a dedicated preschool teacher imitates the child with the aim of increasing the child’s social interest and motiva-tion to communicate and imitate. Although impairment in imitation has often been reported in children with autism, not all aspects of imitation have been shown to be affected to the same extent (Heimann, Nordqvist, Strid, et al., 2016; Vivanti and Hamilton, 2014).
The specific ‘being-imitated strategy’ used in IR, is a manualised intervention, based on Nadel’s theory and empirical findings (Nadel, 2000, 2002, 2006). Nadel claims that this strategy, in which the therapist monitors and imitates everything the child does during play, can serve to increase social interest among children with aut-ism. Evidence in support of the effectiveness for this responding technique has been found in experimental studies investigating the effect of brief but focused imitat-ing interventions (Escalona, Field, Nadel, et al., 2002; Field, Field, Sanders, et al., 2001; Heimann, Laberg and Nordøen, 2006). The‘being-imitated strategy’ has also to some extent been included as an integrative part of vari-ous clinical investigations (Ingersoll and Schreibman, 2006; Landa, Holman, O0Neill, et al., 2011; Salt, Sellars, Shemilt, et al., 2001), all of which report an increase in imitation as one of the outcomes. A recent review by Contaldo, Colombi, Narzisi, et al. (2016) provided renewed support for the positive effect of a ‘being-imi-tated strategy’ on measures such as social gazes, proximal social behaviours and play skills. Ingersoll and Dvortcsak (2010) and Killmeyer and Kaczmarek (2019) have devel-oped programmes for parent-implemented models using responsive technics including the ‘being-imitated strat-egy’. IR is usually administered with a high degree of regularity, that is daily sessions 5 days a week at pre-schools, with session lasting 30–40 minutes (e.g., Salt, Sellars, Shemilt, et al., 2001). The following responsive strategies were presented to the participating preschool teachers of this study: (1) face-to-face proximity, (2) imi-tating/mirroring all child behaviours and (3) providing
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temporally contingent responses (Ingersoll, 2013; Inger-soll and Dvortcsak, 2010; Kasari, Gulsrud, Wong, et al., 2010; Nadel, 2000, 2014) with a double sets of toys (Nadel, 2006, 2014).
In this paper, IR will be compared with a behaviourally based comprehensive programme that represents the pre-ferred method (TAU) used by the Health & Habilitation services that provide the treatment of children with ASD in Gothenburg, Sweden. A comprehensive programme is a treatment package that targets all areas deemed impor-tant to be further developed in children with ASD (Vis-mara and Rogers, 2010). The comprehensive programmes for children with ASD are usually based on Applied Behaviour Analysis (ABA; Cooper, Heron and Heward, 2007), often under the acronym IBT (Intensive Behaviour Treatment; see, e.g., Fovel, 2002; Leaf and McEachin, 1999; Lovaas, 2002; Maurice, Green and Luce,1996).
These programmes are all manualised and based on well-known operant and respondent learning approaches (Schreibman, Dawson, Stahmer, et al., 2015). IBT pro-grammes usually employ an imitation strategy with the aim of eliciting an immediate response, especially during the initial phase, even though imitation per se is not the main focus since the programmes have a much broader scope (Leaf and McEachin, 1999; Maurice, Green, and Luce, 1996). IBT is the most frequent intervention used at Swedish Child and Adolescent Habilitation and Health Centers (Eikeseth, Klintwall, Jahr, et al., 2012; Fernell, Hedvall, Westerlund, et al., 2011; Spjut Jansson, Minis-calco, Westerlund, et al., 2016) and it is also the treat-ment of choice at the habilitation centre which is participating in the current study. The standard procedure is for both parents and preschool teachers to carry out their child0s individual exercises included in the daily IBT training of targeted areas (e.g., imitation, communication, verbal and academic skills) under the supervision of certi-fied therapists.
Intervention features, such as intensity and cooperation between parents, preschool teachers and habilitation staff, are crucial factors for the outcome of IBT- and IR-train-ing (Ingersoll and Meyer, 2011). Focused interventions targeting a single skill, for example imitation, usually require shorter implementation and intervention periods and training of co-therapists than is the case with compre-hensive programmes. A comparable implementation of parents as co-therapists is found within the relational-fo-cused intervention programme is reported by Mahoney (2009). They reported a smooth process of implementa-tion, and parents reported a high level of applicability to everyday situations.
