Validity, reliability, and sensitivity-to-change properties of the psoriatic arthritis screening and evaluation...

Psoriatic arthritis (PsA) is an inflammatory arthritis associated with irreversible joint damage in a subset of individuals. There is a need to screen early for this condition to prevent damage. To meet this need, we have developed the psoriatic arthritis screening and evaluation (PASE) questionnaire. The 15-item PASE questionnaire was administered to 190 individuals with either psoriasis or PsA. The PASE questionnaire was readministered to a subset of individuals with PsA in order to assess test-retest reliability and sensitivity-to-change. Receiver operator curves were constructed to optimize sensitivity and specificity for the diagnosis of PsA. Of the 190 participating in the study, 19.5% (37/191) participants were diagnosed with PsA. PASE total scores ranged from 15 to 74 (possible range, 15-75). The PsA group had a median Total score of 51 (25th and 75th percentile 44 and 57), and non-PsA group had a median total score of 34 (25th and 75th percentile 21 and 49) (p < 0.001). A PASE total score of 44 was able to distinguish PsA from non-PsA participants with 76% sensitivity and 76% specificity. Furthermore, 13 of the 15 items demonstrated significant test-retest reliability as assessed by Pearson correlation coefficient (r >or= 0.5). PASE was sensitive-to-change with therapy; PASE scores were significantly lower for PsA individuals after systemic therapy (p < 0.034). The PASE questionnaire is a valid and reliable tool to screen for active PsA among individuals with psoriasis. PASE scores may be used as a marker of therapeutic response.