Intervention studies with group design targeting expressive phonology for children with developmental speech and language disorder: A systematic review and meta-analysis.

What is already known on the subject An increasing number of interventions is available for children and adolescents with developmental speech and/or language disorders. Previous reviews suggest relatively low levels of evidence of interventions having phonology as an outcome measure. What this paper adds to the existing knowledge This review and meta-analysis summarise the intervention evidence from a substantial body of group design studies, indicating positive results from a range of interventions with phonological outcomes. It highlights the need to systematically implement and replicate different intervention procedures to understand factors that will maximise positive outcomes and to grow the evidence base for best practice. What are the potential or actual clinical implications of this study? Tentative evidence is emerging for the effectiveness of various approaches in enhancing speech production accuracy skills of children and adolescents with developmental speech and/or language disorder.