In contrast, IBT programmes usually recommend a train-ing intensity of 20 hours or more per week for a mini-mum of 1 year (Eikeseth, Smith, Jahr, et al., 2007;
Ospina, Krebs Saida, Clark, et al., 2008; Remington, Hastings, Kovshoff, et al., 2007; Vismara, Colombi and Rogers, 2009). A meta-analysis by Reichow, Barton, Boyd, et al. (2012) found that overall, ABA-based pro-grammes promote medium-effect gains in several areas, including intellectual functioning, language development and social functioning. The planned training intensity in this study for the focused intervention, IR, was 2.5 hours per week, and for the comprehensive programme, IBT, 25 hours per week.
Strauss, Mancini and Fava (2013) concluded that the effect of IBT programmes increases if both parents and preschool staff are involved in training, which contrasts with more university-based studies that tend to use only specifically trained therapists (Eikeseth, Smith, Jahr, et al., 2007; Lovaas, 1987). The importance of family involvement has also been highlighted in a summary of a broad spectrum of early interventions (Narzisi, Constanza, Umberto, et al., 2014). This is further corroborated by successful interventions reported by Kasari, Lawton, Shih, et al. (2014), Rogers, Vismara and Wagner (2014) and Sanefuji and Ohgami (2013), that all focused on using trained parents and teachers as co-therapists. It might be necessary, as suggested by Stahmer and Pellecchia (2015), to have different strategies when training parents to be co-therapists compared with what is required when training professional therapists.
This study aims to evaluate the effectiveness of a new inter-vention, that is IR in comparison with IBT implemented in local preschools by professionals from habilitation services. Our purpose was to explore whether offering children IR or IBT had an effect on socio-adaptive development, and, if one of the interventions were more effective than the other. The study was conducted during a 12-week intervention period, shortly after the children had received their autism diagnosis. On the basis of previous reports (Heimann, Laberg, and Nordøen, 2006; Nadel, 2000; Salt, Sellars, Shemilt, et al., 2002) we hypothesised that children receiv-ing IR would reveal significant gains in play, interpersonal relations and imitation since both Nadel (2014) and Melt-zoff (2007) have argued that imitation has a prominent role in promoting social development. In comparison, we expected the children receiving IBT to show gains in lan-guage, imitation and interpersonal relations based on pub-lished findings (e.g., Anan, Warner, McGillivary, et al., 2008; Eikeseth, Klintwall, Jahr, et al., 2012; Remington, Hastings, Kovshoff, et al., 2007).
Method
Geographical context
Sweden has a tradition of providing preschool education to children from young age and the fee is regulated by the state. In 2017, 84 per cent of Swedish children aged 1–5 years were enrolled in preschool. In the same year children in the ages of 4–5 years had an attendance of 95
per cent with a frequency of at least 3 days weekly. In 2014, an average preschool group for children over 3 years had 16.9 children, whereas for younger children an average group had 12.6 children, usually encompass-ing children with both typical development and develop-mental delays (SKL, 2018). Children from immigrant families had an enrolment of 79 per cent. The distribution between girls and boys in preschool reflects the gender distribution in the population.
Participants
The sample of this study included every child referred to the Child and Adolescent Habilitation Clinics (CAHC) in Gothenburg, Sweden, between March 2011 and Decem-ber 2012, who met the inclusion criteria of: (1) having a chronological age (CA) of 24–48 months, and (2) a recently confirmed diagnosis of ASD according to DSM-IV-TR (American Psychiatric Association, 2000) (see Table 1).
The exclusion criteria were severe epilepsy, which was deemed to be a potential obstacle to therapy. The final sample comprised 40 children. The neuropsychiatric work-up was comprised of clinically validated instru-ments: The Diagnostic Interview for Social and Commu-nication Disorders (Wing, Leekam, Libby, et al., 2002), Autism Diagnostic Review – Revised (Lord, Rutter and Le Couteur, 1994), Autism Diagnostic Observation Schedule (Lord, Risi, Lambrecht, et al., 2000) and the Social Communication Questionnaire (Rutter, Bailey and Lord, 2003). Every child met the criteria for ASD accord-ing to these instruments.
The participants were randomised in two treatment groups (see Figure 1), one receiving IR and one receiving treat-ment as usual (TAU), that is IBT. Four children dropped out before treatment started, three due to family reasons (2 in the IBT; 1 in IR) and one child because the pre-school stopped participating.
