OBJECTIVES To characterize the patient (pt) group classified by physicians as having “moderate-to-severe” systemic lupus erythematosus (SLE) disease severity, and assess disease burden. METHODS Data were extracted from the Adelphi 2013 Lupus Disease-Specific Program, a multinational survey of clinical practice. Physicians completed Patient Record Forms (PRFs); pts self-reported data including EQ-5D and the Work Productivity and Activity Impairment Index for SLE (WPAI-Lupus) in Patient Self-Completion Records (PSCs). Pt eligibility was determined by physicians; disease activity and severity were based on physician assessment. Data across countries were pooled. RESULTS Data were collected from rheumatologists in the USA (n=97), France (n=37) and Germany (n=35), including PRFs (550/200/207, respectively) and PSCs (303/109/149, respectively). Physician assessment of disease severity was predominantly based on affected organs and symptoms (45% and 35% of rheumatologists, respectively); 15% based severity on test results/clinical assessments. No disease activity index was widely used, 58% used their own assessment. Physician assessment of severity was imperfectly correlated with control of disease activity (activity controlled in 56.1% of “moderate-to-severe” pts, uncontrolled in 6.1% of “mild” pts). Pts with “moderate-to-severe” severity presented with greater severity and organ involvement, and a higher proportion experienced flares per 12-month period than “mild” pts (78.4% vs 52.6%). “Moderate-to-severe” severity was associated with a greater impact on HRQoL (EQ-5D: 0.72 vs 0.86; WPAI: 35.0 vs 16.3) than “mild” disease. Fewer “moderate-to-severe” pts were employed (full-time employment: 35.8% vs 48.8%), and a higher proportion required a care provider (6.6% vs 3.3%). CONCLUSIONS SLE severity is not consistently assessed or defined in clinical practice: measures used in clinical trials are not routinely adopted in daily practice, whilst organ involvement and symptoms are central to physician assessment of severity. Correlation between severity and control of disease activity is imperfect. “Moderate-to-severe” severity is associated with a greater burden than “mild” disease.