PT - JOURNAL ARTICLE AU - Marco Di Carlo AU - Andrea Becciolini AU - Valentina Lato AU - Chiara Crotti AU - Ennio Giulio Favalli AU - Fausto Salaffi TI - The 12-item Psoriatic Arthritis Impact of Disease Questionnaire: Construct Validity, Reliability, and Interpretability in a Clinical Setting AID - 10.3899/jrheum.160924 DP - 2017 Mar 01 TA - The Journal of Rheumatology PG - 279--285 VI - 44 IP - 3 4099 - http://www.jrheum.org/content/44/3/279.short 4100 - http://www.jrheum.org/content/44/3/279.full SO - J Rheumatol2017 Mar 01; 44 AB - Objective. To study, in a real-life setting, the construct validity, the reliability, and the interpretability of the 12-item Psoriatic Arthritis Impact of Disease (PsAID-12) questionnaire in patients with psoriatic arthritis (PsA).Methods. In 144 consecutive patients with PsA (81 men and 63 women, mean age of 51.4 ± 12.8 yrs, and 77 receiving biologic treatment), the PsAID-12 and other patient-reported outcomes (PRO) were collected, such as the Dermatology Life Quality Index. Each patient underwent articular and skin assessment.Results. Construct validity: Factor analysis revealed a 2-factor result defined as the PsAID Symptom Score and the PsAID Skin Score. In determining convergent validity, significant correlations were found between the PsAID-12 and the clinical Disease Activity index for Psoriatic Arthritis (cDAPSA; ρ = 0.867, p < 0.0001). Multivariable analysis showed that the PsAID-12 is determined by the articular disease activity (cDAPSA, p < 0.0001), severity of psoriasis (PsO; physician’s global assessment, p < 0.0001), and the presence of a coexisting fibromyalgia (FM; p < 0.0001). Reliability: Cronbach’s alpha coefficient was 0.93 for the total PsAID-12. Interpretability: Applying the cDAPSA categorization of disease activity states, the PsAID-12 cutoff values resulted in 1.4 between remission and low disease activity (LDA), 4.1 between LDA and moderate disease activity (MDA), and 6.7 between MDA and high disease activity.Conclusion. The PsAID-12 is an excellent PRO to evaluate the effect of PsA. It should be carefully handled in patients with coexisting FM.