Use of Consensus Methodology to Determine Candidate Items for Systemic Lupus Erythematosus Classification Criteria

Objective Given the complexity and heterogeneity of systemic lupus erythematosus (SLE), high performing classification criteria are critical to advancing research and clinical care. A collaborative effort by EULAR and ACR was undertaken to generate candidate criteria, and then to reduce them to a smaller set. The objective of the current study was to select a set of criteria that maximizes the likelihood of accurate classification of SLE, particularly early disease. Methods An independent panel of international SLE experts and the SLE classification criteria steering committee (conducting SLE research in Canada, Mexico, United States, Austria, Germany, Greece, France, Italy, and Spain) ranked 43 candidate criteria. A consensus meeting using nominal group technique (NGT) was conducted to reduce the list of criteria for consideration. Results The expert panel NGT exercise reduced the candidate criteria for SLE classification from 43 to 21. The panel distinguished potential “entry criteria”, which would be required for classification, from potential “additive criteria”. Potential entry criteria were ‘ANA ≥1:80 (HEp 2 immunofluorescence)’ and ‘low C3 and/or low C4.’ The use of low complement as an entry criterion was considered potentially useful in cases with negative ANA. Potential additive criteria include: lupus nephritis by renal biopsy, autoantibodies, cytopenias, acute and chronic cutaneous lupus, alopecia, arthritis, serositis, oral mucosal lesions, CNS manifestations and fever. Conclusion The NGT exercise resulted in 21 candidate SLE classification criteria. The next phases of SLE classification criteria development will require refinement of criteria definitions, evaluation of the ability to cluster criteria into domains and evaluation of weighting of criteria.