© Mike Connor 2006.
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These notes represent a summary of two further sources of information and observation.
Firstly, conference presentations at ABA Ireland and, secondly, a paper describing a replication of a longitudinal study of ABA intervention with two matched groups differing in the level of intensity of input and frequency of supervision.
The common conclusions highlight
the benefits of the ABA approach for some, but not all, young children with
autism; and there is reference made to variables which appear to have
predictive validity in determining which children will make rapid and positive
progress and those whose progress will be limited.
Summaries of presentations made
by Gina Green and by Jane Howard in respect of the current state of play with
regard to ABA were made available to the present writer (MJC) and are helpful
in highlighting both the benefits for many young autistic children of this
approach and some continuing questions and reservations.
Gina Green describes how the
essence of ABA is a careful observation, recording, and analysis of behaviour,
adapted from the initial work of Skinner, which seeks to develop skills and to
reduce maladaptive behaviours in individuals with and without
disabilities.
The emphasis is upon positive
reinforcement by which to increase the probability of occurrence of certain
behaviours.
Component teaching involves the
breaking down of skills into small steps which can be specified and observed
and measured, and “Discrete Trial Training” is used to teach these component
elements through an ABC approach … antecedent, behavioural response,
consequence, with adult cues and prompts by which gradually to shape the
behaviour as required and which can be faded over time.
A close structure is seen as
important, albeit within the child’s natural situation of home or nursery, and
minimal time is left without direct attention and stimulation directed towards
the child in order to avoid opportunities for the practice of interfering and
characteristically-autistic behaviours.
Any maladaptive behaviours are
not subject to any reinforcement, and the goal is to replace such behaviours
with acceptable responses via the task analysis and the systematic/selective
reinforcers.
The quantity of empirical
evidence is noted, demonstrating the effectiveness of this kind of approach for
many young children with autism.
However, not all children show
positive progress, and the present writer - MJC - remembers both the advice of
Lovaas himself to the effect that the procedures are intensive and potentially
very challenging for both child and teachers or parents with the implication
that one should not pursue such a course unless there is growing confidence in
its likely effectiveness; and the findings set out in the series of papers from
Reed et al (University of Wales, Swansea) which have indicated that ABA is not
always appropriate (with higher levels of existing parental stress as a clear
contra-indicator).
This being so, there continues to
be a particular interest in defining those characteristics of the children and
of their familial environment which appear to be consistently associated with a
higher probability of positive outcomes, in terms of significant developmental
progress, from the implementation of an (intensive) ABA programme.
Green has reviewed a range of
studies and suggest that successful programmes seem to be those which :
Green concluded that early and
intensive ABA can lead to large improvements in multiple areas of functioning
for many children, but that …..
The presentation by Jane Howard
focused upon her own recent study which compared the use of an intensive
ABA-type intervention with a set of “eclectic” approaches among samples of
young children with autism.
Her introduction also indicated
that a common goal among interventions is the closing of gaps in the
developmental trajectories of the children in question compared with their
normally-functioning peers, but that there are a number of unknowns in this
field.
For example, she refers to the
lack of ability to predict what progress can or will be made in response to the
timing or type or intensity or duration of ABA intervention; nor is there very
much information from direct and methodologically-valid comparisons of defined
interventions such as ABA vs. TEACCH.
The study that Howard completed
with her team compared 3 groups of children … those receiving a generic early
years’ programme operating for about 15-17 hours each week in a small group involving
access to speech therapy and a range of early years activities; an
autism-specific class operating for up to 30 hours each week and allowing some individual working and
access to speech therapy, and elements of PECS, TEACCH, DTT, and circle time; and
an intensive ABA group involving individual working up to 35 hours per week
with the targets of enhanced imitation and attention, etc.
It is acknowledged that the
children were not randomly assigned but that parental preference was the
determining factor.
All the children were below the
age of 48 months (the ABA group younger still) and all had a clear diagnosis of
autism with no secondary medical complications.
After one year of intervention,
the ABA group was shown to have made the greatest improvements in the areas
assessed.
It was held that the issue was
not simply the number of hours (intensity) and evidence was cited from an
existing study to the effect that comparisons of children receiving a similar
intensity of ABA and of an eclectic combination of approaches showed the
greater benefits of the ABA working.
