Intervention Fails to Reduce Autism Symptoms

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http://www.medpagetoday.com/Pediatrics/Autism/20219

Intervention Fails to Reduce Autism Symptoms

By Walsh, Contributing Writer, MedPage Today

Published: May 21, 2010

Reviewed by Zalman S. Agus, MD; Emeritus Professor

University of Pennsylvania School of Medicine.

A social communication intervention for children with autism improved

parent-child interactions but failed to reduce the severity of autism symptoms,

a British randomized trial found.

Children who received the intervention had a reduction in symptom severity of

3.9 points during 13 months, while those who had treatment as usual showed a

reduction of 2.9 points, for a between-group effect size of & #8722;0.24 (95% CI

& #8722;0.59 to 0.11), according to Green, FRCPsych, of the University

of Manchester, and colleagues.

The Preschool Autism Communication Trial (PACT) explored whether children with

autism would respond with enhanced social and communication skills if parents

adapted their interactions to the child's impairments. It was the largest autism

trial of its kind.

" On the basis of our findings, we cannot recommend the addition of this PACT

intervention to treatment as usual for the purpose of reduction in autism

symptoms, " the researchers stated.

" The intervention does, however, significantly alter parent-child dyadic social

communication in ways that are associated with subsequent positive child

outcomes in longitudinal studies of autism, and are likely to be also positive

for parents themselves, " they said.

Small studies, including a randomized pilot trial, have shown benefits for

direct communication interventions, but effects on core autism symptoms have not

been assessed.

To provide a stringent test of a parent-child communication-focused intervention

among young children with core autism, Green and colleagues undertook a

three-center trial that included 152 children between age two years and four

years, 11 months.

Symptoms were evaluated on the Autism Diagnostic Observation Schedule-Generic

(ADOS-G), which is a semi-structured, play-based tool that focuses on social

interaction, language and communication, and repetitive and stereotyped

behaviors.

The PACT intervention consisted of up to 18 clinic sessions with parent, child,

and a therapist, with the goal of increasing parental sensitivity and

responsiveness to the child's communication, aided by strategies such as action

routines with video feedback.

Both the PACT group and the usual care group received various additional

services, including speech and language therapy, psychoeducation, and education

or child care.

Without baseline adjustment, analysis of covariance estimates found a treatment

effect for the intervention of & #8722;1.06 (95% CI & #8722;2.48 to 0.36).

After adjustment for treatment center, age group, sex, verbal and nonverbal

ability, parental education, and socioeconomic status, the treatment effect was

& #8722;1 (95% CI & #8722;2.45 to 0.46).

On secondary endpoints of assessor-rated receptive and expressive language

scores, the effect sizes were small, at 0.07 (95% CI & #8722;1.95 to 2.08) and

& #8722;0.35 (95% CI & #8722;1.85 to 1.16), respectively.

Assessor-rated effect sizes were larger for tests of parent-child interaction

after adjustment for covariates:

•Parental synchrony, 1.22 (95% CI 0.85 to 1.59)

•Child-initiated interactions, 0.41 (95% CI 0.08 to 0.74)

•Parent-child shared attention, 0.33 (95% CI & #8722;0.02 to 0.68)

Parent ratings of language and social communication, in contrast, showed a

strong effect in favor of the PACT intervention:

•Social composite score, 2.28 (95% CI 0.17 to 4.39)

•Receptive communication score, 30.28 (95% CI 6.90 to 53.68)

•Expressive communication score, 21.37 (95% CI & #8722;6.42 to 49.16)

" These represent the targeted proximal outcomes of the parent-training approach,

and their presence has been associated with positive benefits for later social

and communication functioning in independent prospective studies in children

with autism, " they wrote.

However, treatment effect was progressively attenuated downstream, as the

children moved to more generalized settings:

•Parent interaction with child (parental synchrony), 1.22 (95% CI 0.85 to 1.59)

•Child interaction with parent (child initiations), 0.41 (95% CI 0.08 to 0.74)

•Child interaction with assessor (autism symptoms), & #8722;0.24 (95% CI

& #8722;0.59 to 0.11)

•Child in school (adaptive functioning), & #8722;0.19 (95% CI & #8722;0.44 to

0.07)

" Techniques to aid transmission of these gains in parent-child interaction to

adaptive functioning in wider contexts need to be assessed, " they said.

Strengths of the study were its careful design and methodology, as well as its

prespecified outcomes.

Use of the ADOS-G to assess symptoms may have limited the results, however,

because this is primarily a diagnostic tool and may not be sensitive enough for

measuring changes in symptoms.

Developing objective but more sensitive tests remains an important challenge,

according to the researchers.

An accompanying editorial termed the study an " achievement, " that " furthers the

field by setting a new bar for the minimum standards of rigorous methodology

needed in trials that have potentially far-reaching service and policy

implications. "

The heterogeneity of autism poses special challenges for trials and

interventions, observed J. Spence, MD, PhD, and Audrey Thurm, PhD, of the

Pediatrics and Behavioral Neuroscience Branch of the National Institute of

Mental Health in Bethesda, Md.

Aside from variables such as baseline language and cognitive levels, other

factors that must be accounted for include environmental context, concurrent

treatments, comorbid conditions, " and as yet unknown differences in genetics and

neuropathophysiology, " they wrote.

" Ultimately, the challenge is to define subtypes within this disorder. These

definitions might not only have important treatment implications, but also aid

in understanding etiology, " Spence and Thurm said.