To explore the relationship between autistic clinical profiles and age at first concern and diagnosis among children with autism spectrum disorder. The clinical profiles included the severity of autism, cognition, adaptability, language development, and regression.
The multivariate linear regression model was used to examine the association of diagnostic age and first-concern age with autistic clinical profiles and with further stratification analysis.
A total of 801 autistic children were included. Language delay and regression were associated with earlier diagnostic age (language delay: crudeβ: −0.80, 95%CI%: −0.92–−0.68; regression: crudeβ: −0.21, 95%CI%: −0.43–−0.00) and the age of first concern of autistic children (language delay: crudeβ: −0.55, 95%CI%: −0.65–−0.45; regression: crudeβ: −0.17, 95%CI%: −0.34–−0.00). After stratification by sex, language delay tended to be more associated with the earlier diagnostic age among boys (crudeβ: −0.85, 95%CI%: −0.98–−0.72) than among girls (crudeβ: −0.46, 95%CI%: −0.77–−0.16). After stratification by maternal education level or family income level, language delay was most associated with the earlier diagnostic age in autistic children from families with higher socioeconomic levels.
Language delay, rather than other symptoms, promoted an earlier diagnostic age. Among male autistic children or children from families with higher socioeconomic levels, language delay was most significantly associated with an earlier age of diagnosis. Cognitive delay, or adaptive delay, was associated with a later age at diagnosis and presented only in autistic children from families with lower socioeconomic levels. There may be sex or socioeconomic inequality in the diagnostic age for autistic children. More publicity and public education about the diversity of autistic symptoms are urgently needed in the future, especially for low-socioeconomic families.