Sex Difference in Diagnosis Retention of an Autism Spectrum Disorder (ASD)

Background: Research findings suggest that although most children retain an ASD diagnosis after the initial diagnosis, some children may experience sufficient change in symptoms such that they no longer meet criteria for an ASD diagnosis at a later time. 

Objectives: To examine whether there is a sex difference in retention of ASD diagnosis and the factors that contribute to ruling out an earlier ASD diagnosis. 

Methods: This study utilized data from the Autism and Developmental Disabilities Monitoring Network, a population-based ASD surveillance system for 8-year-old children living in 14 US communities in 2008. 7,077 males and 1,487 females had an ASD diagnosis documented in their school or health records. ASD diagnosis retention status was determined by reviewing whether an ASD diagnosis was later ruled out by a community professional following a documented ASD diagnosis. Children were defined as either retaining an ASD diagnosis (ASD-R) or not retaining an ASD diagnosis (ASD-NR) if a community professional ruled-out an ASD after the date of first documented ASD diagnosis. Multivariable logistic regression was used to examine associations between the co-occurring conditions and diagnosis retention status in males and females.  

Results: Most children retained their ASD diagnosis (91% of both males and females). For those who did not, the diagnosis retention time was shorter for males than for females. Some factors, such as diagnosing professional and type of concurrent diagnoses, were differentially associated with diagnosis retention in boys and girls. Factors similarly associated with ASD diagnosis retention in males and females were meeting the ASD surveillance definition, having a higher degree of impairment associated with ASD, and having fewer co-occurring developmental and psychiatric diagnoses. After adjusting for child race, source of surveillance record, and surveillance year, both intellectual disability and sensory integration disorder were associated with ASD-NR in males, whereas developmental disability (DD)-personal/social was associated with ASD-NR in females. Furthermore, both males and females who had co-occurring developmental delays in motor areas or overall, language disorder, Attention-Deficit/Hyperactivity Disorder, learning disability, or any co-occurring developmental diagnosis were more likely to be ASD-NR.  Children with co-occurring Oppositional Defiant, anxiety, or mood disorder, or any psychiatric diagnosis were more likely to be classified as ASD-NR than their counterparts without these conditions - this was true in males and in females.  Diagnoses of Obsessive-Compulsive or bipolar disorder were associated with ASD-NR in males, but not in females. Hearing loss was associated with ASD-NR in males, whereas epilepsy or any co-occurring neurological diagnoses were associated with ASD-NR in females.  

Conclusions: While most children retained their ASD diagnosis through age 8, child sex plays a role in specific characteristics associated with the ASD diagnostic trajectory documented by community professionals. Milder ASD impairment and greater numbers of co-occurring conditions may complicate the diagnostic picture, leading to increased likelihood of an ASD diagnosis eventually being ruled out. Our findings highlight the need for clinicians to be aware of potential challenges with differential ASD diagnosis and co-occurring conditions that may challenge an appropriate diagnosis of ASD for boys and girls at young ages.