Validation of the Spanish Version of the PURE-4 Questionnaire for the Early Detection of Psoriatic Arthritis in Psoriatic Patients

Abstract

Background and objective: Psoriasis often precedes the onset of psoriatic arthritis (PsA), so dermatologists often face the challenge of early identifying signs of PsA in patients with psoriasis. Our aim was to validate the Spanish version of the PURE-4 questionnaire as a screening tool for PsA, evaluate its performance in terms of sensitivity, specificity, feasibility, reliability, and build validity.

Methods: This was a cross-sectional, observational, multicenter trial of adult patients with psoriasis. Initially, patients were assessed by a dermatologist and completed 2 self-administered versions (in print and online) of the PURE-4 questionnaire. Afterwards, the rheumatologist, blinded to the PURE-4 results, assessed the presence/absence of PsA, being the reference to determine the performance of the PURE-4 questionnaire.

Results: A total of 268 patients were included (115 [42.9%] women; mean age, 47.1±12.6). The prevalence of PsA according to rheumatologist diagnosis was 12.7% (34 patients). The mean PURE-4 score for patients with psoriasis diagnosed with PsA was 2.3±1.1, and 1.3±1.3 for patients without PsA (P<.001). The cutoff value ≥2 demonstrated the best performance for detecting PsA, with a negative predictive value of 95.1% (95% confidence interval, 90.3-97.6).

Conclusions: The PURE-4 questionnaire demonstrated good performance in detecting PsA, with an optimal cutoff point ≥2. This simple tool could facilitate early referral of patients to the rheumatology unit.

Keywords: Artritis psoriásica; Cribado; Diagnostic performance; PURE-4; Psoriasis; Psoriatic arthritis; Referral; Remisión; Rendimiento diagnóstico; Screening.