Outcomes in the Ontario IBI Program

Adrienne Perry, Anne Cummings, Jennifer Dunn Geier, Susan Hughes, Nancy Freeman, Louise LaRose, Tom Managhan, Jo-Ann Reitzel, Janis Williams.

This is a summary of a symposium presented at the ONTABA Conference November 10, 2006, based on a report commissioned by the Ministry of Children and Youth Services (MCYS) submitted by Adrienne Perry, PhD., C.Psych., BCBA. However, the views expressed here are those of the authors and not necessarily those of MCYS.

Intensive Behavioural Intervention (IBI) is a specialized form of intervention designed for young children with autism, based on the principles of Applied Behaviour Analysis (ABA). IBI is considered “best practice” for young children with autism, based on literature which has demonstrated its efficacy relative to less intensive intervention, eclectic intervention, and equivalent amounts of special education. IBI has been publicly funded in Ontario since 2000 through MCYS, via contracts with service providers in each region. Service may be delivered via the public program or by private providers and may take place in a variety of settings (homes, centres, child cares, etc.).

The purpose of this study was to examine children's outcomes in the Ontario IBI Program. It was a study of the "effectiveness" of IBI under "real-world" conditions, as opposed to an "efficacy" study like those from small, model programs in the literature. It was a retrospective file review study, designed to address two main questions: 1. Do children show significant improvement during their participation in the IBI program? (how much improvement, improvement in what respects? e.g., autism symptoms, developmental skills, etc.) and 2. What factors predict greater improvement? (level of functioning, program variables, etc.).

The data used in the study came from 332 files of children (80% boys) in the Ontario IBI program, which is a very large sample size, although it is only a subset of children receiving service in the Ontario program. Available data from intake and exit assessments (diagnostic and developmental measures) were used together with program variables such as age and duration. Measures included the Childhood Autism Rating Scale (CARS), which is a standard observational measure often used in psychological/diagnostic assessments, measuring severity of autism symptoms; the Vineland Scales of Adaptive Behavior, which is a parent interview measure regarding everyday skills in several domains of development (communication, self-help, social, and motor skills); and a cognitive or intellectual test administered to the child (various tests depending on the child’s age and ability level).

Children were between 20 and 86 months old at intake,with 32% under 4 years of age, 34% between 4 and 5 years, 28% between 5 and 6 years, and 6% over 6 years at program entry. The average age was about 4½ years. The duration of IBI received ranged from 4 months to 4 years with an average of 18 months. The children had substantial developmental delays as well as autism. Although there was considerable variability among children, they were functioning, on average, at a 2-year cognitive level and in the moderate to severe range of intellectual disability at intake. Similarly, adaptive levels were in the moderately delayed range with age equivalents below a 2-year level, on average. However, there was a range of ability levels and so children were divided into 3 subgroups based on their initial level of functioning ("higher", medium, and lower) based on Vineland standard scores. (Note that "higher" is a relative term and does not mean high functioning as in average intelligence.)


Results for Question 1. Do Children Improve?

Autism Symptom Severity. Children showed statistically significant and clinically significant reduction in autism symptom severity (CARS Total score). That is, children had less repetitive behaviour, related better to people, had better verbal and nonverbal comunication skills, and improved imitation abilities, etc. at the time of exit compared to their initial scores. About half the children changed enough to fall into a milder category on this instrument. Of those who were in the mild/moderate autism range at intake, 41% improved so that they were in the non-autism range at exit. Of those in the severe autism range at intake, 59% improved to the mild/moderate range and 15% improved very substantially to the non-autism range. Note, however, that these children could still have shown developmental delays.

Cognitive and Adaptive Behaviour Level. Cognitive level (IQ and Mental Age) based on various cognitive tests, improved significantly for children, in some cases dramatically so (but this was unavailable for many children). Further, children gained significantly in developmental skills (increased age equivalents) in all areas of adaptive behaviour (communication skills, self-help skills, social skills, and motor skills) as measured by the Vineland parent interview measure. Standard scores, which are corrected for age, also increased significantly for Communication and Socialization, two key areas of difficulty for children with autism.

Rate of Development. As noted above, children were quite variable but, on average, were substantially delayed developmentally prior to the program. In fact, they had been developing at about one-third of the rate of a typically developing child. Children's rate of development (based on the Vineland age equivalent scores) during IBI was approximately double their rate prior to IBI, and this was true for all three initial subgroups, i.e., even the lower functioning children doubled their rate of development, as a group. This suggests that the developmental trajectory of children was altered during their participation in the IBI program. Many children were even developing at a typical rate (although they may not have "caught up" to typical peers).

Range of Progress/Outcome. There was considerable heterogeneity in outcome, as would be expected given the population. Children were classified into seven categories of progress/outcome based on a combination of all the information available (rate of development, Vineland scores, cognitive scores, and CARS scores). The categories were: Average Functioning, Substantially Improved, Clinically Significantly Improved, Less Autistic, Minimally Improved, No Change, and Worse. The majority of children (75%) showed some measurable benefit or improvement during IBI (i.e., the first 5 categories combined). This included some children who achieved average functioning (average cognitive and/or adaptive levels and non-autism range on CARS), similar to those described as "best outcome" in the efficacy literature). The other 25% did not seem to show improvement (the last two categories combined) at least on the available measures. However, anecdotal evidence suggests that some of these children may have improved in problem behaviour, which would not be captured by these measures.


Results for Question 2. Predictors of Progress/Outcome

Initial Level of Functioning. Children's progress/outcome was clearly related to their initial functioning levels, on average, though not totally. As a group, children who were in the relatively "higher" functioning subgroup initially showed better outcomes, but not in every case. Children who were initially medium functioning were, at exit, to be found in every one of the seven progress/outcome categories, including average functioning. Children who were initially lower functioning also showed a range of progress, though none achieved average functioning.

Program Variables: Age and Duration. Children who started IBI before age 4 did better than those who started after age 4 on all scores on the exit assessment. Children who received 2 years or longer duration of IBI did better than those who received a shorter duration (however, these children were also younger when they entered). Statistical analyses attempting to prioritize the degree of influence of initial level of functioning, age, and duration, showed that initial levels are the strongest determinant, but that they do not account for all the variability (half at most). Age at entry appears to be more predictive than duration of IBI. However, there are clearly other factors (e.g., quality and quantity of intervention, other child factors not measured here) which may account for the unexplained variance.

Strengths and Limitations

There are both strengths and limitations of this study (as with any study). The primary limitation is that the study has no Comparison group, which means gains cannot be conclusively attributed to the IBI program, per se, although the examination of subgroups within the sample partially compensates for this. Also there is no measure of treatment quantity, quality, or fidelity. The principal strength is that the study is the largest (and one of the only) studies which demonstrates the effectiveness of IBI in a large and diverse community sample.