Delay of diagnosis in autism spectrum disorder and its influencing factors

Abstract

Background Although experienced clinicians are capable of diagnosing autism spectrum disorders (ASD) in children before they reach the age of 2, the average age of diagnosis reported internationally is between 4 and 5 years, indicating a significant delay in diagnosis. The objective of this study was to determine the factors influencing the diagnosis delay time (DDT) in children with ASD and to shorten the diagnosis period. Methods We employed the Cox proportional hazard model to examine the effects of individual, family, sociodemographic, and healthcare system indicators on DDT in a retrospective survey involving ASD children and their families. Results This study included a total of 560 subjects. The findings revealed that the median DDT in children with ASD was 8.16 (15.99) months, and the mean DDT was 13.68 (17.11) months. Language development level of children (RR = 0.521, 95%CI 0.400 ~ 0.680, P < 0.001), enrollment in school (RR = 1.950, 95%CI 1.552 ~ 2.450, P = < 0.001), experience of previous misdiagnosis (RR = 1.637, 95%CI 1.249 ~ 2.146, P < 0.001), degree of caregiver's concern about initial symptoms (RR = 0.781, 95%CI 0.635 ~ 0.960, P = 0.019), and whether the initial symptom is a core defect of ASD (RR = 1.758, 95%CI 1.210 ~ 2.553, P = 0.003) were identified as independent risk factors for delayed diagnosis of ASD in children under the age of six. Conclusions In China, there is a significant delay in the diagnosis of ASD among children. Children at risk of delayed ASD diagnosis include those with normal language abilities and early-onset non-autistic core difficulties, whose parents neglect their children’s atypical symptoms, those who have already started school, and those with a history of misdiagnosis. We urge parents, educators, and healthcare providers to closely monitor atypical child development during early childhood, enhance growth monitoring for preschool and school-aged children, and be attentive to children with normal language skills.