3 INDEXES FOR ASSESSING DISEASE-ACTIVITY IN SLE - APPLICATION IN RETROSPECTIVE STUDIES ON ACTIVITY AND COURSE

Generally accepted criteria for evaluating disease activity in systemi c lupus erythematosus (SLE) have not yet been established. At present three indices are widely used: SLAM, BILAG, and SLEDAI. Validity and r eliability have been investigated mostly prospectively. Only a few inv estigations on their suitability for retrospective assessment of disea se activity and of the course of the disease have been performed. We a pplied these three instruments in a retrospective study of disease act ivity in 52 SLE patients. They were found to have a high convergent va lidity (r = 0.91 to 0.74) and to correlate well with the clinician's d ecision concerning treatment intensity (r = 0.81 to 0.72). Their corre lation with immunological parameters were only partially significant. Additionally, the course of the disease was evaluated retrospectively on 3 occasions over 6 months in 30 patients. Sensitivity in detecting changes was determined by the ratio of mean change and standard deviat ion of change (''Standardized Response Mean''/SRM). The SLAM was found to be significantly more sensitive in both the early phase (8 weeks) of observation (SRM = 0.88) and over the entire period (6 months: SRM = 0.93) than either BILAG (SRM = 0.47; 0.64) or SLEDAI (SRM = 0.46; 0. 64). Based on its favourable combination of high validity and sensitiv ity, the SLAM appears to be especially well suited as a standard metho d in retrospective studies on SLE activity and course.