• systemic lupus erythematosus
• disease activity
• outcomes research

The accurate assessment of disease activity in patients with systemic lupus erythematosus (SLE) remains a pending task. Recently, Jesus et al developed and validated a novel instrument, the SLE Disease Activity Score (SLE-DAS), in two representative cohorts of Caucasian patients.1 Through an elegant methodology, the authors demonstrated that SLE-DAS provides a more accurate identification of clinically meaningful changes over time, with higher sensitivity and similar specificity compared with the SLE Disease Activity Index 2000 (SLEDAI-2K). Although these finding have adequate methodological support, there are some points of concern that deserve further clarification. On the one hand, a clinimetric instrument must be validated in populations of different ethnic and geographical substrate before being accepted as of generalised use. On the other hand, the extent of lupus activity does not show a linear distribution in patients from a real-life scenario, so the performance of any instrument should be evaluated in individuals with quiescence or mild disease activity separately from patients with moderate to severe disease activity.

In an attempt to answer these unsolved questions, we conducted a study in our lupus cohort, which is based on a general practice of rheumatology in a …