Group characteristics. The IR group consisted of 21 children (4 girls, 17 boys) with a mean CA of 41.6 months (SD= 6.2 months, range 27–49). The average mental age was 19.3 months (SD = 7.3 months, range 3–29) based on a Swedish version of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley, 2005). Most of the children (n = 16) lived with
both parents, whereas five lived in single-parent households. Five children had no siblings, 12 had one sibling and four had two siblings or more. Three children had a sibling with ASD. Ten families were native Swedish speakers. The children in the IR group spent an average of 28 hours (SD = 5.38) per week in the regular preschool system with Swedish speaking staff.
The IBT group consisted of 19 children (4 girls, 15 boys) with a mean CA of 40.1 months (SD 5.8 months, range 30–48), and a mean mental age of 19.6 (SD 9.1 months, range 2–42) as measured with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley, 2005). All children lived with both their parents. Six of the chil-dren had no siblings, nine had one sibling, and four had two siblings or more. Five of the children had a sibling with ASD. Nine families were native Swedish speakers. The average time the children spent at preschool with Swedish speaking staff was 26 hours per week (SD= 6.79; see Table 2).
Procedure
Every child was assessed twice, before treatment started (T1) and after completion of the planned 12-week inter-vention period (T2). When the T1-measurements were finished the randomisation, procedure took place and each parent and preschool teachers were informed about which intervention each child would receive.
The assessment was carried out by experienced clini-cians at the CAHC. Children from non-Swedish speak-ing families were supported by certified interpreters during every stage of the study. The responsible supervi-sor arranged a supervision session with preschool staff and parents. A 2-week long period including informa-tion, a workshop and planning was then completed. Altogether, the planning, preparation and testing period took an average of 5 weeks before intervention started. After the completion of the intervention, at T2, the clini-cians who carried out the follow-up testing were not aware of what treatment group the child belonged to and previous test results. T2-measurements were com-pleted 5 months after the first measure at T1 (see Table 3 for details).
Instrument
Psycho Educational Profile, third edition (PEP-3) and Vineland-II are both instruments that have been consis-tently found to produce valid a reliable data on adaptive and psychoeducational functioning when clinically assess-ing young children. Both scales have been used in their Swedish adaptation.
PEP-3. Three subscales from the Psycho Educational Profile, third edition (PEP-3) (Schopler, Lansing, Reichler, et al., 2005) were used: Expressive Language, Receptive Language and Visuo-Motor Imitation. PEP-3 is designed to provide information that can function as a Table 1: Chronological (CA) and mental age (MA) in
months for the two intervention groups at baseline
Imitation Responding (IR) Intensive Behaviour Treatment (IBT) P M SD Range M SD Range CA 41.6 6.2 27–49 40.1 5.8 30–49 NS MA 19.3 7.3 3–29 19.6 9.1 2–42 NS
basis for formulating individualised training programmes for children with pervasive developmental disorders and related problems. Raw scores produced by the test battery are converted into age equivalents (AEs) in months derived by normative data from an US sample,
Vineland-II. The Vineland Adaptive Behaviour Scales, second edition (VABS-II) (Sparrow, Cicchetti and Balla, 2005) was used when interviewing the preschool teachers about children’s adaptive skills. This standardised interview is designed to assess the child’s adaptive behaviour across four domains: social, communication, daily living and motor skills. Four subscales were used: Expressive Language, Receptive Language, Play and
Interpersonal Relations. Age equivalents in months were derived by normative data from an US sample.
Intervention procedures
Imitation responding (IR). Imitation Responding is a focused intervention based on theories and therapeutic strategies, primarily formulated by Nadel (2000, 2004, 2014). For this study, an adapted Swedish manual was compiled by the main author (Spjut Jansson, 2011). All sessions were performed in a specifically designated room at the preschool, and two identical sets of objects were used, selected with each child’s developmental level and fine motor repertoire in mind. One-third of the toys were
All children < 48 months receiving an ASD diagnosis btw March 2011 –
December 2012 were invited N = 51 Exclusion criteria: treatment resistant epilepsy (n = 1) Accepted invitation (n = 44)
Pretested children offered one of two randomized treatments: Imitation Responding (IR) or Intensive Behavior
Treatment (IBT) n = 44
Dropped out due to private family reasons, n = 3
(IR = 1; IBT = 2)
Preschool not participating, n = 1 (IBT) 40 children.
