Tradução para o Português-Brasileiro e validação do escore de atividade do lúpus eritematoso sistêmico - Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS)

Abstract

Background: In recent years, several indices for measuring disease activity in Systemic Lupus Erythematosus (SLE) have been proposed. The Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) is a recently published index that has shown a high correlation with other indices and greater predictive power to detect clinically significant changes compared to the SLEDAI-2K. It has 17 weighted items, with 4 continuous variables (arthritis, proteinuria, leukopenia and thrombocytopenia). The proposed cutoff points to establish disease activity levels, scored by an online calculator, are: remission ≤2.08, 2.09≤ mild activity ≤7.64, and moderate/severe activity >7.64. For a health measurement instrument to be widely used in a language and population other than the original, it must be translated/adapted and have its measurement properties validated for the new population where it will be applied. Objective: This multicenter study aimed to translate and adapt the SLE-DAS into Brazilian-Portuguese and evaluate the measurement properties, including feasibility, of this new version. Methods: This is a multicenter, cross-sectional, test-retest study. A total of 365 patients ≥18 years old, from three tertiary centers in Brazil, who met SLICC/2012 and/or ACR-EULAR/2019 classification criteria for SLE were included. Six patients were excluded as they didn’t present the necessary exams to complete the score. The translation process followed published guidelines, including forward translation, backward-translation, comittee discussion and pretesting. Reliability of the new version of the SLE-DAS in Brazilian Portuguese (SLE-DAS Pt-BR) was tested using type 2.1 intraclass correlation coefficient (ICC2.1) and measurement error was assessed by calculating the standard error of measurement and the minimum detectable difference. Construct validity analyses followed specified hypotheses of correlation/association of SLE-DAS Pt-BR with SLEDAI-2K using Spearman correlation (rho) and percentage of agreement with chi-square test, and association between the definitions of remission and low disease activity based on SLE-DAS with the DORIS (Definitions Of Remission In SLE) and LLDAS (Lupus Low Disease Activity State) definitions using percentage of agreement with chi-square test. Criterion validity was investigated through Spearman correlation between SLE-DAS Pt-BR and Physician Global Assessment (PGA). Sensitivity, specificity and accuracy values were found for each SLE-DAS Pt-BR cutoff point using PGA as gold-standard (remission ≤0.4, 0.5≤ mild activity ≤1.0, and moderate/severe activity >1.1). Results: The mean (SD) age was 44.5 (14.0) years, 92.9% female sex, and self-reported race/skin color was 17.8% black, 24.4% brown, 57.3% white, and 1.6% others. The majority (57.3%) were in remission according to SLE-DAS Pt-BR. An excellent intra and inter-rater reliability was observed (ICC2.1= 0.999 and 0.945, respectively). There was a positive, strong (rho =+0.895, p<0.001) correlation between SLE-DAS Pt-BR and SLEDAI-2K. Among individuals classified as in remission and in moderate/severe activity according to SLEDAI-2K, the majority were also in those categories according to SLE-DAS Pt-BR (99.2% and 69.8%, respectively). However, considering mild activity using SLEDAI-2K, only 18.4% were classified in this same category using the SLE-DAS Pt-BR. Most patients considered in DORIS remission and LLDAS were also in remission and in low disease activity by SLE-DAS Pt-BR. There was a positive, strong (rho =+0.861, p<0.001) correlation between the SLE-DAS Pt-BR and PGA. Sensitivity, specificity and accuracy are above 90% for remission and moderate/severe disease activity and above 80% for mild disease activity. Mean (SD) time to complete SLE-DAS Pt-BR after routine clinical evaluation was 59.4 (23.5) seconds. Conclusion: The present study demonstrated that the SLE-DAS Pt-BR version is valid and capable of measuring disease activity in SLE in a sample of Brazilian patients from three reference centers, and can be effectively used in clinical practice to monitor patients with SLE.