Physicians' assessment of disease activity in SLE is fundamental but challenging. The Systemic Lupus Erythematosus Disease Activity Index (SLEDAI-2K) is one of the most commonly used disease activity indices. Clinical trials experience suggested that the disease activity instruments did not function well on their own, and composite measures were developed to address this issue. This approach has been adopted after learning from clinical trials that the absence of a robust sensitive index is a major flaw when designing a trial. Another issue with clinical trials is the confounding effect of corticosteroids, which to date have been the most effective treatment for the management of lupus. However, unregulated use of corticosteroids in drug trials decrease the investigator's ability to differentiate between the tested drugs and placebo as they appear to enhance response among the placebo arm and thus mask the effect of the tested drug.