IR n = 21 IBT n = 19
new to the child to arouse curiosity, one-third were intended to arouse interest in and recognition of familiar objects (e.g., a flashlight and a doll) and one-third were expected to illustrate the child’s level of object manipulation (e.g., balls, cars and blocks). The reason for including familiar toys was to reduce any initial resistance and/or anxiety in the child (Scarpa, Francßois, Gobert, et al., 2013). During the session, the therapist (clinical supervisor or preschool teacher) directly imitated all behaviours exhibited by the child, such as fine-motor and gross-motor movements, gestures, facial expressions, sounds, vocalisation and speech. Behaviours deemed to be harmful or causing injury to the child were not imitated. The purpose of this procedure was to establish
reciprocity by providing the child with an opportunity to demonstrate his or her own communication skills and to learn about the social world (Field, Nadel and Ezell, 2011).
Prior to thefirst session with each child, parents and pre-school teachers attended an information meeting where the ‘being-imitated strategy’ was presented. At a later point in the intervention parents and preschool teachers participated in an individual workshop where they received training from their clinical supervisor.
All participating preschool teachers were filmed for 10– 15 minutes at the start of the intervention to assess treat-ment adherence. They had all been evaluated and assessed by two of the authors (BSJ and TT) as being able to accurately carry out the‘being-imitated strategy’. The planned intensity was a daily 30/40-minute session conducted by the child’s assigned therapist 5 days a week. One of these sessions was conducted jointly with the clinical supervisor (psychologist, special educator or speech and language pathologist) with the intention to monitor treatmentfidelity. In addition, daily protocols and diaries were used to assess treatment fidelity. The ses-sions involving the clinical supervisor were videotaped and then evaluated together with the child’s assigned pre-school teacher/therapist to evaluate progress and increase treatment adherence.
Intensive behaviour treatment (IBT). The IBT intervention is a manualised comprehensive programme with a curriculum based mainly on insights and theories formulated by Applied Behaviour Analysis (ABA; Cooper, Heron, and Heward, 2007). Before the children’s first individual session, each parent and preschool teacher were invited to an information meeting where basic theoretical knowledge was provided in the form of a two-hour lecture that also included filmed material. Later, a training workshop was held, focusing on various specific ABA strategies.
The daily training was supposed to cover at least 6 out of 13 skills, and training in imitation skills was intended to be one of these skills in focus in the daily training during the initial phase of the intervention. Exercises build on ABA strategies such as discrete trial training, incidental teaching, chaining, reinforcement, prompt and prompt fading, all aimed at errorless learning. All training was based on modelling and hands-on applications with the individual child. Written worksheets were given to par-ents and preschool teachers during each session including a plan showing the exercises the child’s training should cover.
Psychologists, special educators, or speech and language pathologists from a specialist team carried out clinical supervision twice a month, focusing on training sessions Table 2: Characteristics of participants at baseline
(T1) in the two groups, Imitation Responding (IR, n = 21) and Intensive Behaviour Treatment (IBT, n = 19) IR IBT N % N % Gender Male 17 81.0 15 78.9 Female 4 19.0 4 21.1 Intellectual disability Mild IQ 51 - 69 5 23.4 6 28.6 Severe IQ< 50 1 4.8 – – Family characteristics
Native Swedish speakers 10 47.6 9 47.4
Parents cohabiting 16 76.2 19 100
Siblings 0–17 years living together (incl. the child in the study)
One child 5 23.8 6 31.6
Two children 12 57.1 9 47.4
Three children or more 4 19.0 4 21.1 Siblings with identified
neurodevelopmental diagnosis
3 14.2 5 1
Time in preschool Mean hours/week/group 28 26
Table 3: Treatment dosage for the two intervention strategies used: Imitation Responding (IR) and Inten-sive Behaviour Treatment (IBT)
IR (n = 21)
IBT (n = 19)
M SD M SD
Length in weeks 10.2 2.1 10.8 1.4
Months between T1 and T2 5.4 1.1 5.1 0.3 No. of therapy sessions with supervisor 9.8 1.9 7.9 3.3 Home training, hours/week 0.4 0.8 10.4 4.6 Preschool training, hours/week 1.81 0.4 3.9 3.8 Total amount of training, hours/week 2.2 1.0 14.4 2.5
when parents and preschool teachers worked together. Each session lasted 1–1.5 hours. Initially, the training was planned to last for 15 hours per child and week dur-ing the start-up phase of this study. The traindur-ing was evaluated after each session with priority given to individ-ual exercises, to determine, for example if reinforcement and prompting techniques were utilised according to the instructions in the manual. Both parents and preschool teachers completed protocols of their daily training with the children, and the protocols were then used for moni-toring implementation. To maintain the consistency of the intervention, changes or clarifications were regularly reviewed and supervised by the first author of this study to shape the intervention.
