TY - JOUR T1 - Development and Validation of a New Instrument to Measure Health-related Quality of Life in Patients with Psoriatic Arthritis: The VITACORA-19 JF - The Journal of Rheumatology JO - J Rheumatol DO - 10.3899/jrheum.131021 SP - jrheum.131021 AU - Juan Carlos Torre-Alonso AU - Jordi Gratacós AU - José Santos Rey-Rey AU - Juan Pablo Valdazo de Diego AU - Ana Urriticoechea-Arana AU - Esteban Daudén AU - Mireia Moreno AU - Pedro Zarco-Montejo AU - Eduardo Collantes-Estévez AU - Juan Antonio Fernández-López Y1 - 2014/09/01 UR - http://www.jrheum.org/content/early/2014/08/26/jrheum.131021.abstract N2 - Objective To develop/validate an instrument to measure health-related quality of life (HRQoL) in patients with psoriatic arthritis (PsA), for use in clinical studies. Methods An item pool of 35 items was generated following standardized procedures. Item reduction was performed using clinimetric and psychometric approaches after administration to 66 patients with PsA. The resulting instrument, the VITACORA-19, consists of 19 items. Its validity content, internal consistency, test-retest reliability, known groups/convergent validity, and sensitivity to change were tested in a longitudinal and multicenter study conducted in 10 hospitals in Spain, with 323 patients who also completed the EuroQol 5-dimensional questionnaire (EQ-5D) and a health status transition item. There were 3 study groups: group A (n = 209, patients with PsA), group B (n = 71, patients with arthritis without psoriatic aspect, patients with arthrosis, and patients with dermatitis), and group C (n = 43, healthy controls). Results The questionnaire was considered easy/very easy to answer by 94.7% of the patients with PsA. The factorial analysis clearly identified only 1 factor. Cronbach’s alpha coefficient and interclass correlation coefficients exceeded 0.90. Statistically significant differences (p < 0.001) were observed between groups: subjects from group C had better HRQoL, followed by group B, and finally group A had the worst HRQoL. The VITACORA-19 scores showed significant correlations (p < 0.001) to PsA disease activity, EQ-5D, and perceived health state, scoring the patients with better health state higher. The minimum important difference was established as an 8-point change in the global score. Conclusion The Spanish-developed VITACORA-19, designed to measure HRQoL in patients with PsA, has good validity, reliability, and sensitivity to change. ER -