Generation of a core set of items to develop classification criteria for scleroderma renal crisis (SRC) using consensus methodology

Abstract

Background: Scleroderma Renal Crisis (SRC) is characterized by malignant hypertension and acute kidney injury. The absence of a gold standard or classification criteria for SRC has hindered research in this field. The Scleroderma Clinical Trials Consortium (SCTC) SRC Working Group was created to develop consensus and data-driven classification criteria for SRC. This project was undertaken to generate a core set of items using consensus methodology to be considered in the development of classification criteria for SRC. Methods: A survey using items identified by a scoping review was developed (REDCap platform, Vanderbilt University, Nashville, Tennessee). An international, multidisciplinary panel of experts from the SCTC, European Scleroderma Trials and Research Group (EUSTAR), Canadian Scleroderma Research Group (CSRG), and Australian Scleroderma Interest Group (ASIG) were invited to participate in a 3-round Delphi exercise. In Round 1, participants were asked to identify omissions and clarify ambiguities regarding the items in the survey. In Round 2, participants were asked to rate the validity and feasibility of the items using Likert-type scales ranging from 1-9 (1= very invalid/unfeasible, 5 = uncertain, 9 = very valid/feasible), and to provide comments. In Round 3, participants reviewed the results and comments of Round 2, and were asked to provide final ratings. Items rated as highly valid and feasible (both median scores ≥7) in Round 3 were selected as the provisional core set of items. A nominal group discussion meeting followed the Delphi exercise to achieve final consensus on the core set of items. Results: Overall, 216 experts were invited and 99 from 16 countries agreed to participate in the Delphi exercise. Of the 31 items in the survey, consensus was achieved on 13 items pertaining to hypertension, renal insufficiency, proteinuria and hemolysis. Eleven experts took part in the nominal group discussion, where consensus was achieved for 5 domains: blood pressure, kidney injury, microangiopathic hemolytic anemia, target organ dysfunction, and histopathology. Conclusions: A core set of items defining SRC was identified using consensus methodology. Future data-driven phases of the project are planned to develop classification criteria for SRC.