The polish validation of a disease-specific patient-reported outcome measure of systemic lupus erythematosus

BackgroundLupusPRO is a disease-targeted, patient-reported outcome measure developed for assessing the quality of life in patients with systemic lupus erythematosus. Initially, the questionnaire was validated among U.S. patients of varied ethnic backgrounds and genders. This study aims to carry out a cross-cultural adaptation and validation of the Polish-translated version of LupusPRO.MethodWe administered the Polish version of LupusPRO along with the 36-Item Short Form Health Survey (SF-36) and EQ-5D-5L questionnaire, and the Polish modification of the Hospital Anxiety and Depression Scale (HADS-M). At the same time, we collected demographics and clinical characteristics. Disease activity, damage, and exacerbation were assessed using SELENA-SLEDAI, SLICC/ACR DI and LFA. Furthermore, we tested internal consistency reliability (measured with Cronbach's alpha), test-retest reliability (using r-Pearson correlation coefficient), convergent validity (against corresponding domains of SF-36) and criterion validity (against disease activity, damage and EQ-VAS), and known group validity.ResultsA total of 199 (91% females) patients with SLE with a mean age of 42.6 ± 12.62 years participated in the study. We observed that the mean SELENA-SLEDAI reached 5.3 (±5.9) points, while SLICC/ACR DI was at 1.3 (±2.0) points. The internal consistency reliability of LupusPRO domains ranged between 0.737 and 0.925 (except for Lupus Symptoms, Social Support, Coping, and Satisfaction with care). For all domains except Social Support, test-retest reliability exceeded 0.7. Convergent validity with corresponding domains of the SF-36 was good (r > 0.5). All health-related quality of life domains performed well against disease activity and damage measures, establishing its criterion validity. Confirmatory factor analysis showed a satisfactory fit. (± expression of range).ConclusionThe Polish version of LupusPRO has proved to have fair psychometric properties among Polish patients with SLE.