Objectives: The BILAG index is a clinical measure of lupus disease activity. It is valid, reliable and sensitive to change. Scoring in the BILAG index is based upon the physician's intention to treat. A flare of active lupus is defined as a new A or B score in at least one system. The main aim of this study was to determine whether patients with a lupus flare are treated as expected from the principles upon which the scoring system was devised. Secondly we wanted to establish whether patients with a new B score preceded by a C should be considered to have flared, as with patients scoring B following a D or E score.
Methods: Over a 12-month period, 250 patients regularly attending lupus clinics in Birmingham and London were assessed using the BILAG index at each visit.
Results: A new A or B score was observed in 154 (61.6%) patients. An A flare was observed in 26 (10.4%) patients. A B flare (in which the B score was preceded by a D or E score) was observed in 65 (26.0%) patients. There were 63 (25.2%) patients in whom there was a B score in a system in which a C score was previously recorded. Steroids were started or increased in 20 (77%) patients with an A flare. Almost all (92%) patients with a new A score had some increase in therapy. For the patients with new B scores, 53 (41%) had some increase in therapy, but multiple reasons were found for no change in therapy in 75 (59%) of these patients. There was no difference in the treatment of new B scores arising after a previous C score compared with previous D or E scores. Non-Caucasians were more likely to have a lupus flare than Caucasians.
Conclusions: These results are consistent with the principles upon which the BILAG index was devised and suggest that a moderate disease flare can be defined as a new B score following a C, D or E score according to the BILAG index.