Clinical practice guideline: Interventions for Developmental Language Delay and Disorders.

Background: Approximately 9.9 % of children present with difficulties in language development (DLD), 7.6 % without serious additional impairments and 2.3 % associated with languagerelevant comorbidities, e.g., hearing loss. Notably, in a consensus statement by experts in German-speaking countries, in the guideline presented here, and further in this article, all of these disorders are referred to as "developmental language disorders" (DLD), whereas the international consortium CATALISE only refers to those without comorbidities as DLD. DLDs are among the most commonly treated childhood disorders and, if persistent, often reduce educational and socio-economic outcome. Children in their third year of life with developmental language delay (late talkers, LT) are at risk of a later DLD.

Methods: This German interdisciplinary clinical practice guideline reflects current knowledge regarding evidence-based interventions for developmental language delay and disorders. A systematic literature review was conducted on the effectiveness of interventions for DLD.

Results: The guideline recommends parent training (Hedges g = 0.38 to 0.82) for LTs with expressive language delay, language therapy (Cohen's d = -0.20 to 0.90) for LTs with additional receptive language delay or further DLD risk factors, phonological or integrated phonological treatment methods (Cohen's d = 0.89 to 1.04) for phonological speech sound disorders (SSDs), a motor approach for isolated phonetic SSDs (non-DLD), and for lexical-semantic and morpho-syntactic impairments combinations of implicit and explicit intervention approaches (including input enrichment, modeling techniques, elicitation methods, creation of production opportunities, metalinguistic- approaches, visualizations; Cohen's d = 0.89-1.04). Recom mendations were also made for DLD associated with pragmatic-communicative impairment, bi-/ multilingualism, hearing loss, intellectual disability, autism-spectrum disorders, selective mutism, language- relevant syndromes or multiple disabilities, and for intensive inpatient language rehabilitation.

Conclusion: Early parent- and child-centered speech and language intervention implementing evidence-based intervention approaches, frequency, and settings, combined with educational language support, can improve the effectiveness of management of developmental language delay and disorders.