A communication-based intervention for nonverbal children with autism: What changes? Who benefits?

Abstract

This article examines the form and function of spontaneous communication and outcome predictors in nonverbal children with autism following classroom-based intervention (Picture Exchange Communication System [PECS] training). 84 children from 15 schools participated in a randomized controlled trial (RCT) of PECS (P. Howlin, R. K. Gordon, G. Pasco, A. Wade, & T. Charman, 2007). They were aged 4-10 years (73 boys). Primary outcome measure was naturalistic observation of communication in the classroom. Multilevel Poisson regression was used to test for intervention effects and outcome predictors. Spontaneous communication using picture cards, speech, or both increased significantly following training (rate ratio [RR] =1.90, 95% CI [1.46, 2.48], p < .001; RR = 1.77, 95% CI [1.35, 2.32], p < .001; RR = 3.74, 95% CI [2.19, 6.37], p < .001, respectively). Spontaneous communication to request objects significantly increased (RR = 2.17, 95% CI [1.75, 2.68], p < .001), but spontaneous requesting for social purposes did not (RR = 1.34, 95% CI [0.83, 2.18], p = .237). Only the effect on spontaneous speech persisted by follow-up (9 months later). Less severe baseline autism symptomatology (lower Autism Diagnosis Observation Schedule [ADOS] score; C. Lord et al., 2000) was associated with greater increase in spontaneous speech (RR = 0.90, 95% CI [0.83, 0.98], p = .011) and less severe baseline expressive language impairment (lower ADOS item A1 score), with larger increases in spontaneous use of speech and pictures together (RR = 0.62, 95% CI [0.44, 0.88], p = .008). Overall, PECS appeared to enhance children's spontaneous communication for instrumental requesting using pictures, speech, or a combination of both. Some effects of training were moderated by baseline factors. For example, PECS appears to have increased spontaneous speech in children who could talk a little at baseline.