Psychometric validation and reliability of the Arabic version of the LupusQoL questionnaire (Ar-LupusQoL) in Egyptian patients with systemic lupus erythematosus

Abstract

Introduction Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease associated with impaired health-related quality of life (HRQoL). The LupusQoL is a disease-specific instrument designed to capture SLE-related HRQoL domains; however, a validated Arabic version remains unavailable. Objective To evaluate the reliability and validity of the Arabic version of LupusQoL (Ar-LupusQoL) in SLE Egyptian patients. Methods In this multicenter cross-sectional study, 156 patients with SLE completed the Arabic LupusQoL and Short Form-36 (SF-36). Disease activity and damage were assessed using Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR-DI), respectively. Internal consistency was assessed using Cronbach’s alpha, and test–retest reliability using intraclass correlation coefficients. Construct validity was examined through item–total correlations and correlations with corresponding SF-36 domains. Discriminant validity was also evaluated. Results The mean age was 33.37 ± 10.71 years, and 98.1% were female. The cohort demonstrated a high level of disease activity (87.2% with SLEDAI >4; mean SLEDAI 19.52 ± 16.20). Internal consistency was high across domains (α = 0.78–0.98). Item–total correlations were strong (r > 0.30, p < 0.001). Significant correlations with corresponding SF-36 domains supported convergent validity (r = 0.668–0.829, p < 0.05). The Ar-LupusQoL effectively discriminated between active and inactive disease ( p < 0.001). Ceiling effects were observed in selected domains, with no significant floor effects. Conclusion The Arabic version of the LupusQoL is a reliable and valid instrument for assessing HRQoL in Egyptian patients with SLE. The high disease activity observed, likely reflecting recruitment from tertiary referral centers, may limit generalizability to patients with milder disease.