Objective: To assess the reliability of SLEDAI-2000 index in routine practice and its ability to capture disease activity as compared to BILAG-2004 index.
Methods: SLE patients from 11 centres were assessed by 2 raters separately in routine practice. Disease activity was assessed using BILAG-2004 and SLEDAI-2000 indices. Level of agreement for items was used to assess the reliability of SLEDAI-2000. Ability to detect disease activity was assessed by determining the number of patients with high activity on BILAG-2004 (overall score A or B) but low SLEDAI-2000 score (< 6) and number of patients with low activity on BILAG-2004 (overall score C, D or E) but high SLEDAI-2000 score (≥ 6). Treatment of these patients were analysed and increase in therapy was used as the gold standard for active disease.
Results: 93 patients (90.3% women, 69.9% Caucasian) were studied: mean age 43.8 years, mean disease duration 10 years. There were 43 patients (46.2%) with a difference in SLEDAI-2000 score between the 2 raters and this difference was ≥ 4 in 19 patients (20.4%). Agreement for each of the items in SLEDAI-2000 was between 81.7 - 100%. 35 patients (37.6%) had high activity on BILAG-2004 but low SLEDAI-2000 score, of which 48.6% had therapy increased. There were only 5 patients (5.4%) with low activity on BILAG-2004 but high SLEDAI-2000 score.
Conclusions: SLEDAI-2000 is a reliable index to assess SLE disease activity but it is less able to detect active disease requiring increased therapy than BILAG-2004 index.
- disease activity
- inter-rater reliability
- systemic lupus erythematosus