A global perspective of the prevalence of low language in children: a scoping review and evidence and gap map protocol

ObjectiveThe objective of this scoping review is to identify, categorize, and map the existing evidence of low language prevalence in children aged 4 to 18 years globally. Additionally, it seeks to explore associated factors, and map evidence gaps to improve future reporting practices. IntroductionThe study of language difficulties in children has evolved over the years, marked by changing terminologies and criteria. Understanding why prevalence varies is critical to address the need for accurate prevalence estimates, highlight factors influencing reported frequency, and inform policy, resource allocation, and research priorities. Inclusion criteriaThis review will consider studies that report low language prevalence for children aged 4 to 18 years from any country that are derived from studies or epidemiological samples in community/population settings, including households, birth registers/cohorts, and schools. To encompass the changing use of terminologies and criteria, the term low language is used as an umbrella term to describe children whose language development is behind their peers. MethodsThis review protocol is guided by the Joanna Briggs Institute methodology for scoping reviews. Key databases will be systematically searched for English-language studies, published between 01 January 1970 to 30 June 2023. Two independent reviewers will screen titles and abstracts, while three reviewers will assess full texts. The final selection of studies will undergo review by a broader expert group and data extraction will be conducted by one reviewer and verified for accuracy. The findings will be presented in narrative format, including tables and figures to aid in data presentation.