The Influence of Quantitative Intervention Dosage on Oral Language Outcomes for Children With Developmental Language Disorder: A Systematic Review and Narrative Synthesis

= 3-18 years); oral language interventions with phonology, vocabulary, or morphosyntax outcomes; and experimental manipulation or statistical analysis of any quantitative aspect of dosage. Studies were appraised using the Cochrane risk-of-bias tool. Results Two hundred forty-four articles reported on oral language interventions with children with DLD in the domains of interest; 13 focused on experimentally/statistically manipulating quantitative aspects of dosage. No article reported phonological outcomes, three reported vocabulary, and eight reported morphosyntax. Dose frequency was the most common characteristic manipulated. Conclusions Research is in its infancy, and significant further research is required to inform speech-language pathologists in practice. Dosage characteristics are rarely adequately controlled for their individual effects to be identified. Findings to date suggest that there is a point in vocabulary and morphosyntax interventions after which there are diminishing returns from additional dosage. If dose is high (number of learning opportunities within a session), then the literature suggests that session frequency can be reduced. Frequent, short sessions (2/3 × per week, approximately 2 min) and less frequent, long sessions (1 × per week, approximately 20 min) have yielded the best outcomes when composite language measures have been used; however, replication and further research are required before clinicians can confidently integrate these findings into clinical practice. Supplemental Material https://doi.org/10.23641/asha.13570934.