The BILAG-2004 index is sensitive to change for assessment of SLE disease activity.
OBJECTIVE
To determine if the BILAG-2004 index is sensitive to change for assessment of SLE disease activity.


METHODS
This was a prospective multi-centre longitudinal study of SLE patients. At every assessment, data were collected on disease activity (BILAG-2004 index) and treatment. Analyses were performed using overall BILAG-2004 index score (as determined by the highest score achieved by any of the individual systems) and all the systems scores. Sensitivity to change was assessed by determining the relationship between change in disease activity and change in therapy between two consecutive visits. Statistical analyses were performed using multinomial logistic regression.


RESULTS
There were 1761 assessments from 347 SLE patients that contributed 1414 observations for analysis. An increase in therapy between visits occurred in 22.7% observations, while 37.3% had a decrease in therapy and in 40.0% therapy was unchanged. Increase in overall BILAG-2004 index score was associated with increase in therapy and inversely associated with decrease in therapy. Decrease in overall BILAG-2004 index score was associated with decrease in therapy and was inversely associated with increase in therapy. Changes in overall BILAG-2004 index score were differentially related to change in therapy, with greater change in score having greater predictive power. Increase in the scores of most systems was independently associated with an increase in treatment and there was no significant association between decreases in the score of any system with an increase in therapy.


CONCLUSIONS
The BILAG-2004 index is sensitive to change and is suitable for use in longitudinal studies of SLE.
Yee
Chee-Seng
CS
Rheumatology Research Group, University of Birmingham, Birmingham, UK. csyee@ymail.com
Farewell
Vernon
V
Isenberg
David A
DA
Griffiths
Bridget
B
Teh
Lee-Suan
LS
Bruce
Ian N
IN
Ahmad
Yasmeen
Y
Rahman
Anisur
A
Prabu
Athiveeraramapandian
A
Akil
Mohammed
M
McHugh
Neil
N
Edwards
Christopher
C
D'Cruz
David
D
Khamashta
Munther A
MA
Maddison
Peter
P
Gordon
Caroline
C
D000328:Adult; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016015:Logistic Models; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy / Q000276:immunology*; D008181:Lupus Nephritis / Q000188:drug therapy / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016896:Treatment Outcome
D007166:Immunosuppressive Agents