Identifying Developmental Language Disorder in Vietnamese Children

Abstract

Purpose Developmental language disorder (DLD), defined by low language performance despite otherwise normal development, can negatively impact children's social and academic outcomes. This study is the 1st to examine DLD in Vietnamese. To lay the foundation, we identified cases of DLD in Vietnam and explored language-specific characteristics of the disorder. Method Teacher ratings of 1,250 kindergarteners living in Hanoi, Vietnam, were used to recruit children with and without risk for DLD. One hundred four children completed direct measures of vocabulary and language sampling, and their parents completed in-depth surveys. We examined convergence and divergence across tasks to identify measures that could serve as reliable indicators of risk. Then, we compared performance on direct language measures across ability levels. Results There were positive associations between teacher and parent report and between report and direct language measures. Three groups were identified based on convergence across measures: DLD, some risk for DLD, and no risk. The DLD group performed lowest on measures of receptive and expressive vocabulary, mean length of utterance, and grammaticality. Although children with DLD exhibited a greater number of errors, the types of errors found were similar across DLD and No Risk groups. Conclusions Similar to rates found globally, 7% of the kindergarten population in Vietnam exhibited risk for DLD. Results highlight the importance of parent and teacher report and the value of multiple measures to identify DLD. We discuss potential clinical markers for DLD in the Vietnamese language and outline future directions.

Figure 1.

Flow chart representing the steps of the study including recruitment, exclusionary criteria, assessment types, and classification into three groups: children with developmental language disorder (DLD), children with some level of risk for developmental language disorder (Some Risk), and children with no risk (No Risk; i.e., typically developing).

Figure 2.

Individual child profiles are displayed from the three groups of DLD (top), Some Risk (middle), and No Risk (bottom). Profiles consist of z scores from the three report measures (ITALK, FOCUS, and Milestones) and six direct measures (ExpVoc, RecVoc, MLU, Gram, SI, and Story). Profiles are displayed from youngest to oldest and are labeled by age (in months) and gender (M = male; F = female). Individual children from the Some Risk and No Risk groups were selected to match the individual DLD profiles by age (±1 month) and gender. DLD = developmental language disorder; ITALK = Instrument to Assess Language Knowledge; FOCUS = Focus on the Outcomes of Communication Under Six; ExpVoc = expressive vocabulary; RecVoc = receptive vocabulary; MLU = mean length of utterance; Gram = grammaticality; SI = subordination index; Story = story structure.