Sexual dysfunction in multiple sclerosis: The impact of different MSISQ-19 cut-offs on prevalence and associated risk factors

•Sexual dysfunction prevalence varies according to the instrument and cut-off applied.•Severe involvement of one sexual domain is associated with motor and cognitive function.•Involvement of many sexual domains is associated with age, anxiety and cognitive function.•Cognitive preservation and rehabilitation could aid in presence of sexual dysfunction. Although multiple sclerosis (MS) Intimacy and Sexuality Questionnaire-19 (MSISQ-19) is a widely applied tool, no unique definition of sexual dysfunction (SD) based on its score exists. To explore the impact of different MSISQ-19 cut-offs on SD prevalence and associated risk factors, providing relevant information for its application in research and clinical settings. After defining SD according to two different MSISQ-19 cut-offs in 1155 people with MS (pwMS), we evaluated SD prevalence and association with sociodemographic and clinical features, mood status and disability via logistic regression. Depending on the chosen cut-off, 45% to 54% of pwMS reported SD. SD defined as MSISQ-19 score >30 was predicted by age (OR=1.01, p=0.047), cognition (OR=0.96, p=0.004) and anxiety (OR=1.03, p=0.019). SD defined as a score >3 on any MSISQ-19 item was predicted by motor disability (OR=1.12, p=0.003) and cognition (OR= 0.96, p=0.002). Applying different MSISQ-19 cut-offs influences both the estimated prevalence and the identification of risk factors for SD, a finding that should be considered during study planning and data interpretation. Preserved cognition exerts a protective effect towards SD regardless from the specific study setting, representing a key point for the implementation of preventive and therapeutic strategies.