Ethics
This study was conducted according to guidelines laid down in the Declaration of Helsinki, with written informed consent obtained from a parent or guardian for each child before any assessment or data collection. All procedures involving human subjects in this study were approved by the Regional Ethical Review Board, Gothen-burg (418–10, 2010).
Statistical analysis
Seven separate Split Plot Mixed ANOVAs were used for the overall between-group comparison. Within groups, a comparison analysis using Student’s paired t-test was conducted to analyse change in adaptive and
psychoeducational functioning from the start of the inter-vention to the end. To avoid type 1 errors due to multiple comparisons, Bonferroni correction was used (a = 0.007) even when specific hypotheses were stated.
Results
Treatment intensity
The average intervention length was 10.2 weeks (SD = 2.07, range 7–12, [95% CI 9.3; 11.2]) for the IR group, and 10.8 weeks (SD = 1.4, range 8–12 [95% CI 10.1; 11.5]) for the IBT group (Table 3). No significant difference between the intervention groups was noted for length in weeks. The IR group received treatment for an average of 2.2 hours (SD = 1.0 hour) per week, whereas the IBT group received treatment for 14.4 hours (SD = 2.5 hours) per week.
Between-group comparisons
When analysing whether the change from T1 to T2 (see Tables 4 and 5) differed between the intervention groups, seven separate Split Plot Mixed ANOVAs were calcu-lated with treatment group (two levels) as a between-sub-ject variable, and time (two levels) as a within-subbetween-sub-ject variable. The results showed a main effect of time for all variables on both PEP and Vineland (P< 0.007) but no significant interaction (group x time) for any PEP (Ps range 0.074–0.602) or Vineland variable (Ps range 0.368–0.559).
Table 4: Pre-test and post-test results in age equivalents for PEP-3 – subscales Expressive and Receptive Lan-guage, and Visuo-Motor Imitation – for the two intervention groups: Imitation Responding (n = 21) and Intensive Behaviour Treatment (n = 19)
Area
Imitation responding Intensive behaviour treatment
T1 T2 Within-group comparison T1 T2 Within-group comparison M (SD) M (SD) T Pa ESb M (SD) M (SD) T Pa ESb Expressive Language 14.48 (4.14) 17.10 (5.80) 2.86 0.001 0.52 16.34 (7.08) 21.16 (11.33) 3.47 0.004 0.47 Receptive Language 14.62 (5.30) 16.38 (5.92) 2.48 ns 0.31 15.95 (6.83) 24.74 (15.43) 3.79 0.002 0.74 Visuo-Motor Imitation 22.19 (8.08) 25.90 (8.73) 3.40 0.005 0.44 23.00 (7.65) 27.8 (8.8) 4.02 0.001 0.59 a
Alpha≤ 0.007 due to Bonferroni correction. Exact values but P ≤ 0.001 is listed as P = 0.001.bES= Cohen’s d.
Table 5: Pre-test and post-test results based on age equivalents for VABS – subscales Expressive and Receptive Language, Play and Interpersonal Relations – for the two intervention groups: Imitation Responding (n = 21) and Intensive Behaviour Treatmenta(n = 18)
Area
Imitation responding Intensive behaviour treatment
T1 T2 Within-group comparison T1 T2 Within-group comparison M (SD) M (SD) T Pc ESd M (SD) M (SD) T Pc ESd Expressive Language 14.15 (8.34) 18.50 (9.68) 3.08 0.006 0.48 13.72 (9.63) 22.44 (11.37) 5.17 0.001 0.77 Receptive Language 14.40 (13.27) 18.40 (10.40) 2.35 ns 0.35 16.44 (11.53) 23.33 (14.13) 4.02 0.001 0.51 Play 10.15 (7.11) 15.85 (8.59) 3.08 0.006 0.75 11.28 (9.54) 19.50 (14.03) 2.90 ns 0.59 Interpersonal Relations 9.80 (6.61) 14.20 (7.45) 2.59 ns 0.66 8.61 (13.00) 13.00 (8.94) 2.05 ns 0.45 a
a ≤ 0.007 due to Bonferroni correction. Exact values but P ≤ 0.001 is listed as P = 0.001.b
Within-group comparisons
Paired t-tests were used for within-group comparisons of gains in age equivalents (AE) from T1 to T2 on PEP-3 (Table 4) and VABS-II (Table 5).
