Patient reported outcomes in calcium pyrophosphate deposition disease compared to gout and osteoarthritis.

OBJECTIVE: Calcium pyrophosphate deposition (CPPD) disease prevalence is similar to gout and osteoarthritis (OA), yet CPPD outcomes research greatly lags behind these other forms of arthritis. We compared validated patient-reported outcome measures in patients with CPPD versus gout and OA.

METHODS: Patients with CPPD were recruited from Brigham and Women's Hospital, 2018-2022. Presence of CPPD manifestations (acute calcium pyrophosphate [CPP] crystal arthritis, chronic CPP inflammatory arthritis, and/or OA with CPPD) was confirmed by medical record review. Baseline surveys included the Gout Assessment Questionnaire (GAQ 2.0) modified to ask about "pseudogout" rather than "gout", RAPID3, and WOMAC. We compared responses in CPPD patients against published gout and OA cohort studies.

RESULTS: Among 47 CPPD patients, mean age was 71.9 years and 51% were female. 68% had at least 1 episode of acute CPP crystal arthritis, 40% had chronic CPP inflammatory arthritis, and 62% had OA with CPPD. Pain visual analog scale scores during a flare were similar in CPPD (6.8 ± 1.9) and gout (6.7 ± 2.6) (p=0.78). CPPD patients reported significantly greater unmet treatment need than gout patients (p=0.04). RAPID3 scores in CPPD (8.1 ± 5.6) were lower than in gout (12.1 ± 6.2) (p<0.01) and similar to OA (6.8 ± 6.1) (p=0.30). CPPD patients had significantly worse WOMAC stiffness scores than patients with mild OA, and significantly better WOMAC function scores than patients with severe OA.

CONCLUSION: Patients with CPPD may experience pain comparable to gout and OA and reported substantial unmet treatment needs.