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Autism Treatment based on Applied Behavioral
Analysis:
What Does the Current Research Tell Us?
By Richard Irwin (CTFEAT member)
Research has demonstrated that young children with autism can make
dramatic progress in intensive treatment programs based on the
principles of Applied Behavioral Analysis (ABA). In fact, some children
who begin treatment by age 4 and continue treatment for at least two
years progress so much that they become indistinguishable from typical
children their age. The most thorough study of the effectiveness of
behavioral intervention on children with autism was published in 1987 by
Dr. O. Ivar Lovaas of UCLA (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).
The study compared the progress made by three separate groups of
children with autism: one experimental group and two control groups. The
experimental group consisted of 19 children who were given an average of
40 hours per week of one-to-one behavioral intervention for a minimum of
two years. The first control group consisted of 21 children who were
given 10 hours or less per week of behavioral intervention, while the
second control group consisted of 21 children not treated by Lovaas and
his colleagues. A number of the children in the two control groups
received a variety of other interventions as well. All children were
diagnosed as autistic by professionals not associated with the study. In
addition, the three groups of children were shown by a number of
standard test measures to be virtually identical prior to treatment. The
behavioral treatment addressed all the deficits normally associated with
autism spectrum disorders: cognitive, social, behavioral and
communication.
In the end, substantial and measurable differences were seen between the
experimental group and the two control groups. The experimental group
children, as a whole, showed an average gain of 20 IQ points while the
two control groups showed no gain at all. Nine children in the
experimental group (47%) successfully completed regular first grade
without any supports and obtained IQ scores in the average to above
average range. These nine children had an average gain of over 30 IQ
points and by all measures were normal functioning.
Eight of the remaining ten children in the experimental group
demonstrated substantial gains in all areas of development, but were
unable to attend school without any support. They completed first grade
in special education or language-delayed classes. The remaining two
children were placed in classes for autistic or mentally retarded
children..
In contrast, only one child in the two control groups completed regular
first grade and had an IQ score in the average range. Of the children in
the control groups, 53% were placed in classes for autistic or mentally
retarded children, with the rest completing first grade in special
education or language-delayed classes.
Lovaas and his colleagues published a follow-up study (McEachin, J.J,
Smith, T., & Lovaas, O.I. (1993). "Long-term outcome for children with
autism who received early intensive behavioral treatment," American
Journal on Mental Retardation, 4, 359-372) in which they reevaluated the
9 best-outcome children from the original study when they were about 13
years old (These "children" are today, in 1998, an average of 26 years
old since the data for this study was gathered in 1984-1985). In
addition to measuring the IQ of these children at follow-up, two other
tests, the Vineland Adaptive Behavior Scales and the Personality
Inventory for Children, were used to evaluate this group. These tests
are designed to detect any psychological disturbances and to determine
if a child has the behaviors needed to cope with everyday life. All
tests were administered by professionals who did not know the children’s
personal or treatment histories.
The results of the follow-up study demonstrated that the gains made by
these children persisted. Eight of the 9 children continued to succeed
in normal education classes. One child had been placed in special
education classes subsequent to the original study, but one child
originally placed in special education classes had later been moved to
regular education classes. The IQ scores of the 9 best-outcome children
were the same as at the end of the original study. Independent examiners
were given a mixed group of these best outcome children and typical
children to test, using all the measures discussed above. The examiners
were given no information whatsoever on the children being tested. These
"blind" examiners could not distinguish the best-outcome children from
their typical peers on measures of cognitive, academic, social or
adaptive skills.
Dr. Jay Birnbrauer and Dr. David Leach of Murdoch University published
the best effort thus far at replication of the original study by Lovaas
(Birnbrauer, J.S. & Leach, D.J. (1993) "The Murdoch early intervention
program after 2 years," Behaviour Change, 10, 63-74). They found that 4
of 9 children receiving behavioral treatment made significant progress
and were approaching normal levels of functioning, while only 1 of 5
children receiving no behavioral treatment made significant progress.
