20211
Meta-Analysis of Community-Based Early Intervention Programs for Children with Autism Spectrum Disorders
Careful measurement of interventions delivered in community settings is an important component of developing effective and sustainable programs. Part of the rationale of measuring community-based intervention is to identify intervention characteristics that are associated with improved child outcomes. Recent results from early intervention trials suggest significant variability in the extent to which children with ASD make gains in community-based early intervention programs. For example, children in some community preschool programs make equivalent gains to children in university-developed programs (Boyd et al., 2013), while children in other programs make much smaller gains (Magiati et al., 2007). To date, however, results from community-based early intervention programs and usual practices have not been examined systematically. Estimating the variability in and predictors of outcomes from published reports of community early intervention programs offers a first step to identifying active ingredients that are potentially effective in community settings.
Objectives:
To calculate the average effects and predictors of cognitive, adaptive behavior, communication, and social outcomes among children receiving community-based early intervention.
Methods:
Studies of community-based early intervention for children with autism were identified through a systematic search of online databases (PsycInfo, Medline, Eric, and Proquest dissertation), hand-searching relevant journals, and reviewing citations from previous meta-analyses and systematic reviews. Community-based early intervention was defined either as “treatment as usual” control groups in randomized or quasi-experimental trials or in studies that explicitly examined outcome in community settings. Changes in cognitive, adaptive behavior, communication, and social functioning from pre-treatment to post-treatment were assessed using standardized mean gain scores. Effect sizes (Hedges’ g) were calculated by dividing the mean change from pre to post-treatment by the pooled standard deviation of the difference score. Overall effect sizes were estimated using random effects models. The Q-statistic and the I2index were used to examine heterogeneity of effect sizes. Potential moderators included type of intervention, geographic location of intervention, year of intervention, sample section methods, sociodemographic characteristics of participants, and length of intervention; their effects were assessed using analysis of variance of mixed-effects models and meta-regression analyses.
Results:
Analysis, especially of moderators, is ongoing. Preliminary results based on 22 studies showed an average effect size of 0.2 (95% CI 0.1 -0.3), 0.5 (95% CI 0.3-0.8), 0.4 (95% CI 0.3 -0.6), and 0.4 (95% CI 0.2-0.5) for cognitive, adaptive behavior, communication, and social outcomes respectively. Hedges’ gs for individual studies ranged from 0.0-0.7 for cognitive outcomes, 0.1-1.3 for adaptive behavior outcomes, 0.0-1.1 for communication outcomes, 0.0-0.9 for social outcomes. Significant heterogeneity across studies was identified for adaptive behavior, communication, and social outcomes.
Conclusions:
Children receiving community-based early intervention make small to medium sized gains on average. The heterogeneity in outcomes suggests significant variation in program quality. Examination of intervention features associated with more effective community-based early intervention programs could offer insight into program features that may be important to consider in the implementation of other community-based programs.