A Nordic study that followed 434 patients with juvenile idiopathic arthritis for 18 years found that 41 patients (9.4%) fulfilled CASPAR criteria at follow-up compared with 28 patients (6.5%) who met International League of Associations for Rheumatology criteria.

The research, published in ACR Open Rheumatology, documented that patients with wrist involvement showed a 3.3 times higher risk of developing psoriatic arthritis (PsA) (P = .02), whereas those with subtalar joint involvement demonstrated a 12.9 times higher risk (P = 0.01).

Statistical analysis showed dactylitis at disease onset had an odds ratio (OR) of 43.4 (P < .001). Presence of psoriasis showed an OR of 20.2 (P < .001), and nail abnormalities showed an OR of 11.6 (P = .002).

The research included patients from Denmark, Finland, Norway, and Sweden with disease onset from 1997 to 2000. The investigators collected clinical, laboratory, and heredity data throughout the follow-up period.

Family history of psoriasis in both first- and second-degree relatives showed an OR of 10.3 (P = .002). Current International League of Associations for Rheumatology (ILAR) criteria do not include second-degree heredity in classification considerations.

The study did not include radiographic data at the 18-year follow-up point. The investigators noted this limitation could have affected identification of patients fulfilling CASPAR criteria through new bone formation evidence.

The investigators reported a need for additional studies on CASPAR criteria utility in patients with juvenile idiopathic arthritis.

Conflict of interest disclosures can be found in the study.