This study was limited in three ways. First, there was a limited number
of children available for the study. Second, the children receiving
behavioral intervention were only supplied 20 hours of treatment per
week on average as opposed to the 40 hours per week supplied in the
Lovaas study. Last, due to a lack of funding, the study was only able to
continue for two years. Despite all this, the data is consistent with
the results reported in the original Lovaas study.
Criticisms of the UCLA Studies
It is unlikely that any two studies in the field of autism have
generated as much excitement and undergone as much scrutiny as the
original behavioral intervention study published in 1987 and its
follow-up published in 1993. A number of criticisms have been leveled at
these two studies, some of which identify legitimate areas for
improvement in the studies and some of which are no more that
distortions of the truth. The following is a list of commonly seen
criticisms of the Lovaas studies. This list is by no means
comprehensive. It should be pointed out that five experts in the field
of autism wrote commentaries which were published alongside the 1993
article. Each agreed that the 9 best-outcome children appeared to have
made significant gains and that these gains could be attributed to the
behavioral treatment.
Children were not randomly assigned to the experimental and control
groups. This is absolutely true. The suggestion made by critics is that
the experimental group was intentionally loaded with higher functioning
children and all the lower functioning children were placed in the
control group. In fact, distribution between the experimental and
control groups was made solely on the basis of resource availability. If
there were adequate resources to give a child 40 hours per week of
one-to-one behavioral treatment, then the child was assigned to the
experimental group. If these resources were not available at the time of
referral, then the child was assigned to the control group receiving 10
hours or less of behavioral treatment. The children in the second
control group were not assigned to this group by Lovaas and his
colleagues but were part of a group being treated by other
professionals. Lovaas and his colleagues could have assigned these
children on a completely random basis; however, most reputable
institutions consider it unethical to assign to groups in this manner.
Most ethics review boards prefer children to be assigned based on the
availability of treatment. More importantly, the three groups of
children were shown by all test measures to be essentially identical
prior to treatment, eliminating the argument that the study was rigged
for success.
The children in the study were not representative of autistic children
as a whole. Some critics have suggested that the children in the
experimental group had abnormally high IQ scores at intake and were,
therefore, high functioning children who would have done well regardless
of treatment. This is just not true for several reasons. First, a recent
publication comparing treatment programs ("The Effectiveness of Early
Intervention," edited by M. J. Guralnick, (Paul H. Brookes Publishing
Co., 1997)) listed the average IQ scores at intake for eight different
programs, including the UCLA program. The average intake IQ scores
reported for these programs were essentially identical. Second, the
experimental group was shown to be identical to the two control groups
prior to treatment and yet the two control groups did not make any
significant progress. Third, there is no evidence in the literature that
higher functioning children with autism make gains regardless of
treatment.
Lovaas and his colleagues claimed they cured children of autism. Lovaas
and his colleagues demonstrated that it was possible for children with
autism to achieve "normal functioning" through intensive behavioral
treatment. Nowhere in any of the literature published by the Lovaas
group is the claim made that behavioral intervention is a cure for
autism.
The best-outcome group did not achieve "normal functioning." Some
critics have questioned whether the best-outcome group achieved normal
functioning or just attained high functioning status, retaining some
residual features of autism. In the 1993 follow-up study, a battery of
test measures were used to determine cognitive, social, communicative
and behavioral functioning. These test measures were applied to the
best-outcome group as well as to typical children by professionals blind
to the identity or background of the children. These professionals were
unable to detect any evidence of autism.
The 1987 study relied heavily on the use of aversives. Aversives - a
sharp "no" or a light slap on the thigh - were used as part of the
treatment procedure in a few cases where children exhibited high rates
of aggression and self-stimulatory behaviors. New methods, devised by
Lovaas and other researchers, have replaced the use of aversives.
Currently, no reputable program uses aversives.
Other treatment programs are just as effective. A chapter in a recently
published book ("Early Intervention in Autism" by G. Dawson and J.
Osterling, in The Effectiveness of Early Intervention," edited by M. J.
