Persistence of Autism Spectrum Disorder From Early Childhood Through School Age.

This study followed 213 children diagnosed with autism between 12-36 months to see if they still met autism criteria at ages 5-7. About 37% no longer qualified for an autism diagnosis at follow-up. Children who no longer met criteria all had average or above-average intelligence, while those who still met criteria had varied intellectual abilities. Girls and children with better daily living skills at initial diagnosis were more likely to no longer meet autism criteria later.

This natural history cohort study followed 213 children diagnosed with autism spectrum disorder (ASD) at 12-36 months to determine diagnostic persistence at 5-7 years. Results showed 37.1% no longer met ASD criteria at follow-up (nonpersistent ASD). All children with nonpersistent ASD had IQ ≥70, while those with persistent ASD showed bimodal IQ distribution. Nearly all children (94.4%) received ASD-specific interventions, primarily applied behavioral analysis.

Multilevel logistic regression identified higher baseline adaptive skills and female sex as factors associated with nonpersistent ASD. The study provides important insights into early ASD diagnosis stability and factors influencing diagnostic outcomes over time.

Results suggest early ASD diagnoses should be monitored over time, particularly for girls and children with higher adaptive functioning. Clinicians should discuss diagnostic uncertainty with families. The high rate of nonpersistent diagnoses highlights the importance of ongoing assessment and may inform intervention planning and resource allocation decisions.

Single cohort study design limits generalizability. The study doesn't specify randomization or control groups. Potential selection bias in community-based intervention receipt. Limited details on intervention intensity, duration, or fidelity measures that could influence outcomes.

While the prevalence of autism spectrum disorder (ASD) continues to increase and early diagnosis is emphasized, there is limited information on outcomes for children diagnosed with ASD in early childhood using contemporary diagnostic criteria. To determine the frequency with which children who are clinically diagnosed with ASD at 12 to 36 months of age continue to meet diagnostic criteria for ASD at 5 to 7 years of age and to evaluate whether baseline child-specific and demographic characteristics and receipt of interventions are associated with ASD persistence. In this natural history cohort study, children who received a clinical ASD diagnosis at 12 to 36 months of age underwent a research diagnostic assessment at 5 to 7 years of age. Research assessments occurred from August 14, 2018, to January 8, 2022.

Children received community-based interventions, and parents provided details about interventions received. The main outcome was persistence of ASD diagnosis based on current functioning. An experienced research psychologist assigned an ASD diagnosis (present or absent) according to criteria from the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) after the research assessment. The research assessment included administration of the Autism Diagnostic Observation Schedule-2, Autism Diagnostic Interview-Research, and a cognitive measure.

Of the 213 participants diagnosed with ASD at initial clinical assessment (mean [SD] age, 24.6 [3.9] months; 177 boys [83.1%]), 79 (37.1%) did not continue to meet diagnostic criteria for ASD (nonpersistent ASD) at research assessment (mean [SD] age, 74.3 [7.1] months). All children with nonpersistent ASD had IQ of at least 70, while there was a bimodal distribution of IQ for those with persistent ASD (46 with IQ <70 and 88 with IQ ≥70). All children received some interventions, and 201 (94.4%) received ASD-specific intervention, mostly applied behavioral analysis. In a multilevel logistic regression model, the only variables associated with increased odds of being in the nonpersistent ASD group at 6 years of age were higher baseline adaptive skills (b coefficient = -0.287 [SE, 0.108]) and female sex (b = 0.239 [SE, 0.064]).

The findings of this cohort study suggest that among toddlers diagnosed with ASD, baseline adaptive function and sex may be associated with persistence of ASD.