ADOS Autism Severity As a Predictor of Language Ability in Boys and Girls with Autism Spectrum Disorder

Background:

Autism is a neurodevelopmental disorder that affects 1 in 42 boys and 1 in 189 girls (Christensen et al. 2016). Due to this large discrepancy, there has been relatively little research that explores how autism presents in girls. Of the research that has been done, recent findings suggest that girls with autism have worse communication skills than boys of similar autism severity as measured by the autism diagnostic observation schedule (ADOS) (Hartley and Sikora 2009).

Objectives:

In the current study, we aim to examine how receptive and expressive language performance relates to ADOS autism severity scores differently in girls and boys with autism. Given the subject sample spans puberty, we assess whether these associations are different based on pubertal status in both sexes.

Methods:

Data were collected from 29 prepubescent boys, 20 post pubescent boys, 16 prepubescent girls, and 35 post pubescent girls with autism or autism spectrum diagnoses. Pubertal cutoffs were determined using the Pubertal Development Scale, autism severity was determined using the autism diagnostic observation schedule, second edition (ADOS-2), IQ was determined using the differential abilities scale (DAS), and receptive and expressive language ability were determined using the clinical evaluation of language fundamentals, fourth edition (CELF-4). IQ, age, and receptive and expressive language scores were not significantly different between boys and girls in prepubescent and post pubescent groups respectively. Eight linear regressions were run (separate tests for each sex and pubertal group for two outcome variables) with ADOS score sum predicting either expressive or receptive language scores to assess the associations between autism severity and language ability.

Results:

Preliminary analysis revealed that autism severity significantly predicted receptive language in post pubescent girls (p = .016, t = -2.526, Beta = -.403). There were marginal effects found in which autism severity predicted expressive language (p = .075, t = -1.926, Beta = -.458) and receptive language (p = .071, t = -1.952, Beta = -.462) in prepubescent girls as well as expressive language in post-pubescent girls (p = .077, t = -1.824, Beta = -.303). Autism severity did not significantly predict receptive or expressive language performance for any other group.

Conclusions:

Based on these findings, ADOS severity relates to the measure of receptive language in post pubescent girls more robustly than in boys at any pubertal stage. Additionally, the relationship suggests that receptive language ability decreases with increasing autism severity in post pubescent girls. Data collection is ongoing and more subjects will be added to increase statistical power and to see if any more significant effects are created.