The French-Canadian validation of a disease-specific, patient-reported outcome measure for lupus

Abstract

Objectives: The objective of this paper is to perform the cross-cultural validation of the French version of the LupusPRO, a disease-targeted patient-reported outcome measure, among systemic lupus erythematosus (SLE) patients in Canada.

Methods: The French version of the LupusPRO and the MOS SF-36 were administered; demographic, clinical and serological characteristics were obtained. Disease activity (SELENA-SLEDAI and the Lupus Foundation of America definition of flare) and damage (SLICC/ACR SDI) were assessed. Physician disease activity and damage assessments were ascertained using visual analog scales. Internal consistency reliability (ICR), test-retest reliability (TRT), convergent and discriminant validity (against corresponding domains of the SF-36), criterion validity (against disease activity, damage or health status) and known group validity were tested.

Results: A total of 99 French-Canadian SLE patients participated (97% women, mean (SD) age 45.2 (14.5) years). The median (IQR) SELENA-SLEDAI and SDI were 3.5 (6.0) and 1.0 (2.0), respectively. The ICR of the LupusPRO domains ranged from 0.81 to 0.93 (except for lupus symptoms, procreation and coping), while TRT ranged from 0.72 to 0.95. Convergent and discriminant validity, criterion validity and known group validity against disease activity, damage and health status measures were observed. Confirmatory factor analysis showed a good fit.

Conclusion: The LupusPRO has fair psychometric properties among French-Canadian patients with SLE.

Keywords: Systemic lupus erythematosus; quality of life; self-assessment.