The impact of diagnostic timing on healthcare use: statistical trends among early- and later-diagnosed autistic youth

Autism is a neurodevelopmental condition affecting approximately 1 in 50 Canadian children, with increasing prevalence over the past two decades, males being diagnosed at a four to one ratio to females, and a growing trend of later diagnoses in childhood/adolescence. While receiving a diagnosis after age six years is associated with co-occurring mental health conditions, little is known about how diagnostic timing influences healthcare service use patterns. Objectives This study examined whether later-diagnosed Autistic youth access more psychiatric healthcare services than those diagnosed earlier. Methods Participants included 147 Autistic youth from a public pediatric diagnostic clinic affiliated with a major children's hospital (median age at assessment = 5.00 years; 24.49% female). Healthcare utilization data were obtained from the National Ambulatory Care Reporting System (NACRS), including various healthcare visits. Negative binomial regression analyses determined whether diagnostic timing predicted number of healthcare encounters with sex as a moderator. Results Groups were comparable in size (54% early diagnosed) and sex distribution. Controlling for age, being diagnosed later in adolescence predicted 59% more psychiatric visits ( β = 0.47, p = .024). This effect was reduced and no longer statistically significant when sex was included as a moderator ( β = 0.42, p = .066). Conclusions Later-diagnosed Autistic youth used more psychiatric services; however, with an underpowered sample, we were not able to detect sex-related differences. These findings highlight how diagnostic timing is potentially associated with the mental well-being and healthcare usage of Autistic youth, underscoring the need for targeted supports following a later autism diagnosis.