Core domain set for chronic and/or recurrent manifestations of calcium pyrophosphate deposition disease: OMERACT delphi survey to establish consensus

Objective: To agree on important domains for the Outcome Measures in Rheumatology (OMERACT) core domain set for chronic and/or recurrent manifestations of calcium pyrophosphate deposition (CPPD) disease. Methods: Patient research partners (PRPs) and other participants (mainly clinicians and researchers) contributed to three rounds of a consensus survey using Delphi methodology. Consensus was defined if ≥70% of both patients and other participants scored the domain as ‘critically important domain to include’. In a subsequent ranking exercise, all participants were asked to select and rank up to 10 of the domains reaching consensus. Results: Fifteen domains reached consensus as critically important. Within the Pathophysiological Manifestations area, these were joint pain, joint tenderness, joint swelling, acute CPP crystal arthritis flare, joint damage on imaging tests, joint calcification on imaging tests, and crystals in joint fluid. Within the Life Impact area, these were overall function, ability to complete daily tasks, ability to work, health related quality of life, patient global assessment response to treatment, patient global assessment of disease activity, physician global assessment of disease activity, and patient satisfaction with treatment. No domains within the Societal/Resource Use area reached consensus as critically important. In the ranking exercise, joint pain, joint tenderness, joint swelling, acute CPP crystal arthritis flare and overall function were most highly ranked. Conclusion: This work has identified potential domains for the OMERACT core domain set for chronic and/or recurrent manifestations of CPPD disease. There was strong support for joint pain, joint tenderness, joint swelling, acute CPP crystal arthritis flare, overall function, and global assessments of disease activity as core domains.