Objective: Autism diagnosis is fraught with inequities, including misdiagnosis and delayed identification that disproportionately affect minoritized youth. Aspects of clinician decision-making, particularly diagnostic certainty, may contribute to these inequities. Little is known about how closely clinician certainty corresponds with autistic traits, nor whether certainty relates to socio-demographic factors.
Method: Autistic youth from the Simons Simplex Collection (N = 2,853) completed assessments after which clinicians rated how certain they were that the child met autism diagnostic criteria. Core clinical factors included clinician-observed (Autism Diagnostic Observation Schedule; ADOS) and parent-reported autistic traits (Social Communication Questionnaire), and an overall IQ score.
Results: Clinician certainty was moderately positively associated with parent-reported and observed autistic traits and was just as strongly negatively associated with IQ. Socio-demographic factors significantly associated with certainty, even accounting for clinical measures. Lower income and older child age related to less certainty. In contrast, clinicians rated higher certainty for youth identified as Hispanic, Black or African American, or Asian. Race and income also moderated the concordance between certainty with clinical factors. The agreement between higher ADOS scores and higher certainty was significantly weaker for lower-income families. The association between lower IQ and higher certainty was non-significant for Asian youth.
Conclusions: Diagnostic certainty ratings do not necessarily correspond closely with the level of autistic traits, and clinician perception of autism diagnosis may be related to demographic factors. Caution is needed when relying on clinician certainty to inform diagnosis. Future research on diagnostic practices is urgently needed among diverse and minoritized communities.