Parent‐reported Autism Diagnostic Stability and Trajectories in the Longitudinal Study of Australian Children

Abstract

This study aimed to explore the stability of parent‐reported diagnosis of Autism Spectrum Disorder (ASD) and factors influencing the trajectories in two cohorts from the prospective Longitudinal Study of Australian Children (LSAC). Parent‐reported ASD diagnosis was collected for children from 6 years of age in a Birth cohort and 10 years of age in a Kinder cohort; allowing for exploration of diagnostic stability at age 6, 8, 10, and 12 years (Birth cohort) and 10, 12, 14, 16 years (Kinder cohort). Children were grouped based on persisting, desisting, inconsistent and late (diagnosis after 6 years—Birth cohort; after 10 years—Kinder) subgroups over four timepoints. Multinomial logistic regression explored predictors of diagnostic trajectories; generalized estimating equations examined trajectories of emotional and behavioral problems. Of 66 Birth cohort children parent‐reported to have ASD at age 6, with data at all four time points, 14% did not at 12 years; of 73 Kinder cohort children at age 10 years, 26% no longer had parent‐reported ASD at 16 years. Children with late diagnoses showed increasing trajectories of emotional and behavioral problems, while children with persisting or desisting diagnoses showed decreasing trajectories. Between 86% and 74% had a reported ASD diagnosis after 6 years. Findings indicate that children with ASD need services and supports that can adapt to their changing needs, which may be increasing, decreasing or different. This has implications for the provision of services and funding. Lay Summary This study explored how consistent parent‐reported ASD diagnosis is over time in two groups of children from the Longitudinal Study of Australian Children (LSAC). Although up to 26% of children no longer had parent‐reported ASD after 6‐years follow up, persisting or late trajectories were more common. The outcome of late onset trajectories requires ongoing review. Autism Res 2021, 14: 773–786. © 2021 International Society for Autism Research and Wiley Periodicals LLC

Mental health and social difficulties of late‐diagnosed autistic children, across childhood and adolescence

“…Our finding that earlier‐diagnosed children tended to show a decreasing trajectory of EBSDs, whereas later‐diagnosed children show an increasing trajectory replicates recent findings from an Australian population‐representative cohort study (May et al., 2021 ). Based on both sets of findings, we hypothesise that the relationship between early EBSDs and earlier autism diagnosis involves a child experiencing overt functional difficulties and reduced quality of life, and therefore being more likely to be identified as needing assessment.…”

“…The current study extends the small extant literature using prospective data to chart trajectories of emotional and behavioural problems of autistic people (e.g., Anderson, Maye, & Lord, 2011;Colvert et al, 2021;Gotham, Brunwasser, & Lord, 2015;May et al, 2021;Shattuck et al, 2007;Stringer et al, 2020). Also, our work can help elucidate contradictory findings in previous studies of EBSDs.…”

“…In the current study, we use longitudinal data from the UK's Millennium Cohort Study to chart trajectories of EBSDs of autistic children from early childhood to middle adolescence (ages 3-14 years). We seek to replicate and extend the findings of May et al (2021) in a UK sample, leveraging our access to a larger sample size by: (i) investigating subtypes of EBSD, rather than treating this as a unitary construct, to accommodate the potential for distinct trajectories for different types of EBSD; (ii) extending the age range studied to include EBSDs reported at aged 3 and 5 years and (iii) using statistical methods that can account for both between-and within-child variation in ESBDs. We will investigate whether there are patterns of within-person change characteristic of late-diagnosed autistic children, who we define as those receiving their diagnosis after the early stages of their primary education (i.e., after age 7 years).…”

“…Such approaches overlook co‐occurring difficulties that, for one reason or another, have not attracted a formal diagnosis. One recent Australian study addressed this limitation by investigating timing and stability of ASD diagnosis in relation to the trajectory of prospectively measured EBSDs in two cohorts of children (Birth Cohort, aged 6–12 years, N = 66; Kinder Cohort, aged 10–16 years, N = 77) (May et al., 2021 ). Using a single measure of overall EBSDs, they found distinct trajectories for earlier‐diagnosed and later‐diagnosed groups.…”

Mother and child mental health over time in children with Autism and/or ADHD in the Longitudinal Study of Australian Children

“…There was no measure of ASD symptoms and diagnoses of ASD and ADHD were not validated by researchers or clinicians, and are solely based on parent report. We have explored some of these issues in our prior work (May et al, 2021) but also note that parent report of a diagnosis is usually accurate (Daniels et al, 2012). Verifying diagnoses would be important future work, however, may not be feasible in these types of large longitudinal studies.…”