Health-Related Quality of Life in Primary Sjögren's Syndrome: Oral Manifestations and Patient-Reported Outcomes

Background/Objectives: Primary Sjögren's syndrome (pSS) is a chronic autoimmune rheumatic disease that clinically presents with symptoms of xerostomia and xerophthalmia, as well as a wide range of other symptoms that may affect patients' daily functioning and life satisfaction. The main purpose of this study was to assess their health-related quality of life (HRQoL) using both general and disease-specific questionnaires. Methods: This cross-sectional observational research with prospective data collection was conducted at the Rheumatology Clinic of the University Clinical Centre of Kragujevac. Participants were divided into two groups: patients with oral manifestations (oral manifestations group) and those presenting with xerostomia only, without other oral lesions or symptoms (xerostomia-only group). A complete clinical examination of the patient's oral cavity was performed by one doctor of dental medicine. HRQoL was evaluated using various generic and disease-specific instruments. Results: A total of 80 participants were included in the study, of whom 40 were in the oral manifestations group and 40 in the xerostomia-only group. Patients with oral manifestations had significantly higher scores across all PSS-QoL domains compared with the xerostomia-only group (p < 0.001). A statistically significant difference in the total EQ-5D result was detected between groups (0.7 (0.3) vs. 0.8 (0.1), p < 0.001). In multivariable regression analysis (R² = 0.921), the ESSPRI score (β = 0.418, p < 0.001) and the presence of oral manifestations (β = -1.155, p < 0.001) were significant independent predictors of impaired HRQoL, while disease activity showed no significant association (p = 0.895). Conclusions: Patients with primary Sjögren's syndrome presenting with oral manifestations have poorer HRQoL compared with participants with xerostomia only. Symptom burden, including dryness, pain, fatigue, and oral manifestations, may be associated with decreased HRQoL, in contrast to disease activity.