Imitation responding. Significant increases from T1 to T2 was noted for PEP-3, Expressive Language with a medium effect size (d = 0.52) and Visuo-Motor Imitation with a small effect size of 0.44. The gain in age equivalents observed for Receptive Language was non-significant (Table 4).
For VABS-II, a significant increase from T1 to T2 was observed for Expressive Language with a small effect size (d = 0.48), and for Play with a medium effect size (d = 0.75). Receptive language and Interpersonal Rela-tions did not increase from T1 to T2.
In summary, our hypotheses for IR were supported for the areas of play and imitation but not for interpersonal relations. The significant effect for expressive language on both VABS and PEP was not expected.
Intensive behaviour treatment. All three PEP-3 measures increased significantly from T1 to T2. Medium effect sizes were noted for Receptive Language (d = 0.74) and Visuo-Motor Imitation (d = 0.59), whereas Expressive Language showed a significant gain with a small effect size (d = 0.47).
On the VABS-II scale significant gains in age equivalents were noted for the two language measures but not for the Play and Interpersonal Relations scales. Medium effect sizes were observed for both Expressive Language (d = 0.77) and Receptive Language (d = 0.51).
The pre-stated hypotheses for IBT were supported for all language measures but not for the area of interpersonal relations. In addition, an increase in imitation as measured by Visuo-Motor Imitation was found.
Treatmentfidelity
Imitation responding. Five preschools out of 21 (24%) reported problems with the way in which IR was implemented. One preschool could not provide a treatment room that was separate from the regular play area, and, due to communication issues. Two preschool teachers had been using instructions instead of verbal imitation when children were able to talk. For two children, a higher frequency of stereotypic behaviour was reported when IR was implemented, thus the number of sessions were fewer than two times a week.
Intensive behaviour treatment. Problems were noted for three children (16%). For two of these children, the parents reported almost no training in the child’s home, and for one child the preschool reported a very low
amount (less than one hour weekly) of hours allocated for training.
Discussion
This study explored the efficacy of IR and IBT as initial interventions for young children with ASD. IR was implemented in local preschools by preschool teachers and professionals from habilitation services, whereas IBT was carried out conjointly by parents and profes-sionals from the habilitation services. The goal was to study the effectiveness of IR compared to an established IBT programme. The overall comparisons of differences in socio-adaptive gains between the two intervention programmes proved to be non-significant. This means that a focused intervention such as IR, which is based on the ‘being-imitated strategy’, was as effective as the comprehensive IBT programme during a brief start-up-intervention.
Several different predictions were formulated at the out-set of the study regarding how the implemented interven-tions would affect the two groups. Based on previous findings (e.g. Heimann, Laberg, and Nordøen, 2006; Nadel, 2000)), gains were expected in the IR group for the subscales of Play, Interpersonal Relations and Visuo-Motor Imitation. The children in the IR group displayed significant changes from T1 to T2 in two of these expected areas, that is Play and Visuo-Motor Imitation. No significant change was found for the subscale of Interpersonal Relations. As expected, Receptive Lan-guage did not show a significant change, whereas in con-trast – and unexpectedly – Expressive Language increased significantly from T1 to T2. This finding needs further investigation. It has been theorised by Nadel that IR-strategies increases the motivation of the child to use language as a tool to entice interest from the adult (Nadel, 2002, 2006). Ingersoll and Schreibman (2006) reported a varied outcome of spontaneous language growth as an effect of IR-training and noted that non-verbal children showed a slow change in response to treatment.
Our findings indicate that the ‘being-imitated strategy’, as employed here though IR, promotes both Play and Imitation as measured with VABS-II and PEP-3. Other studies using the ‘being-imitated strategy’ in clinical interventions have also reported positive effects on chil-dren’s play and social ability (e.g., Ingersoll and Schreibman, 2006; Salt, Sellars, Shemilt, et al., 2002). Both Nadel (2014) and Meltzoff (2007) have argued that imitation has a privileged role in promoting social devel-opment. Nadel (2014) argues that the experience of 0 be-ing imitated0 within an adult–child interaction creates social expectancies or synchronicity that make the social situation salient to the child. The method may help the child to become aware of the relationship between him-self/herself and the therapist’s behaviour and communi-cation.
