Study of Flare Assessment in Systemic Lupus Erythematosus Based on Paper Patients

OBJECTIVE: To determine the level of agreement of disease flare severity (distinguishing severe, moderate and mild flare and persistent disease activity) in a large paper patient exercise involving 988 individual cases of systemic lupus erythematosus. METHODS: 988 individual lupus case histories were assessed by three individual physicians. Complete agreement about the degree of flare (or persistent disease activity) was obtained in 451 cases (46%) and these provided the reference standard for the second part of the study. This component utilised three flare activity instruments (BILAG 2004, SELENA flare index (SFI) and the revised SELENA flare index (rSFI)). The 451 patient case histories were distributed to 18 pairs of physicians being carefully randomised in a manner designed to ensure a fair case mix and equal distribution of flare according to severity. RESULTS: The three physician assessment of flare matched the level of flare using the three indices thus 67% for BILAG 2004, 72% for SFI and 70% for rSFI. The corresponding weighted kappas for each instrument were 0.82, 0.59 and 0.74 respectively. We undertook a detailed analysis of the discrepant cases and several factors emerged including a tendency to score moderate flares as severe and persistent activity as flare especially when the SFI and rSFI instruments were used. Overscoring was also driven by scoring treatment change as flare even if there were no new or worsening clinical features. CONCLUSIONS: Given the complexity of assessing lupus flare, we were encouraged by the overall results reported. However the problem of capturing lupus flare accurately is not completely solved