Exploring the effectiveness of the Pragmatic Intervention Programme (PICP) with children with autism spectrum disorder and developmental language disorder: A non-randomised controlled trial

Using language for social purposes can be a real challenge for children with autism spectrum disorder (ASD) and developmental language disorder (DLD). Despite the positive effects of the Pragmatic Intervention Programme (PICP) already known in both populations, the effects needed to be established with a larger sample and analysed separately for each condition. This study aims to analyse the effectiveness of PICP on preschool-age children with ASD or DLD with pragmatic impairment. A non-randomised controlled trial was conducted. Thirty-six children were assigned to experimental ( n = 22) or control group (waiting list) ( n = 14). Each child attended 24 PICP-based intervention sessions provided by a speech and language therapist. The primary outcome measure was a Goal Attainment Scale (GAS). The secondary outcomes were Escala de Avaliação de Competências Comunicativas (EAC) and Teste de Linguagem – Avaliação da Linguagem Pré-Escolar (TL-ALPE). The results indicated that all children achieved clinically significant progress in GAS after intervention. Statistically significant differences were observed between the experimental and control groups in the EAC and TL-ALPE after post-intervention assessment (T2). These results reinforce that PICP improves language in preschool-age children with ASD and DLD with pragmatic impairment. Differences between conditions and implications for future studies are discussed. Lay abstract Children diagnosed with autism spectrum disorder (ASD) and developmental language disorder (DLD) often have difficulties using language in social contexts. An intervention programme for preschool-age children with pragmatic difficulties, called Pragmatic Intervention Programme (PICP), showed positive effects for these children. However, it was important to confirm these effects with a larger group and analyse them separately for each condition. In this study, the effectiveness of the PICP was analysed in preschool-age children with ASD or DLD with difficulties in using language in social contexts. The study was carried out with 36 children. Twenty-two were allocated to an experimental group to receive the PICP-based intervention first, and 14 children were assigned to a control group (waiting list). Each child attended 24 PICP-based intervention sessions provided by a speech and language therapist. Progress was measured using a Goal Attainment Scale (GAS) and other language assessment instruments. The results showed that all children in the experimental group made significant progress in their language competencies, compared to the control group after the intervention. This study confirms that the PICP is effective in improving language competencies in preschool-age children with ASD and DLD with difficulties in using language for social purposes, regardless of their condition. These results emphasise the importance of tailored interventions for these children and point to areas for further research.