Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease that manifests with a myriad of clinical and laboratory features. The assessment of SLE is comprehensive and includes different core set domains; disease activity, damage, health-related quality of life, adverse events and economic impact. This comprehensive book is focused on the instruments and outcome measures utilized in the assessment of SLE. It targets different audiences including physicians, scientists/researchers and different health professionals interested in learning about the art of measurement in SLE. The book highlights the importance of measurement in the assessment of SLE in a clinical settings, research and clinical trials. Each of the chapters provide a systematic approach to the instruments utilized in the assessment of a specific construct in SLE (e.g., disease activity, fatigue, etc.) and incorporate a comprehensive coverage of disease specific and disease generic measures. It also discusses different patient-reported outcomes that are crucial to reflect patient perceptions of their health condition and cover constructs such as fatigue, pain, anxiety and depression, cognition, frailty, and many others.