Gender Differences: Confirmatory Factor Analysis of the ADOS-II.

This study looked at how boys and girls with autism score differently on a common autism assessment tool (ADOS-II). Researchers found that certain test items work differently for boys versus girls - some autism signs are stronger indicators in girls while others are stronger in boys. This suggests the test might not measure autism the same way for both genders, which could affect how autism is diagnosed in girls.

This secondary data analysis examined gender differences in the ADOS-II Module 3 using confirmatory factor analysis with 4,100 youth diagnosed with autism (813 female, 3,287 male, average age 9.9 years). The study found that four ADOS-II items showed different factor loadings between genders: one social communication item and one restricted repetitive behavior (RRB) item were more strongly related to the underlying autism construct in females, while two RRB items had larger factor loadings in males. These findings suggest that the assumption of identical latent factor structure for ADOS-II Module 3 across genders may not be justified, potentially having diagnostic implications for how autism presents differently in girls versus boys.

These findings suggest current ADOS-II scoring may not equally capture autism presentations across genders, potentially contributing to diagnostic disparities. Clinicians should consider gender-specific item interpretation and the possibility that standard cutoffs may not be optimal for both males and females when using ADOS-II Module 3.

The abstract does not specify study methodology details, potential confounding variables, or sample characteristics beyond basic demographics. The clinical significance of the factor loading differences and their practical impact on diagnostic accuracy are not quantified.

Recent research has suggested that autism may present differently in girls compared to boys, encouraging the exploration of a sex-differential diagnostic criteria. Gender differences in diagnostic assessments have been shown on the ADOS-II, such that, on average, females score significantly lower than males on all scales and are less likely to show atypicality on most items related to social communicative difficulties. Yet, gender differences in the latent structure of instruments like the ADOS-II have not been examined systematically. As such, this secondary data analysis examined 4,100 youth diagnosed with autism (M= 9.9, 813 female & 3287 male) examined item response trends by gender on the ADOS-II Module 3.

Multi-Group Confirmatory Factor Analysis results show that the factor loadings of four ADOS-II items differ across the genders. One SCD item and one RRB item are strongly related to the latent factor in the female group, while two RRB items have larger factor loadings in the male group. The assumption of an identical latent factor structure for the ADOS-II Module 3 for males and females might not be justifiable. Possible diagnostic implications are discussed.