Guralnick, (Paul H. Brookes Publishing Co., 1997)) reviewed eight early
intervention programs for children with autism. Dawson and Osterling
state that "there exists little evidence that the philosophy of the
program is critical for ensuring a positive outcome as long as certain
fundamental program features are present." However, the review is both
misleading and factually incorrect in some instances. Of the eight
programs reviewed, four (including the UCLA program) utilize the same
intensive one-to-one behavioral (discrete trials) intervention used by
Lovaas in his 1987 study, while a majority of the rest use behavioral
intervention in one form or another. These facts were not made clear in
the review. The four programs not using one-to-one behavioral teaching
(LEAP, TEACCH, Colorado Health Sciences and Walden Preschool), have not
published any data comparing outcomes of children in the program to
those in control groups. Comments on the outcomes for these programs, as
reported by Dawson and Osterling, are as follows:
TEACCH. It was reported that 4 year old autistic children gained 15-19
IQ points by 9 years of age. In fact, this gain was seen only by the
most severely retarded autistic children. In the end, their IQ scores
were still in the mentally retarded range. When all of the children
examined were included in the comparison (severely retarded, mildly
retarded and nonretarded), it was found that no gain in IQ was made from
age 4 to age 9. Despite being in existence since 1972, and having
published numerous articles in the field of autism, the faculty at
TEACCH have yet to publish any peer-reviewed research supporting the
effectiveness of their treatment approach. The only evidence offered to
demonstrate the effectiveness of the TEACCH program are the results from
some parent satisfaction surveys.
Colorado Health Science. According to Dawson and Osterling, this program
resulted in the "doubling of developmental rate in several areas." This
increase in developmental rate was determined by using a method known as
prediction analysis. Prediction analysis attempts to determine what
progress is due to treatment and not just the result of normal
maturation. Prior to treatment, a child is tested to determine their
skill levels in areas such as language or cognition. These measured
skill levels are expressed, in months, as the developmental level of the
child. For example, a 40 month old autistic child may be determined to
have language skills equivalent to a 20 month old typical child prior to
treatment.
The developmental level is divided by the child’s actual age to
determine a baseline development rate. In the case given here, the
child’s developmental rate for language is 0.5, the result of dividing
the 20 month developmental level by the child’s actual age of 40 months.
Prediction analysis says that this is the rate of development expected
of an autistic child in the absence of any treatment. At an age of 50
months the child is expected to have language skills equivalent to a 25
month old typical child. This prediction is made by multiplying the
child’s actual age by the development rate (0.5 x 50 months = 25
months).
After a period of treatment, the predicted developmental level is
compared to the measured developmental level. If the measured
developmental level is higher than the predicted developmental level,
then the treatment is considered effective by prediction analysis. If at
an actual age of 50 months the child was determined to have language
skills equivalent to a 30 month old typical child, then the treatment
would be considered effective because the skill level was greater than
that predicted (25 months).
Prediction analysis is not always reliable and is not a rigorous
evaluation of a treatment. In addition, though the children in the
Colorado Health Science program made some progress in the areas of
cognition, language, fine motor skills and social skills, these skills
never came close to reaching age appropriate levels.
LEAP. Children in the LEAP program were described as making
"significant" gains in language, cognitive and motor skills. Like the
Colorado Health Science outcomes, these gains were based on a form of
prediction analysis. It was also claimed that 50% of the LEAP children
go on to placement in "regular education classrooms." However, it is not
clear if these children required any supports in these classes.
Placement in regular education classes can be a misleading statistic as
the children could require extensive supports or none at all (as in the
case of the 9 best-outcome children in the Lovaas study). Some school
districts mandate full inclusion.
Walden Preschool. The Walden program also used school placement (86%) as
fundamental proof of the treatment effectiveness. Walden also observed
that language use tripled after treatment. However, if a child was using
only a few words prior to treatment, this may not be a significant gain.
No measures were taken to show if improvements were made in the areas of
cognitive function, social skills and behavior.
In conclusion, none of these four programs have published treatment
results that come close to matching those achieved by Lovaas and his
colleagues. Most treatments today claim to be effective and to help
autistic children "progress." However, since the basis for these claims
can vary greatly, these treatments must be held to a higher standard.
Parents should ask: What kind of outcomes, supported by peer-reviewed
research, does this treatment produce? The goal should not be "any
progress" but the maximum possible measurable progress that children
with autism can make.
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