Evaluating the Diagnostic and Concurrent Validity of the DREAM‐IT in Mandarin‐Speaking Toddlers With Autism Spectrum Disorder and Developmental Language Disorder

BACKGROUND: Early language delay is a common presenting concern among toddlers with autism spectrum disorder (ASD) and developmental language disorder (DLD), creating challenges for clinical assessment and referral decisions. Although ASD and DLD differ in core social-communicative features, restricted/repetitive behaviours, and developmental mechanisms, language-focused assessment may provide complementary information about early communicative profiles. However, culturally adapted tools for assessing early language and communication in Mandarin-speaking toddlers remain limited. METHODS: A total of 213 children aged 24-36 months (ASD = 89, DLD = 60, TD = 64) were recruited from the Child Healthcare Department of a tertiary hospital between 2020 and 2022. Clinical diagnoses were established by multidisciplinary teams based on DSM-5 and CATALISE criteria. Caregivers completed the Diagnostic Receptive and Expressive Assessment of Mandarin-Infant & Toddler (DREAM-IT), which evaluates receptive and expressive language, cognitive play, and social communication. Receiver operating characteristic (ROC) curve analyses assessed discriminative validity across diagnostic groups, logistic regression examined the contribution of DREAM-IT domains to ASD-versus-DLD classification, and concurrent validity was evaluated against GDS, ABC, CARS, and ADOS-2. RESULTS: DREAM-IT showed strong diagnostic accuracy in distinguishing children with ASD or DLD from TD children (AUC = 0.84-0.998), but its ASD-versus-DLD discrimination was domain-specific and more limited. Receptive language provided the strongest ASD-versus-DLD discrimination (AUC = 0.81; sensitivity = 69.1%; specificity = 84.3%; optimal cutoff = 86.5), whereas expressive language, cognitive play, and social communication showed poor-to-limited standalone performance (AUC = 0.51-0.57). Logistic regression indicated that receptive language (OR = 1.10, p < 0.05) and expressive language (OR = 0.77, p = 0.015) independent contributed to ASD-versus-DLD discrimination, with an overall classification accuracy of 79.2%. DREAM-IT classifications demonstrated moderate-to-substantial agreement with established developmental and autism-related instruments, including GDS, ABC, CARS, and ADOS-2 (Cohen's κ = 0.62-0.82). Developmental age comparisons revealed domain-specific lags, with ASD characterized by greater receptive and social delays and DLD showing the largest lag in expressive language. CONCLUSIONS: The Mandarin DREAM-IT provides clinically useful information about early language and communication development in Mandarin-speaking toddlers with ASD and DLD and shows moderate-to-strong concurrent alignment with established developmental and autism-related measures. Its primary value lies in characterizing domain-specific developmental patterns and offering useful complementary information within a broader, multi-method diagnostic framework for Mandarin-speaking populations. WHAT THIS PAPER ADDS: What is already known on this subject Differentiating autism spectrum disorder (ASD) from developmental language disorder (DLD) in toddlers is clinically important but challenging. Both conditions may present with early language delay, while ASD is characterised by core social-communication difficulties and restricted or repetitive behaviours. Accurate interpretation therefore requires a multi-method assessment integrating language evaluation, developmental history, direct observation, and autism-specific measures. However, culturally and linguistically appropriate tools for characterising early language and communication in Mandarin-speaking toddlers remain limited. What this study adds to the existing knowledge This study evaluated the diagnostic accuracy and concurrent validity of the Mandarin DREAM-IT in 213 toddlers with ASD, DLD, or typical development. DREAMIT showed good-to-excellent accuracy in distinguishing children with ASD or DLD from typically developing children, but ASD-versus-DLD discrimination was more limited and domain-specific. Receptive language provided the clearest discriminatory signal, whereas expressive language, cognitive play, and social communication showed substantial overlap. DREAM-IT developmental age scores showed moderate correlations with corresponding GDS measures, and its descriptive rule-based patterns showed substantial agreement with autism-specific instruments. What are the potential or actual clinical implications of this study? DREAM-IT may provide useful caregiver-reported information about receptive language, expressive language, cognitive play, and social communication in Mandarin-speaking toddlers. Its main clinical value lies in characterising domain-specific developmental patterns and providing complementary information within a broader, multi-method assessment framework. It should not be used as a standalone instrument to diagnose ASD or DLD or to differentiate between them. Results should be interpreted alongside developmental history, direct clinical observation, developmental testing, and autism-specific measures.