Early Identification of ASD in Males and Females: Sex-Specific Behavioral Phenotypes in Toddlers Assessed with the STAT and STAT-Q Parent Questionnaire
Recent research suggests that a two-tiered screening method utilizing the STAT shows strong positive predictive value and sensitivity as well as a reduction in the false positive rate of diagnosis. Previous research at our clinic examining the STAT and STAT-Q identified a possible specific behavioral phenotype in boys and girls. Literature comparing the male to female ratio of diagnoses of ASD suggests that girls who meet the diagnostic criteria of ASD are at a disproportionate risk of not receiving the diagnosis. The majority of literature on sex differences among children diagnosed with ASD examines differences after the age of 6 years. These differences include less restrictive, repetitive, and stereotyped behaviors, namely less meltdowns, decreased frequency in occurrence, symptom masking, and more age and gender-appropriate interests and play. Given the importance of early identification and intervention, an improved understanding of sex differences in young toddlers is needed to ensure children are being more accurately diagnosed and receive early intervention.
This study aims to examine sex differences in toddlers assessed by clinicians using the STAT and the STAT-Q parent questionnaire to further refine potential diagnostic markers for the early identification of ASD in males and females.
This retrospective record review examines 139 children aged 18 to 36 months who were assessed through a multidisciplinary medical diagnostic evaluation utilizing the STAT and STAT-Q. Multivariate regression was used to examine the relationships between the STAT and biological sex adjusted for developmental age, mother’s language and STAT-Q.
Among a sample of 139 children (median age 33 months, range 19 – 36 months), boys (N=109, 78%) displayed a higher median score (2.75 vs 2.25 in girls, p=0.047) on the STAT, indicating greater severity of symptomatology associated with ASD. Adjusted for other factors, boys on average scored 0.4 higher on the STAT than girls (p=0.009). Furthermore, an average female score of 2.4 among 34 girls assessed suggests a greater likelihood that females may be missed. While a preliminary item analysis is inconclusive with the current sample size, an item analysis will be repeated upon obtaining additional participants to further examine if specific items on the STAT and STAT-Q strongly correlate with a diagnosis of ASD for males and females.
Improved understanding of sex differences among male and female toddlers on the STAT and STAT-Q may improve clinical judgment combined with these assessment tools to assist in appropriately diagnosing both males and females with ASD. An understanding of the sex-specific behavioral phenotypes in the presentation of ASD in young children will help improve early identification and early implementation of the necessary interventions needed to enhance outcomes throughout the lifespan.