Enhanced surveillance for the detection of psoriatic arthritis in a UK primary care psoriasis population: results from the TUDOR trial.

OBJECTIVES: Our objective was to determine whether early detection of undiagnosed PsA in a primary care psoriasis population improves outcome in physical function at 24 months post-registration. METHODS: A multicentre, prospective, parallel group cluster randomized controlled trial in patients with psoriasis was conducted. Participants with suspected inflammatory arthritis on screening were referred for an assessment of PsA [enhanced surveillance (ES) arm: at baseline, and 12 and 24 months; standard care (SC) arm: at 24 months]. The primary outcome measure was the HAQ Disability Index (HAQ-DI) at 24 months post-registration in participants diagnosed with PsA. RESULTS: A total of 2225 participants across 135 general practitioner practices registered: 1123 allocated to ES and 1102 to SC. The primary analysis population consisted of 87 participants with a positive diagnosis of PsA: 64 in ES, 23 in SC. The adjusted odds ratio (OR) for achieving a HAQ-DI score of 0 at 24 months post-registration in ES compared with SC was 0.64 [95% CI (0.17, 2.38)], and the adjusted OR of achieving a higher (non-zero) HAQ-DI score at 24 months post-registration in ES relative to SC arm was 1.12 (95% CI 0.67, 1.86), indicating no evidence of a difference between the two treatment groups (P = 0.66). CONCLUSION: The trial was underpowered for demonstrating the prespecified treatment effect; in patients with psoriasis there was no evidence that early diagnosis of PsA by ES in primary care changes physical function at 24 months compared with SC. CLINICAL TRIAL REGISTRATION: The TUDOR trial is registered as ISRCTN38877516.