Objectives To derive and validate a definition of low disease activity (LDA) for SLE based on the SLE Disease Activity Score (SLE-DAS), in a real-life multicentre cohort of SLE patients. Methods Derivation was conducted using data from a monocentric cohort of SLE (Portugal), and validation was performed in a multicentre cohort (Italy, France and Spain). The Lupus Low Disease Activity State (LLDAS) was used as c...