Her own hypotheses are that the
children in question do benefit from a targeted and specific type of
intervention (and this would fit to the common finding of the difficulty among
children with autism in shifting attention especially when the shift is not
just from one task to another but when there is a shift in the type of task and
the necessary use of different skills or sensory modalities).
The combination of eclectic
components do not so readily fit the style of the children in question, and the
“jack of all trades ” programme does not provide sufficient focus or continuity
or intensity of any one approach.
She also ponders whether the
eclectic approach remains popular because there is no guaranteed success of any
one intervention so that there is a kind of hedging of bets, and a hope or
belief that a combination of approaches will include something to which
there will be a positive response.
Gina Green then offered further
thoughts to highlight the critical need for evidence-based practice by which to
offer some protection to both providers and consumers.
This will involve the need for
the close monitoring of interventions, both in terms of positive and negative
outcomes, such that one can avoid unwarranted claims and questionable marketing
while also gaining some confidence that the investment in time or financing
will be legitimate.
The availability of a valid
choice of interventions, with their clearly delineated benefits and costs, would
also be reassuring for parents as well as logical in seeking to match the range
of needs.
What is needed, she argues, is a
kind of protocol where a panel of experts from a range of related disciplines
can evaluate performance data while ensuring that the evidence is based upon
properly implemented and controlled methodology ….. including information about
dependent and independent variables, the research design, controls, selection
of participants and their allocation to conditions, treatment effects, and
generalising of skills across settings and time.
Outcomes
and Predictors
One can now turn to a study which
has offered at least a partial replication of the original Lovaas research
findings in highlighting markedly positive benefits for many of the children
participating in a controlled study of the effects of ABA under different
conditions.
The paper by Sallows and Graupner
(2005) begins with a review of the various studies, beginning with the Lovaas findings of 1987, which have
demonstrated that intensive behavioural intervention can bring about dramatic
improvements for a significant proportion of children.
However, they also recognise the
methodological criticisms that were directed towards that initial 1987 paper in
terms of the use of the term “recovery” to describe children whose measured
ability fell into the average range and who were being educated within
mainstream schools (when children with higher functioning autism could well
achieve such outcomes via other interventions and that a follow-up of some of
the recovered children at age 13 revealed a continuation of significant
behavioural issues).
Questions were also raised about
the use of aversives within the methods adopted which would no longer be deemed
acceptable.
Importantly, Sallows and Graupner
note that only about half of the children in the Lovaas target sample showed
marked gains, and they highlight the ongoing need to identify features which
will act as predictors of outcomes thus to clarify which children are likely to
benefit from the ABA-type approach.
With regard to aversives, these
authors refer to a number of studies, such as Smith et al (2000), where partial
replication of the Lovaas findings have been sought without the use of
aversives and where most have found that some children showed marked
improvements in IQ.
Fewer children reached an average
level of functioning, but this was attributed to differences in methodology
such as lower intensity and duration of intervention, different sample
characteristics, and less training and supervision for the staff.
(The point about sample
characteristics implies again the logic of seeking to specify what is as about
the child or the circumstances which would predict the greater probability of
positive outcomes to an ABA approach.
In this regard, one notes that the Smith et al study sample is said to
have included an unusually high number of children who had no expressive
language with the reasonable implication that it is the child with the
relatively greater level of language skill at the time of initiating the
intervention who is likely to respond more positively.)
The authors also refer to the
results of behavioural intervention provided by staff working outside
university settings in largely parent-managed treatment with the supervision of
a consultant who is less frequently available than is typical for programmes
completed within a recognised treatment centre.
One such study is that of
Sheinkopf and Siegel (1998) who described results for children who received
around 19 hours of treatment per week over a 16 month period.
6 of 11 children had achieved an
IQ in the average range and 5 of them were in regular classes albeit showing
residual behavioural needs.
However, it was argued that the
sample of children was not comparable to high achievers noted in other studies
because the cognitive measures used included the Merrill-Palmer Test which is
geared towards non-verbal skills and may yield scores higher than those of more
balanced tests which reflect both verbal and non-verbal skills.
(Another possible implication is
that the child with the greater probability of positive outcomes is the one who
is the relatively higher scorer on initial tests of ability which reflect
verbal as much as non-verbal capacities.)
A further study quoted is that of
Bibby et al (2002) who reported results for children receiving an average of 30
hours of parent-managed treatment (range 14 – 40 hours) over a 32 month
period.
