Functional Disability Among Systemic Sclerosis Patients: Relation to Disease Characteristics and Quality of Life Parameters Abstract: Background: Disability in patients with scleroderma (SSc) has been associated with poor health-related quality of life (HRQoL) in all dimensions, including physical, psychological, and social dimensions. Objective: This study was conducted to examine different factors that may be associated with functional disability and poor HRQoL, with the aim of targeting these factors in the future to improve physical activity, functional outcomes, and HRQoL. Methods: A single-center cross-sectional study was conducted on 38 patients with SSc to compare characteristics between patients with and without disability using the Health Assessment Questionnaire Disability Index (HAQ-DI). Quality of life was assessed using the Short Form-36 (SF-36). Linear regressions were performed to examine variables contributing to functional disability. Results: Almost 65.78% (n = 25) of patients in the study group reported functional disability. The presence of functional disability was associated with reduced HRQoL, as reflected by physical function (P = 0.0001), physical role (P = 0.016), bodily pain (P = 0.001), general health (P = 0.002), social functional (P = 0.002), emotional role (P = 0.042), and mental health (P = 0.025) domains of the SF-36 score. Multiple linear regression indicated that the main predictive factors associated with HAQ-DI were the modified Hand Mobility in Scleroderma, modified Rodnan skin score, DIstance walked in 6 minutes, BOrg dyspnea index, and SAturation of oxygen at 6 minutes (DIBOSA), and Fatigue Severity Scale among patients with SSc. Conclusion: In patients with SSc, recognizing the relationships between clinical findings and functional disability will allow the development of further management strategies to minimize disease severity and enhance HRQoL. Keywords: Functional disability, systemic sclerosis, quality of life, disease characteristics, health-related quality of life (HRQoL), scleroderma.