For the IBT group, growth was expected for both Expres-sive and Receptive language and Visuo-Motor Imitation as measured with the PEP-3 (Eikeseth, 2009; Eikeseth, Klintwall, Jahr, et al., 2012; Eikeseth, Smith, Jahr, et al., 2002; Remington, Hastings, Kovshoff, et al., 2007). The within-group analysis partly supported these expectations but also revealed changes within areas not specifically tar-geted when our hypotheses were formulated. Significant outcomes were found in all three variables measured by PEP-3, Receptive Language, Expressive Language, and Visuo-motor imitation. VABS-II showed significant out-comes on the language scales with a medium effect size. In contrast, the results for the Play and Interpersonal Relations-measures were non-significant, an unexpected finding since the IBT programme is aimed specifically at promoting relational skills.
The efficacy of IBT has previously been evaluated in the context of longer intervention periods, due to the nature of the intervention programme (Reichow, Barton, Boyd, et al., 2012). To our knowledge, only one other study has investigated the effect of IBT after an intervention as brief as the one employed here. Anan, Warner, McGilli-vary, et al. (2008) offered IBT to children below 4 years of age with an intensity of 15 hours per week over a 12-week intervention period, and they reported significant growth. They also reported an increase in both language and social skills, thus corroborating the positive change noted in our study for both the IBT and the IR groups. As already stated, the intervention period was brief, just twelve weeks, which is not the recommended length of time for comprehensive programmes such as the IBT method. Moreover, the intensity was lower than is usually prescribed for IBT programmes, 15 hours per week instead of the recommended 25 hours. However, there is a need to determine already after 12 weeks if treatment should continue with the same intensity of training. Lot-fizadeh, Kazemi, Pompa-Craven, et al. (2018) found mod-erate effects for social skills and language but no gains for adaptive functioning after 15 hours of weekly training over 12 weeks.
In comparison, the IR group received an average of 2.5 hours of training per week, classifying it as a low-in-tensity intervention. Inlow-in-tensity must obviously have a lower limit. Lidstone, Uljarevic, Kanaris, et al. (2014) found that one hour per week over a 12 week-interven-tion had no effect. However, despite these shortcomings we observed positive results that suggest that preschool teachers and parents as co-therapists can provide effective interventions for the child even when the amount of time allocated is limited, as was the case in our study.
Why did the two programmes in this study reveal an almost identical level of outcome? One possible answer is that the study was successful in selecting measures sensitive to development of young children with ASD
for both interventions. Both the IBT and IR group were found to have effect on language skills and social skills even if the IR group increased significantly in play com-pared to the IBT group. Schreibman, Dawson, Stahmer, et al. (2015) stresses the importance of allowing the child to take active parts in therapy. They emphasise the need for interventions to incorporate strategies aimed to encourage affective engagement of participation to learn of social interaction. Schreibmans0 article stresses the role of the social relationships as an essential context for developing imitation and the foundations of commu-nication. This study could report that both IR and IBT have an advantage in helping children develop skills in the context of weekly training. Another possibility is that there is a general effect of being enrolled in the preschool curriculum. Both groups spent on average more than 25 hours per week in regular preschools, which might have promoted similar growth in both groups. However, none of the preschools reported any specific training aimed at children with autism outside of the implemented intervention strategies, IR or IBT, which makes it unlikely that the time spent in pre-schools would be the sole explanation for the observed change over time.
Besides the number of participants and the intervention length, there are several other methodological limitations to an intervention study like this study. The most impor-tant issues regard the validity and reliability of the instru-ments chosen, and fidelity. The decision to use two different instruments, one interview-based (VABS-II) and one test (PEP-3), to measure language was made with the tentative assumption that that this would limit possible floor effects based on the findings in some previous stud-ies (Charman, Baron-Cohen, Swettenham, et al., 2003; Hudry, Leadbitter, Temple, et al., 2010). Nevertheless, floor effects could not be avoided as can be seen in the PEP-3 results.