10 of 66 children achieved an IQ
in the average range and 4 were attending mainstream classes, but the less
positive outcomes were attributed to the significant minority with a
pre-intervention score of below 37, to the fact that more than half the sample
were older than 48 months at the start, many received less than 20 hours per
week, and the trainers were less experienced than university-based staff and
did not achieve a level of at least weekly supervision of the people directly
implementing the intervention.
(Again, an implication about
predictor variables can be identified in terms of age of child and relative
[measured] ability at the time of the start of the programme.)
Sallows and Graupner summarise
the findings from a number of studies which have included references to
pre-treatment variables and, while acknowledging some lack of consistency, they
suggest that the most commonly observed predictors of outcomes include :
The use of multiple regression
techniques has been used in seeking to determine which combinations of
pre-treatment variables have the greatest association with outcomes. Verbal imitation skill plus IQ plus age appear
the combination most highly correlated with results.
Meanwhile, rapid learning
during the first 3 or 4 months of treatment has been associated with
eventually positive outcome; as has rapid acquisition of verbal imitation plus
non-verbal imitation plus receptiveness to instruction (as reflected in later
re-administration of the CARS and the Vineland measures).
The study by Sallows and Graupner
themselves set out to determine if a community-based programme and one without
aversives can achieve positive outcomes similar to those cited in the Lovaas
data; whether significant residual symptoms remain despite average
post-treatment scores; and whether pre-treatment variables can be identified as
accurate predictors of the outcomes.
The children were recruited from
special educational settings with the criteria of age at entry between 24 and
42 months, a mental age index (mental age divided by chronological age) giving
a figure of at least 35, within normal neurological limits, and a formal
diagnosis of autism from a experienced practitioner with a match to the
guidelines of DSM-IV and the Autism Diagnostic Interview.
13 children began the programme
in 1996, 11 in 1997, and 14 in 1998-1999.
23 of the children (19 boys and 5 girls) had completed 4 years of
intervention or had “graduated” earlier at the time of the report written by
the current authors. Children were
matched on pre-treatment IQ and assigned randomly to a clinic-directed group
(similar to the Lovaas target
group in receiving 40 hours per week of treatment) or a parent-directed group
intended as a less intensive intervention
(around 32 hours with the parents receiving 6 hours per month of
supervision plus a consultation every 2 months with a senior clinician).
The average age at pre-test was
33 months, and 35 to 37 months was the typical age when intervention began.
The measures used included the
Bayley Scales of Infant Development, Merrill-Palmer for a measure of non-verbal
IQ, Reynell Language Scales, and subtests of the Vineland Adaptive Behaviour
Scales. Follow up testing was
implemented annually for 4 years with age appropriate tests coming into use,
such as the WPPSI or WISC-III, and the Leiter Scale, alongside those used at
pre-treatment testing where still appropriate.
Social functioning post-treatment
was assessed by the Autism Diagnostic Interview Revised, and the Personality
Inventory for Children.
At age 7, the children were rated
by parents and teachers on the Child Behaviour Checklist, and achievements were
measured by the Woodcock-Johnson tests.
One further and idiosyncratic
measure was used, namely the Early Learning Measure developed at the University
College of Los Angeles and designed to assess the rate of acquisition of skills
during the first few months of treatment.
Every 3 weeks during the 3 months
leading to the start of treatment and for 6 months afterwards, the same list of
40 items known only to the experimenter (involving verbal and non-verbal
imitation, following verbal instructions, and expressive object labelling) was
used. The measures derived indicated
the number of correct items achieved before the start of the programme, and the
number of weeks required for the child to achieve 90% of the verbal imitation
items as a reflection of rate of progress.
The overall results summarised by
the authors demonstrated that the Lovaas-style early behavioural treatment
could be implemented in a clinical setting outside a university and that
favourable outcomes could be achieved without the use of aversives.
Following between 2 and 4 years
of treatment, 11 of 23 children achieved full IQs in the average range as well
as increases in language and adaptive behaviours. At age 7, these children were working successfully in mainstream
classes showing average attainments, adequate language, and regular play
interaction with peers.
Parent-directed children did
largely as well as those in the first group despite the lower intensity and
less supervision and advice available to the adults.
