The prevalence of and potential risk factors for Developmental Language Disorder at 10 years in the Raine Study.

Aim: This study sought to determine the prevalence of Developmental Language Disorder (DLD) in Australian school-aged children and associated potential risk factors for DLD at 10 years.

Methods: This study used a cross-sectional design to estimate the prevalence of DLD in Generation 2 of the prospective Raine Study. Participants included 1626 children aged 10 years with available language data. Primary outcomes included variables matching diagnostic criteria for DLD. Associations of other potential prenatal and environmental variables were analysed as secondary outcomes.

Results: The prevalence of DLD in this sample was 6.4% (n = 104) at 10 years. This sub-cohort comprised 33.7% (n = 35) with expressive language deficits, 20.2% (n = 21) with receptive language deficits, and 46.2% (n = 48) with receptive-expressive deficits. No significant difference in sex distribution was observed (52.9% male, p = 0.799). Children who were exposed to smoke in utero at 18 weeks gestation were at increased risk of DLD at 10 years (OR = 2.56, CI = 1.23-5.35, p = 0.012).

Conclusions: DLD is a relatively prevalent condition in Australian children, even when assessed in middle childhood years. These findings can inform future research priorities, and public health and educational policy which account for the associations with potential risk factors.