Advancing the understanding of autistic women and girls: Development of a screening tool to improve recognition and access to diagnostic pathways and support

Delayed, missed or misdiagnosis of autism in women and girls is an ongoing concern worldwide, which has potentially life altering consequences on a person's mental health and quality of life. Autism is often thought of as a predominantly male condition and as such, has shaped the way in which we have come to understand autism over the years. Despite increasing evidence into the potentially more subtle differences between males and females, there is still a lack of transference of this knowledge to the general population and wider clinical settings. The purpose of this thesis was to design a screening tool that may be better at identifying autism in women and girls, that will in future aim to improve access to diagnostic pathways and reduce missed or misdiagnosis. Four related studies were conducted which led to the development and refinement of the Female Autism Spectrum Screening Tool (FASST).

Stage 1 of the research was to systematically examine and synthesise the existing research literature to determine what was known about the experiences and behavioural presentations of autistic women and girls. More specifically, the review aimed to identify areas of difference between males and females that could be used to develop specific items in a new screening tool that may be helpful in screening for autism in women and girls. Conflicting evidence was found for social and communication difficulties, with some studies finding equal levels of difficulty for autistic males and females, while others reported fewer difficulties for autistic females. More lifetime sensory issues were found for females compared to men, while RRBI were seen more frequently in males than females. In relation to camouflaging, again the research was conflicting, with some studies suggesting females engaged in more camouflaging than males, with some reporting no differences. Experiences related to diagnosis, mental health, social relationships and a lack of general support were reported. A total of 17 new items were added to the FASST post systematic review.

Stage 2 of the research involved two development studies. The overall aim was to assess the item content of the FASST using Focus Group and Delphi methodologies in order to prepare the FASST for testing in the pilot stage of study 3. Four focus groups were conducted which led to the amendment of 16 original FASST items and the addition of 18 new items. A total of 83 items were then sent to the Delphi consultation, where a panel of autistic people and key stakeholders were asked to rate the importance of each item. Both the focus group and the Delphi methodology resulted in a final version of the FASST which incorporated 58 items.

Stage 3 involved the piloting of the refined FASST. The overall aim of this study was to conduct preliminary evaluations of the FASST's psychometric properties. The FASST demonstrated excellent internal consistency and Test re-test reliability. The FASST demonstrated a robust capacity to discriminate between autistic and non-autistic women, with significant differences found between groups.

The following conclusions were drawn from the combined studies included within this thesis. First, it can be concluded that the FASST is able to successfully identify autism in females. Preliminary evidence suggests that the FASST is psychometrically robust and is likely a useful resource for future use clinically in front line services such as GP's and mental health teams, as well as for use in future research. While there is evidence to suggest that autism presents differently in women and girls, most of the research remains contradictory. Despite this, the research conducted within this thesis has ensured that the evidence base is synthesised which is important for future dissemination to improve awareness of the differences that autistic women and girls might present with. Second, to the best of our knowledge, this is the first screening tool that has been developed with detailed input from autistic people and key stakeholders. The use of various research methodologies throughout this thesis ensured that the lived experiences of autistic people were explored to develop a screening tool that will potentially reduce the number of incorrect referrals as well as reducing misdiagnosis in the future.