Psychometric Evaluation of The PROMIS v2.0 Brief Profile Gender-inclusive Sexual Function Domains in Multiple Sclerosis

Background: Sexual difficulties (SDs) are prevalent in multiple sclerosis (MS) yet remain underdiagnosed and undertreated, reflecting limited validated assessment tools. The PROMIS® Sexual Function and Satisfaction (SexFS) Brief Profile v2.0 includes gender-inclusive subscales assessing sexual interest, satisfaction, and orgasmic functioning. Aim: Evaluate the psychometric properties of the SexFS gender-inclusive domains in a sample of adults living with MS. Methods: A population-based cohort of 198 MS individuals completed a cross-sectional survey, of whom 147 reported recent sexual activity (men n= 36; women n= 111). Psychometric evaluation examined data quality (score distribution, floor/ceiling effects), internal consistency (Cronbach α), convergent and divergent validity via Spearman rank-order correlations, and structural validity through factor analyses. Outcomes: Sexual interest, satisfaction with sex life, and orgasmic function. Results: Item responses showed good distributional properties, strong item–total correlations, and high scaling success. Factor analyses supported the original higher-order three-domain SexFS structure with acceptable model fit. Orgasmic function was represented as a unidimensional domain despite minor local estimation instability. Construct validity was supported by expected correlation patterns, including moderate associations with sexual self-efficacy (.32-.53). Internal consistency was strong across domains (α range: .74-.89). Gender effects on the latent sexual function domains were small and non-significant when modelled as exogenous covariates.Clinical implications: Findings support the SexFS gender-inclusive domains as valid and reliable measures in adult men and women living with MS. By enabling gender-inclusive, domain-specific assessment, the SexFS represents an important advance in the MS sexual health literature, allowing meaningful comparison of sexual functioning across genders within the MS population and other disease groups.Strengths and Limitations: The SexFS assesses domain-specific sexual function in MS, including sexual interest regardless of sexual activity. Men were underrepresented in the sample, limiting precision and generalisability of estimates for men with MS. Establishing the psychometric properties of gender-specific SexFS domains is a priority for future research to support comprehensive assessment in MS. Conclusions: Findings support the SexFS gender-inclusive domains as valid and reliable measures in an adult MS sample. Keywords: Multiple sclerosis; Sexual function; Sexual interest; Sexual satisfaction; Orgasm; Patient-reported outcome measures; SexFS