Utility of Early Communication Assessment within ASD Diagnostic Evaluations in the Second Year of Life

Background:

The AAP continues to support screening, early diagnosis, and timely referral for intervention, yet there is a lack of readily used standardized assessment instruments specific and sensitive enough to detect ASD red flags and inform intervention prior to comprehensive ASD evaluation. Parents often cite speech concerns early on, leading many families to seek a speech-language evaluation prior to comprehensive ASD evaluation (Chawarska, Paul, Klin et al., 2007), positioning speech-language pathologists (SLPs) at the front lines for detecting and quantifying ASD red flags in toddlers. Paul (2014) emphasizes that measuring frequency, range, and means of communication is necessary to capture a child’s current communication abilities at the prelinguistic phase, while simultaneously measuring unusual communicative patterns (echolalia, significant deficits in pragmatics and receptive language). Further, the ASHA Ad hoc Committee on ASD (2006) states that SLPs play a critical role in screening, early detection of children at-risk for ASD, and referrals for further evaluation, while also formulating intervention specific to social communication delays. Additionally, given the complexity of ASD, varied levels of functioning, and need to distinguish ASD from other disorders, interdisciplinary collaboration within the diagnostic process is considered best practice.

Objectives:

To examine how early communication assessment, using the CSBS-DP, correlates to the ADOS-2 Toddler Comparison Score within an ASD diagnostic evaluation, among 2 diagnostic groups: ASD and language delay (LD).

Methods:

54 toddlers, ages 14-24 months, participated in a study evaluating toddlers suspected of ASD. Clinicians assessed participants at a single visit (Mean Age=21.44 months, SD=2.33), 40 received an ASD diagnosis [77.5% male (n=31), 22.5% female (n=9)] and 14 received a language delay (LD) diagnosis [64.3% male (n=9) and 35.7% female (n=5)]. Assessment battery included Communication Symbolic Behavior Scales-Developmental Profile (CSBS-DP; social, speech, symbolic composites), Mullen Scales of Early Learning, and ADOS-2. The standardized calibrated severity score (CSS) was generated as a metric of relative severity of ASD symptoms for each ADOS-2. Differences in CSBS-DP composite scores and CSS among the two diagnostic outcome groups were assessed using two-sample t-tests. Age-adjusted tests and gender by diagnosis interactions for each measure were assessed using linear regression and two-way ANOVAs.

Results:

Results revealed significant differences on CSBS-DP composites between the two diagnoses, ASD and LD, with LD toddlers receiving higher scores across all three composites (Speech: p<.001, Social: p<.001, Symbolic: p<.001). ASD toddlers received significantly higher CSS scores than LD toddlers (p<.001). Analyses revealed age-adjusted results as complimentary to the t-tests for all measure outcomes. However, a significant interaction between gender and diagnosis for Symbolic composite was observed (p=0.016), with ASD males receiving higher scores than ASD females and LD females receiving higher scores than LD males. All other interactions between gender and diagnosis were not significant.

 Conclusions: The results contrast and differentiate communication skills of ASD and LD toddlers as measured by the CSBS-DP. These findings support the use of the CSBS-DP within a comprehensive ASD evaluation, by capturing verbal and nonverbal communication, highlighting social communication vulnerabilities, and leading SLPs to make informed decisions regarding further evaluation and treatment planning.