Charlotte Jauffret, Tristan Pascart, Emmanuel Chazard
Affiliation(s):
Department of Rheumatology, Saint-Philibert Hospital, Lille Catholic University, Lille, France
Introduction: Calcium pyrophosphate crystal deposition (CPPD) disease is a common but underdiagnosed rheumatic condition, largely due to the polymorphic nature of its chronic phenotype, which often mimics other inflammatory rheumatic diseases [1,2]. We aimed to explore diagnostic pathways, including diagnostic errors and variability, in hospitalized patients with CPPD disease using the French national hospital database (Programme de Médicalisation des Systèmes d’Information, PMSI), in order to identify potential profiles leading to classification errors.
Patients and Methods: We conducted an exploratory retrospective cohort study using the PMSI database, including all adult patients hospitalized between January 2015 and December 2024 who had a principal diagnosis of CPPD disease (ICD-10 codes M11.1* or M11.2*) during a hospital stay. Only the first eligible hospitalization was considered as the index stay. Demographic characteristics, hospitalization data, procedures, and rheumatologic co-diagnoses recorded before, during, and after the index stay were descriptively analyzed.
Results: A total of 46,450 patients with an index stay were included. The follow-up period was 10 years, corresponding to the available data period. During the index stay, the most frequent associated diagnoses recorded alongside CPPD disease were osteoarthritis (18.0%), unspecified arthritis (6.7%), gout (2.7%), polymyalgia rheumatica (0.8%), and rheumatoid arthritis (0.8%). Associated rheumatologic diagnoses were recorded in 8.2% of patients before the index stay, 26.7% during the index stay, and 6.8% after the index stay. The median time to diagnostic variability was 306 days before and 391 days after the index stay. Following an index stay coded for CPPD disease, the rheumatologic diagnosis most rapidly associated was polymyalgia rheumatica.
Conclusion: Diagnostic instability associated with CPPD disease is frequent, particularly with polymyalgia rheumatica, rheumatoid arthritis, gout, and osteoarthritis. These findings highlight the need for increased vigilance during the diagnostic evaluation period in order to improve patient care pathways and ensure the earliest effective management.
References:
[1] Pascart T, Filippou G, Lioté F, Sirotti S, Jauffret C, Abhishek A. Calcium pyrophosphate deposition disease. Lancet Rheumatol. 2024 Nov;6(11):e791-e804. doi: 10.1016/S2665-9913(24)00122-X
[2] Jauffret C, Tedeschi SK, Abhishek A, Latourte A, Filippou G, Neogi T, Pascart T. Calcium pyrophosphate crystal deposition: 2025 update to recent epidemiological findings. Curr Opin Rheumatol. 2025 Aug 4. doi: 10.1097/BOR.0000000000001117.