Factors Associated with a Delayed Autism Spectrum Disorder Diagnosis in Children Previously Assessed on Suspicion of Autism.

Doctors tracked 893 Danish kids who first tested negative for autism before age eight. They looked back at records to see who later got an ASD diagnosis and why it took longer. The team counted early signs, IQ scores, other delays, and parents’ schooling.

One in five kids who first screened negative were later diagnosed with ASD. Kids with subtle autism signs, low IQ, other developmental disorders, or parents who left school early had the longest wait. These red flags slipped through the first check-up.

Stephens et al. (2018) piles on more risk: children who face family adversity wait even longer—up to 23 percent—than the low-education group alone. Pettygrove et al. (2013) saw the same pattern years earlier across nine U.S. towns.

Fombonne et al. (2022) seems to disagree: Black and White preschoolers showed the same autism symptoms at referral, yet Black kids still got diagnosed later. The new study points to low parent education, but the 2022 paper says race matters beyond those numbers. Both can be true—system hurdles stack on top of family factors.

Meads et al. (2024) adds a new cost: the longer the delay, the higher the parent’s depression. Catching the missed 21 percent early could lift child and caregiver together.

If a child screens negative but has subtle signs, low IQ, or parents with little schooling, mark the chart for a re-screen in 12 months. Add travel help and clear next-step plans so the family does not drift. One extra visit can turn a three-year wait into early therapy and less stress for everyone.