RT Journal Article
SR Electronic
T1 Further validation of the BILAG disease activity index in patients with systemic lupus erythematosus.
JF Annals of the Rheumatic Diseases
JO Ann Rheum Dis
FD BMJ Publishing Group Ltd and European League Against Rheumatism
SP 756
OP 760
DO 10.1136/ard.55.10.756
VO 55
IS 10
A1 T Stoll
A1 G Stucki
A1 J Malik
A1 S Pyke
A1 D A Isenberg
YR 1996
UL http://ard.bmj.com/content/55/10/756.abstract
AB OBJECTIVE: To examine the association among the BILAG disease activity index components and their relations with global assessments, health status, and laboratory tests with regard to the validity of the BILAG index. METHODS: A cross sectional study of consecutive patients with systemic lupus erythematosus (SLE) attending a specialist lupus outpatient clinic between July 1994 and February 1995. The internal consistency of the British Isles Lupus Assessment Group (BILAG) index-a disease activity assessment system for SLE patients, based on the principle of the physician's intention to treat-was examined using Cronbach's coefficient alpha. The association of the components of the BILAG index with health status as measured with the MOS Short Form 20 (SF-20), with patients' and doctors' global assessments of patient wellbeing and with laboratory tests was analysed with Spearman rank correlations. RESULTS: 133 female and eight male patients, age 20.1 to 88.7 years (mean 41.1, SD 12.5), were included. With few exceptions, the components of the BILAG index which reflect disease activity in different organ systems were not associated with each other. With the exception of the mucocutaneous component, we found a significant relation between all components of BILAG and global assessment of patient wellbeing, health status, erythrocyte sedimentation rate, or serum C3 level. CONCLUSIONS: The study confirms the validity of all but the mucocutaneous component of the BILAG index. However, disease activity in different organ systems in SLE does not follow a common pattern. Thus the individual BILAG components should be used rather than the total BILAG score as a primary endpoint in clinical and epidemiological studies. To capture the total effect of SLE on an individual measures of disease activity, damage, and health status are all needed.