Comparison of responsiveness of BILAG-2004, SLEDAI-2000 and BILAG Systems Tally (BST)

Research output: Contribution to journalArticlepeer-review


  • Chee‐seng Yee
  • David A Isenberg
  • Bridget Griffiths
  • Lee‐suan Teh
  • Ian N Bruce
  • Yasmeen Ahmad
  • Anisur Rahman
  • Athiveeraramapandian Prabu
  • Mohammed Akil
  • Neil Mchugh
  • Christopher J. Edwards
  • David D’cruz
  • Munther A Khamashta
  • Vernon T Farewell

Colleges, School and Institutes

External organisations

  • Doncaster and Bassetlaw Teaching Hospitals NHS Foundation Trust Doncaster UK
  • Head Injury Management Research Group, Faculty of Clinical and Biomedical Science, School of Dentistry, University of Central Lancashire, Preston, UK.
  • University Of Manchester
  • Betsi Cadwaladr University Health Board
  • Sheffield Teaching Hospitals NHS Foundation Trust
  • Department of Rheumatology, Royal National Hospital for Rheumatic Diseases and Royal United Hospitals Bath NHS Foundation Trust.
  • NIHR Southampton Clinical Research Facility University Hospital Southampton NHS Foundation Trust Southampton UK
  • Louise Coote Lupus Unit Guy’s Hospital London UK
  • King’s College London
  • MRC Biostatistics Unit, Cambridge, UK.


Objective: To compare the responsiveness of BILAG-2004 and SLEDAI-2000 disease activity indices and determine if there was any added value in combining BILAG-2004, BILAG System Tally (BST) or simplified BST (sBST) with SLEDAI-2000.

Methods: This was a multi-centre longitudinal study of SLE patients. Data were collected on BILAG-2004, SLEDAI-2000 and therapy on consecutive assessments in routine practice. The external responsiveness of the indices was assessed by determining the relationship between change in disease activity and change in therapy between two consecutive visits. Comparison of indices and their derivatives was performed by assessing the main effects of the indices using logistic regression. ROC curves analysis was used to describe the performance of these indices individually and in various combinations and comparisons of AUC were performed.

Results: There were 1414 observations from 347 patients. Both BILAG-2004 and SLEDAI-2000 maintained an independent relationship with change in therapy when compared. There was some improvement in responsiveness when continuous SLEDAI-2000 variables (change in score and score of previous visit) were combined with BILAG-2004 system scores. Dichotomisation of BILAG-2004 or SLEDAI-2000 resulted in poorer performance. BST and sBST had similar responsiveness as the combination of SLEDAI-2000 variables and BILAG-2004 system scores. There was little benefit in combining SLEDAI-2000 with BST or sBST.

Conclusions: The BILAG-2004 index had comparable responsiveness to SLEDAI-2000. There was some benefit in combining both indices. Dichotomisation of BILAG-2004 and SLEDAI-2000 leads to suboptimal performance. BST and sBST performed well on their own; sBST is recommended for its simplicity and clinical meaningfulness.


Original languageEnglish
JournalArthritis Care and Research
Early online date30 Mar 2021
Publication statusE-pub ahead of print - 30 Mar 2021


  • SLEDAI-2000, BILAG-2004, BST, sBST, SLE, Responsiveness, Disease activity, Longitudinal study