Criteria for the classification of systemic lupus erythematosus (SLE)
are not sufficient to describe the degree of disease activity. Several
instruments to assess disease activity have been developed. This chap
ter reviews the derivation, validation, and clinical application of cu
rrent disease activity measures in SLE, as well as comparison among th
em. As patients with lupus survive longer, the sequelae of the disease
activity and its therapy are becoming more common. The derivation and
validation of the single, generally accepted SLICC/ACR damage index i
s also discussed.