Validity and reliability of the Lupus QoL index in Turkish systemic lupus erythematosus patients.

BACKGROUND: Systemic lupus erythematosus (SLE) patients have seriously impaired quality of life (QoL). In addition to activity and damage indices used in the past, tools to evaluate QoL in SLE have been developed in recent years. In this study, we test the validity of the Turkish version of the Lupus-QoL (LupusQoL-TR) score, and investigate its association with clinical findings and activity indices. METHODS: A total of 132 patients diagnosed with SLE according to ACR 1997 criteria were included. The clinical and demographic features, and biochemical data were retrieved from hospital records. SLE Disease Activity Index (SLEDAI) and damage score (SLICC-ACR) were determined at the time of administration of Lupus-QoL questionnaire. The Lupus-QoL includes 34 questions divided into eight domains. We reevaluated the LupusQoL-TR and pretested its understandability. SLE patients were concomitantly administered the LupusQoL-TR and generic SF-36. Internal consistency, test-retest reliability, convergent and discriminant validity were calculated. RESULTS: The mean age of our SLE patients was 37.9 ± 12.8 years. Internal consistency reliability ranged from 0.88 to 0.93, and test-retest reliability from 0.84 to 0.94. LupusQoL-related domains in SF-36 were correlated (from 0.66 to 0.74). Most LupusQoL-TR domains, except planning, were able to discriminate between active and inactive SLE groups. Scores in all domains of the LupusQoL-TR were found to be discriminative for patients with and without damage according to SLICC-ACR score. CONCLUSION: The LupusQoL-TR was found to be a valid patient-reported outcome measure method when evaluating QoL in Turkish SLE patients.

Health-related quality of life assessed by LupusQoL questionnaire and SF-36 in Turkish patients with systemic lupus erythematosus.

The LupusQoL is a disease-specific health-related quality of life (HRQoL) measure for patients with lupus. We conducted this study to compare the efficiency of LupusQoL-TR (validated Turkish version of the LupusQoL questionnaire) with the 36-item Short-Form Health Survey (SF-36), a generic quality of life (QoL) scale, in Turkish patients with lupus. Both questionnaires were conducted at a single visit to the clinic. Disease activity was measured with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Associations between the LupusQoL-TR and SF-36 domains were examined while also examining age, disease duration, and disease activity for each questionnaire. Descriptive statistics, Spearman's correlation coefficients, and Students t test were performed to analyze the data. A total of 113 consecutive patients with lupus (F/M 108:5, mean age 40.6 ± 11.9 years, mean disease duration 8.5 ± 7.0 years) were included, and 69 % of these were active. The median SLEDAI score was 2 (0-24), the mean global LupusQoL-TR score was 60.9 ± 23.3, and the mean SF-36 score was 41.2 ± 9.0. There was a significant correlation between LupusQoL-TR and SF-36 mean scores (r = 0.83; p < 0.001). QoL assessed by LupusQoL-TR and SF-36 did not correlate with disease activity (r = -0.11; p = 0.244 and r = -0.03; p = 0.721, respectively). LupusQoL-TR and SF-36 questionnaires were beneficial instruments in evaluating HRQoL in Turkish lupus patients. However, LupusQoL-TR and SF-36 were not associated with SLEDAI scores, which suggested that QoL might be affected by other factors besides disease activity, especially in clinically inactive or mildly active patients.