Validation and reliability of a disease-specific quality-of-life measure in patients with cutaneous lupus erythematosus

Background: Cutaneous lupus erythematosus (CLE) is a potentially disfiguring, chronic autoimmune disease with variable skin manifestations, negatively affecting patients’ quality of life (QoL). Patient-reported outcome (PRO) measures assessing QoL in patients with CLE have been generic or developed without input from patients. Objectives: To demonstrate the reliability and validity of a disease-specific QoL measure for CLE – the cutaneous lupus erythematosus quality of life (CLEQoL). Methods: One hundred and one patients with CLE were recruited, and each patient was asked to complete the CLEQoL. Internal consistency was used as a measure of reliability. Validity was measured in two ways – structural validity via exploratory factor analysis and convergent validity via Spearman correlations between CLEQoL and the Short Form 36 (SF-36), visual analogue scales and clinical variables. Patient demographic and disease characteristics were collected. Results: The mean ± SD age of patients with CLE was 48 ± 13 years, with discoid lupus (n = 72; 71.3%) being the most predominant CLE subtype. Patients were mostly female (n = 88; 87·1%) and African American/Black (n = 59; 58·4%). Internal consistency ranged from 0·67 to 0·97. Five domains (functioning, emotions, symptoms, body image/cosmetic effects and photosensitivity) were extracted with a total explained variance of 71·1%. CLEQoL-related domains correlated with SF-36 domains (r range –0·39 to –0·65). Conclusions: The CLEQoL was found to be a valid and reliable PRO measure for assessing QoL in patients with CLE. Demonstrating that the CLEQoL has strong psychometric properties is an important step towards the development of a disease-specific PRO measure that future clinical trials can use.