Finally, any intervention relies on how well treatment fidelity has been achieved. Did the preschool teachers and parents adhere to the principles that define the interven-tion, or did they make adjustments that might interfere with the validity of the data? These possible adjustments could be incremental, almost unnoticeable at first, but as time passes the intervention might deviate more and more from the prescribed path. Several steps were taken to counteract this threat to the treatment fidelity. These included a comprehensive initial workshop, an ongoing supervision session throughout the intervention, video feedback, and checklists. Despite these precautions, cer-tain problems still occurred. Most seriously, five of the 21 preschools (24%) working with IR reported problems with the way the intervention was implemented, e.g. not able to provide a special room for the training sessions or failing to react adequately to the child’s stereotypic beha-viour). Two preschool teachers had been using labelling instead of instructions or verbal imitation when children
were able to talk. The most important factor considering fidelity may be the supervisor’s competence, adherence to the manual, cooperation with preschool staff, and their access to resources, such as flexibility in terms of rooms, toys and staff. When checking for feasibility to maintain adherence throughout the study, we registered compo-nents based on individual adaption of the needs of indi-vidual children, centred on the ‘being-imitated strategy’ as defined by Nadel (2000, 2004) and in the RIT manual (Ingersoll, 2013).
Problems were noted for three out of 19 children in the IBT group. Two families reported completing a lesser amount of training at home, and one preschool reported almost no training taking place. For these three children the programme was sub-optimally implemented. In IBT programmes, strict demands are initially put on parents and preschool staff to follow ABA principles and to carry out an appropriate amount of training hours. This could prove to be problematic and create initial resistance. In line with the intend-to-treat procedure that guided the study, all the children were still included in thefinal anal-ysis regardless of whether they received the intended interventions in full or not.
Strengths and limitations
Several limitations must be considered when interpreting our results. The sample sizes are relatively small and heterogeneous, and the intervention period is brief. Fur-thermore, an initial drop-out of four children affected the randomisation procedure and the two groups were unequal, with 19 and 21 children respectively. There was also a large difference in allocated intervention time between the intervention groups. All children were enrolled at regular preschools during the intervention, and no individual training took place outside the interventions in this study.
However, the study also has certain strengths. Test ses-sions were videotaped, independent scoring was used, and a clinician unknown to the child and parent tested the child at T1 and T2 (the protocols from T1 were not available to the professional carrying out the test at T2). For the VABS measurement, a professional unknown to the parent and preschool teacher conducted the interview. From a clinical perspective, it is an additional advantage that no children were excluded based on IQ or language spoken at home. Studying children with autism and ASD means having groups of children with variations in strengths and difficulties regarding cognitive functioning and language skills, and the heterogeneity in the clinical group cannot be fully controlled by randomising. The use of an established operationalised assessment procedure also increases the validity of the results. A further strength is the control of leakage-effects, with no children in the IBT group receiving IR before participation, and
no children in the IR group having had any prior experi-ence of IBT.
Conclusion
The main overall finding is the positive results obtained for both intervention methods. An intervention such as IR is probably preferable when development in play and expressive language-domains are of extra importance, per-haps as a complement to IBT-training. Other situations when IR could be useful are when resources are low, when preschools are overloaded, or when parents have difficulty allocating 10–15 hours per week to their child’s therapy. A comparable implementation of parents as co-therapists is found within the Relational Focused Inter-vention programme as described by the authors of this study. They reported a non-problematic process of imple-mentation, and parents reported a high level of applicabil-ity to everyday situations.
As in this study, IBT implemented by habilitation clinics with preschool staff and parents as co-therapists influenced language skills. This naturalistic IBT provided the children with training based on individual training plans with the aim of increasing generalisation to everyday situations. The study adds to existing knowledge of possible inter-ventions available for young children with ASD, even if our findings must be considered preliminary. There is a need to further explore possible predictive markers regard-ing individual differences in response profiles and how active elements of different interventions might interact with one another combined. There is also a need for repli-cation studies, as well as long-term evaluations.
Acknowledgments
We would like to thank the parents, children and pre-school teachers who took part in this study. The two Children Habilitation Centers in Gothenburg that invited them to participate, and colleagues at the habilitation clin-ics who performed the training and collection of data. Finally, this paper honors the memory of Professor Tomas Tjus, who throughout the research process has contributed valuable knowledge from his experience of intervention studies with young children.
Funding information
Support was provided to BSJ via grants from Health and Habilitation, Region West Sweden, the Queen Silvia Jubi-lee Fund, Stockholm and Jerringfonden, Stockholm. MH was supported by the European Science Foundation Cooperation in Science and Technology Action (ESF COST Action), BM 1004 Enhancing the Scientific Study of Early Autism (ESSEA).
Conflict of interest
Address for correspondence Birgitta Spjut Janson,
Regional Rehabilitation Centre, Queen Silvia Chil-dren’s Hospital, Box 21062, SE- 418 04 Gothenburg, Sweden.
Email: birgitta.spjut@vgregion.se
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