Exclusion of females in autism research: Empirical evidence for a “leaky” recruitment‐to‐research pipeline

Abstract

Autism spectrum disorder (ASD) is characterized by challenges in social communication and the presence of repetitive behaviors or restricted interests. Notably, males are four times as likely as females to be diagnosed with autism. Despite efforts to increase representation and characterization of autistic females, research studies consistently enroll small samples of females, or exclude females altogether. Importantly, researchers often rely on standardized measures to confirm diagnosis prior to enrollment in research studies. We retrospectively analyzed the effects of one such measure (Autism Diagnostic Observation Schedule, ADOS) on research inclusion/exclusion rates by sex in autistic adults, all of whom had a preexisting community diagnosis of autism (n = 145, 95 male, 50 female). Using the ADOS as a confirmatory diagnostic measure resulted in the exclusion of autistic females at a rate over 2.5 times higher than that of autistic males. We compared sex ratios in our sample to those in other large, publically available datasets that rely either on community diagnosis (6 datasets, total n = 42,209) or standardized assessments (2 datasets, total n = 214) to determine eligibility of participants for research. Reliance on community diagnosis rather than confirmatory diagnostic assessments resulted in significantly more equal sex ratios. These results provide evidence for a “leaky” recruitment‐to‐research pipeline for females in autism research. Lay Summary Despite efforts to increase the representation of autistic females in research, studies consistently enroll small samples of females or exclude females altogether. We find that despite making up almost 50% of the initially recruited sample based upon self‐report of community diagnosis, autistic females are disproportonately excluded from research participation as a result of commonly used autism diagnostic measures. In our sample, and several other publically available datasets, reliance on community diagnosis resulted in significantly more equal sex ratios.

Roadblocks and detours on pathways to a clinical diagnosis of autism for girls and women: A qualitative secondary analysis

“… 28 Moreover, recent research suggests that girls and women diagnosed with autism using the Autism Diagnostic Observation Schedule (ADOS) may present with the characteristics that are closer to those of boys and men and may not be representative of autistic girls and women more broadly. 29 Thus, inclusion of lived experiences of autistic girls and women across the lifespan in this study enriches our understandings of what contributes to a later diagnosis of autism.…”

Sex differences in early autism screening using the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT-R/F)

“…Furthermore, it is crucial to keep in mind that the M-CHAT-R/F as well as all other autism screening and diagnostic tools were developed based primarily on the male autism phenotype given higher prevalence of autism in males compared to females. As a result, there is currently debate within the field about whether current diagnostic tools are less sensitive to the female phenotype compared to the male phenotype (D’Mello et al, 2022). It is therefore possible that the greater FP rate may be an artifact of missing females who truly are autistic.…”

Sensing echoes: temporal misalignment in auditory brainstem responses as the earliest marker of neurodevelopmental derailment

“…The third set comprised 69 infants with 18 having received the ASD diagnosis and, similarly to the second set, it has a skewness toward males owing to the current deficient pipeline from diagnosis to research ( 26 ). In this set, we do not have information on whether the babies were pre-term or full-term.…”