Restrictions on in-person assessments during the COVID-19 pandemic were a challenge for an adult autism diagnostic service receiving over 600 referrals annually. The service sought to adapt the Autism Diagnostic Observation Schedule (ADOS-2) for online administration.

To investigate whether an online adaptation of the ADOS-2 performed comparably to the in-person ADOS-2. To obtain qualitative feedback from patients and clinicians regarding experiences of the online alternative.

Online ADOS-2 assessments were completed for 163 referred individuals. A matched-comparison group comprised 198 individuals seen for an in-person ADOS-2 assessment prior to COVID-19 restrictions. A two-way analysis of variance (ANOVA) was run to explore any effect of assessment type (online or in-person ADOS-2) and gender on total ADOS score. Qualitative feedback was collected from 46 patients and 8 clinicians involved in diagnostic decision-making after the online ADOS-2 assessment.

A two-way ANOVA found no significant effect of assessment type or gender and no assessment type × gender interaction effect on total ADOS score. Qualitative feedback suggested that only 27% of patients would have preferred an in-person assessment. Nearly all clinicians reported gains from offering an online alternative.

This is the first study to examine an online adaptation of ADOS-2 within an adult autism diagnostic service. It performed comparably to the in-person ADOS-2, making it a viable alternative when in-person assessments are not possible. As this clinic group has high rates of comorbid mental health difficulties, we encourage further work to determine whether online assessment approaches generalise to other services to increase options for patients and efficiencies for service delivery.