Petri M et al. – The new Systemic Lupus Collaborating Clinics (SLICC) classification criteria performed well on a large set of patient scenarios rated by experts. They require that at least one clinical criterion and one immunologic criterion be present for a classification of SLE. Biopsy confirmed nephritis compatible with lupus (in the presence of SLE autoantibodies) is sufficient for classification.Methods
- The classification criteria were derived from a set of 702 expert–rated patient scenarios.
- Recursive partitioning was used to derive an initial rule that was simplified and refined based on SLICC physician consensus.
- SLICC validated the classification criteria in a new validation sample of 690 SLE patients and controls.
- Seventeen criteria were identified.
- The SLICC criteria for SLE classification requires: 1) Fulfillment of at least four criteria, with at least one clinical criterion AND one immunologic criterion OR 2) Lupus nephritis as the sole clinical criterion in the presence of ANA or anti–dsDNA antibodies.
- In the derivation set, the SLICC classification criteria resulted in fewer misclassifications than the current ACR classification criteria (49 versus 70, p=0.0082), had greater sensitivity (94% versus 86%, p<0.0001) and equal specificity (92% versus 93%, p=0.39).
- In the validation set, the SLICC Classification criteria resulted in fewer misclassifications (62 versus 74, p=0.24), had greater sensitivity (97% versus 83%, p<0.0001) but less specificity (84% versus 96%, p<0.0001).