Predictors of reliable symptom change: Secondary analysis of the Preschool Autism Communication Trial

Abstract

Background and aims: Despite recent gains in the amount and quality of early autism intervention research, identifying what works for whom remains an ongoing challenge. Exploiting data from the Preschool Autism Communication Trial (PACT), we undertook secondary analysis to explore prognostic indicators and predictors of response to one year of PACT therapy versus treatment as usual within this large and rigorously characterised cohort recruited across three UK trial sites. Methods: In this secondary analysis of variability in child gains on the primary trial outcome measure-social-communication symptom severity-we used a pragmatic and data-driven approach to identify a subgroup of children who showed reliable improvement and a subgroup showing clear lack thereof. We then tested which among several baseline child and family factors-including measures routinely collected in research trials and clinical practice-varied as a function of child outcome status and treatment group. Results: Greater baseline child non-verbal ability was a significant prognostic indicator of symptom reduction over time (i.e. irrespective of treatment group). By contrast, parent synchrony presented as marginal predictor, and trial recruitment site as a significant predictor, of differential outcome by treatment group. Specifically, lower parent synchrony showed some association with poorer outcomes for children from families assigned to treatment as usual (but with no such effect for those assigned to PACT). Similarly, children at one recruitment site were more likely to have poorer outcomes if assigned to treatment as usual, compared to children at the same site assigned to PACT.

Parent perceptions of participation in a parent-mediated communication-focussed intervention with their young child with autism spectrum disorder

“… e Therapeutic alliance measured by the ‘PACT Alliance Questionnaire’ ( Taylor, 2015 ; Taylor et al, 2017 ), a parent-rated questionnaire assessing the parents’ quality of engagement with the therapy and therapist (low score = high alliance; range within full trial sample: 20–44). f Child response to therapy, categorised using the Reliable Change Index (RCI) of changes between trial baseline and endpoint on the Autism Diagnostic Observation Schedule-Generic ( Lord et al, 2000 ) algorithm total scores; methodology detailed in Hudry et al, 2018 ; RCI categorization within full therapy sample: 35% improvers, 39% intermediate, 26% non-improvers ( Hudry et al, 2018 ). …”

“… f Child response to therapy, categorised using the Reliable Change Index (RCI) of changes between trial baseline and endpoint on the Autism Diagnostic Observation Schedule-Generic ( Lord et al, 2000 ) algorithm total scores; methodology detailed in Hudry et al, 2018 ; RCI categorization within full therapy sample: 35% improvers, 39% intermediate, 26% non-improvers ( Hudry et al, 2018 ). …”

Trajectories of Autism Symptom Severity Change During Early Childhood

“…Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and social interaction, as well as restricted and repetitive behaviors (American Psychiatric Association 2013 ) and affects 1 out of every 59 children (Baio et al 2018 ) in the United States. While the symptoms of ASD are commonly considered to be stable throughout life (Bieleninik et al 2017 ), increasing evidence indicates that at least some individuals demonstrate substantial changes in the core features of ASD and/or comorbid conditions over time (Shattuck et al 2007 ; Georgiades et al 2014 ; Steinhausen et al 2016 ; Hudry et al 2018 ; Solomon et al 2018 ). One example of substantial change is optimal outcome, defined as a decrease in autism symptoms in individuals previously diagnosed with ASD, so that they no longer meet diagnostic criteria (Fein et al 2013 ).…”

Integrating the Early Start Denver Model into Israeli community autism spectrum disorder preschools: Effectiveness and treatment response predictors

“…In the past decade, early intervention research has started focusing on the examination of “what works for whom,” aiming to identify child factors associated with change occurring during intervention. Some of the pre-treatment child-related predictors associated with better response to early intervention include pre-treatment higher cognitive abilities ( Hudry et al, 2018 ; Smith et al, 2015 ; Tiura et al, 2017 ), expression of positive affect ( Fossum et al, 2017 ), decreased social avoidance ( Fossum et al, 2017 ), lower ASD symptom severity ( Ben-Itzchak & Zachor, 2011 ), younger age ( Smith et al, 2015 ; Vivanti et al, 2016 , 2018 ), higher adaptive skills ( Flanagan et al, 2012 ), imitation, functional use of objects and goal understanding ( Vivanti et al, 2013 ), play skills ( Ingersoll, 2010 ), and joint attention ( Kasari et al, 2008 ). The exploration of factors associated with intervention response is essential in community-based treatment programming, where resources are usually limited, the profiles of treated children are heterogeneous, and different intervention options might exist.…”