Spanish LupusPRO: cross-cultural validation study for lupus

Abstract

Purpose LupusPRO is a disease-targeted, patient-reported, outcome measure that was developed and validated among US patients with systemic lupus erythematosus (SLE). To expand the availability and use of the tool, we undertook a cross-cultural adaptation and validation study of the Spanish-translated version of the LupusPRO. Method Forward and back translations of the 43-item English LupusPRO were undertaken and pretested in five individuals. The finalized Spanish version was administered to 211 SLE patients of Hispanic ancestry from the US and Latin America. Short Form-36 (Spanish) and Spanish LupusPRO were also administered. Disease activity was ascertained using the systemic lupus erythematosus disease activity index. A Spanish LupusPRO questionnaire that could be completed within 2–3 days was mailed to SLE patients of Hispanic ancestry and they mailed it back. Internal consistency reliability, test-retest reliability, criterion validity (against disease activity or health status) and convergent validity were tested. All reported p values are two-tailed. Results A total of 211 Spanish-speaking SLE patients (90% women) participated. Test-retest reliability of LupusPRO domains ranged from 0.80–0.95, while internal consistency reliability of the domains ranged from 0.71–0.96. Convergent validity with corresponding domains of the SF-36 was present. All health-related quality of life domains of the LupusPRO (except procreation) performed well against disease activity measures, establishing its criterion validity. Confirmatory factor analysis showed a good fit. Conclusion The Spanish LupusPRO has fair psychometric properties and is now available to be included in clinical trials and in longitudinal studies for testing of responsiveness to change.