Modification and Validation of an Autism Observational Assessment Including ADOS-2 for Use with Children with Visual Impairment.

Children with visual impairment (VI) are at risk of autism spectrum disorder (ASD); however standard observational diagnostic assessments are not validated for this population. The primary objective of the study is to validate a modified version of the Autism Diagnostic Observation Schedule (ADOS-2, Module 3), for children with VI. A cross-sectional observational study was undertaken with 100 (mean 5½ years, SD 10.44 months, range 4-7 years; 59 (59%) males) children with congenital disorders of the peripheral visual system with moderate/severe-profound VI. As the primary objective, 83 (83%) who were 'verbally fluent' were assessed with the modified ADOS-2 (Module 3). Their scores were investigated for reliability, construct and criterion validity against expert clinician formulation and parent-rated social and communication questionnaires (Social Responsiveness Scale-2, SRS-2; Children's Communication Checklist-2). The secondary objective with the total sample was to report on frequency and distribution of ASD ratings in this VI population. The modified ADOS-2 (Module 3) was found to have strong internal coherence and construct validity (two factor model) and inter-rater reliability. A new VI diagnostic algorithm was established which showed high sensitivity and specificity against clinician formulation. Using the best cut-off threshold for 'High Risk for ASD', strong concurrent criterion validity was found according to parent-rated scores on the SRS-2. The modified ADOS-2 (Module 3) was shown to have promising reliability and validity in establishing children at 'High Risk of ASD' in this vulnerable population. Elevated rates of ASD were found across the sample, in line with previous estimates.