Items for developing revised classification criteria in systemic sclerosis: Results of a consensus exercise

Objective: Classification criteria for systemic sclerosis (SSc; scleroderma) are being updated. Our objective was to select a set of items potentially useful for the classification of SSc using consensus procedures, including the Delphi and nominal group techniques (NGT).

Methods: Items were identified through 2 independent consensus exercises performed by the Scleroderma Clinical Trials Consortium and the European League Against Rheumatism Scleroderma Trials and Research Group. The first-round items from both exercises were collated and redundancies were removed, leaving 168 items. A 3-round Delphi exercise was performed using a 1-9 scale (where 1 = completely inappropriate and 9 = completely appropriate) and a consensus meeting using NGT was conducted. During the last Delphi round, the items were ranked on a 1-10 scale.

Results: In round 1, 106 experts rated the 168 items. Those with a median score of <4 were removed, resulting in a list of 102 items. In round 2, the items were again rated for appropriateness and subjected to a consensus meeting using NGT by European and North American SSc experts (n = 16), resulting in 23 items. In round 3, SSc experts (n = 26) then individually scored each of the 23 items in a last Delphi round using an appropriateness score (1-9) and ranking their 10 most appropriate items for the classification of SSc. Presence of skin thickening, SSc-specific autoantibodies, abnormal nailfold capillary pattern, and Raynaud's phenomenon ranked highest in the final list that also included items indicating internal organ involvement.

Conclusion: The Delphi exercise and NGT resulted in a set of 23 items for the classification of SSc that will be assessed for their discriminative properties in a prospective study.