Smoking, delay to diagnosis, older age at diagnosis, female sex and a history of anti-TNF treatment are associated with worse physical function in established PsA.

Our study demonstrates that the feasibility, specificity, and sensitivity of the CASPAR are maintained when adapted for retrospective use to classify an established research cohort.

The PsAID is a reliable, feasible and discriminative measure in patients with PsA. The good responsiveness of the PsAID and strong correlation of individual items with other PROMS represent an opportunity to reduce questionnaire burden for patients in studies and clinical practice.

These results suggest that mortality in our single-center PsA cohort is not significantly different from the general UK population. No increased risk of death was observed in this cohort.