This finding was described as
unexpected, and it was hypothesised that it was a matter of the parents taking
on the senior therapist role, filling gaps in
the day to day input, and involving neighbours and others to provide the
consistency of attention to, and play with, the children. Further, it was held that the parents may
have experienced problems reflected in the slow progress or non-compliance of
their children by trying to push their children too far or too fast or using
inappropriate interventions, but were able to gain advice without delay and to
avoid repeating the circumstances such that their own skills advanced rapidly.
Meanwhile, it was recognised
that, while not severe or of clinical significance, some residual symptoms of
autism were observed, especially among those children who achieved the average
IQ rating only after several years of treatment.
Among the more rapid learners,
around a third were observed to have mild delays in social skills. “Appearing preoccupied” was also a common
problem for which 3 children were allocated classroom aides to provide
reminders about staying on task.
With regard to predicting
outcomes, the strongest pre-treatment features were the levels of …..
Also strong predictors were the rapid
acquisition of new material as measured by the Early Learning Measure, and change
in IQ after 1 year.
The authors refer to a model
which appears to have the potential for predicting which children will prove
the rapid learners … one of whose components is that of pre-treatment verbal
imitation … but further validation studies are required.
One likely problem with the model
is the limitation in discriminatory power among children above a certain age
level, not yet clarified, given that children often acquire imitation skills by
school age.
The comparability of the Bayley
Test with the Wechsler Test was demonstrated by the authors such that the
switch from the Bayley at initial assessment to the WPPSI at subsequent
assessment was not seen as a confounding factor.
In addition, there was raised the
question whether the positive findings among the rapid learning group could be
due to maturation as much as to the actual input; but the maturation hypothesis
was thought to be discountable in the light of the negligible improvement of
children receiving (non-intensive) community services observed in a number of
longitudinal studies …. such as that of Eikeseth et al (2002).
The authors do acknowledge some
methodological issues including the small numbers of children involved, and the
number of tests used, with the risk of some spurious findings and some question
over drawing implications for a wider population of children with autism.
Two further findings were
highlighted by the authors.
Firstly, the ratings of parental
involvement were only weakly related to outcomes suggesting that more specific
efforts to increase parental feelings of competence and self-belief in being
able to contribute to treatment planning could enhance effects.
Secondly, the acquisition of
social skills was positively associated with the amount and duration of
supervised play, and it may be that variation in the relevant scores among the
children reflected the variation in parental opportunities or willingness to
arrange play sessions with the children of neighbouring families …. although it
was hoped that disadvantages in this one aspect of social skill learning could
be compensated by further experience of alternative stimuli such as video
modelling.
The authors noted that their
study is unusual in approaching the level of input for the clinical group that
was available in the initial Lovaas study, but they still conclude that high
hours and intensive supervision were not sufficient to make up for low levels
of pre-treatment skills.
Instead, they hold that,
consistent with existing studies, low IQ scores (below 44) and absence of
language (no words at 36 months) predicted limited progress; while rate of
learning, imitation, and social relatedness predicted favourable outcomes.
* * * * * *
Bibby P., Eikeseth S., Martin N., Mudford O., and Reeves D. 2002 Progress and outcomes for children with autism receiving parent-managed intensive interventions. Research in Developmental Disabilities 23 81-104
Eikeseth S., Smith T., Jahr E., and Eldevik S. 2002 Intensive treatment at school for 4- to 7-year old children with autism. Behaviour Modification 26 49-68
Green G. 2005 / Howard J. 2005 Presentations to the conference “ Facing Autism : ABA Ireland ” Coleraine , University of Ulster. 16-17 December
Howard J., Sparkman C., Cohen H., Green G., and Stanislaw H. 2005 A comparison of intensive behaviour analytic and eclectic treatments for young children with autism. Research in Developmental Disabilities 26 359-383
Lovaas O. 1987 Behavioural treatment and normal educational and intellectual functioning in young autistic children. Journal of Consulting and Clinical Psychology 55 3-9
Sallows G. and Graupner T. 2005 Intensive behavioural treatment for children with autism. American Journal on Mental Retardation 110(6) 417-438
Sheinkopf S. and Siegel B. 1998 Home-based behavioural treatment of young children with autism. Journal of Autism and Developmental Disorders 28 15-23
Smith T., Groen A., and Wynn
J. 2000 Randomised trial of
intensive early intervention for children with pervasive developmental
disorder. American Journal on Mental
Retardation 105 269-285
© Mike Connor 2006.
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