Measurement of Care Needs in Youth with VST Congenital Conditions - Variations in sex traits (VST; also known as differences of sex development) are congenital conditions characterized by incongruence between genetic, gonadal, and/or phenotypic sex. Youth with VST often exhibit complex clinical presentations, including atypical genitalia, sexual/urological dysfunction, and fertility impairment. Interdisciplinary care is the standard of care for youth with VST given interrelated medical, mental health, and developmental care challenges which typically demand careful clinical decision-making and clear, coordinated communication between providers and youth. Many VST-related care decisions made during childhood and adolescence have life-long implications for sexual and urogenital functioning, fertility, quality of life, and mental health. Individuals with VST are at heightened risk for experiencing psychological trauma related to their care which often includes frequent genital exams and discussions of highly personal information with multiple care providers. Interdisciplinary care teams currently lack a standardized, youth-attuned means of obtaining information from youth to help guide personalized care and facilitate shared decision-making. There are no validated measures to capture the care preferences, needs, and care-related experiences of youth with VST, or the variations in VST outcomes experienced by common subgroups (e.g., those with/without interdisciplinary care access or neurodevelopmental disability). Therefore, this proposal, which builds on two NIH-funded pilot projects, finalizes the development, calibration, and validation of a VST self-report tool, called the VISTA, to capture youth needs and preferences and the unique stressors they face. AIM 1 expands and refines the pilot VISTA itemset to ensure item coverage, comprehension, and appropriateness for common VST subgroups (i.e., youth with neurodevelopmental disability; youth without interdisciplinary care access). AIM 2 recruits 600 youth and emerging adults (ages 11-26) with a broad range of VST diagnoses, half without interdisciplinary care access. Scale development research procedures, including latent variable modeling and differential item functioning, will produce subscales that function equivalently across youth. Convergent and discriminant validation will be tested with measures of mental health, medical stress/stigma, body image, and patient engagement in shared decision-making. Ecological validity will be evaluated with mixed methods follow-up interviews in a striated subsample of youth. Test-retest reliability will be assessed at one month. In AIM 3, variations in outcome will be examined across care access, geography, and neurodevelopmental conditions through sequential GLM models evaluating the independent and combined effects of the predictors. This proposal represents a critical step towards facilitating improved clinical practice for youth with VST.