Routine Assessment of Patient Index Data 3 Score and Psoriasis Quality of Life Assess Complementary Yet Different Aspects of Patient-Reported Outcomes in Psoriasis and Psoriatic Arthritis

Background: Psoriasis Quality of Life (PQoL-12) is a validated composite tool assessing patients' quality of life (QoL) with psoriasis (PsO) and psoriatic arthritis (PsA). Routine Assessment of Patient Index Data 3 (RAPID3), measuring physical function, pain, and patient global assessment, is used for rheumatoid arthritis. Routine Assessment of Patient Index Data 3 has not been used to assess PsO/PsA patients' QoL. Objective: The aim of this study was to investigate the correlation between PQoL-12 and RAPID3 in PsO and PsA patients in a cross-sectional and longitudinal analyses. Methods: Data came from PsO and PsA patients seen from 2008 to 2015 at Oregon Health & Science University (n = 558: 393 with PsO and 165 with PsA). Nonlinear least squares regressions modeled PQoL-12 with functions of RAPID3, controlling for time since first visit. Nonparametric ROC determined RAPID3 scores best correlating with PQoL-12 cutoffs. Results: Among the PsO cohort, PQoL-12 was explained by RAPID3, the square of RAPID3, time since first visit, and the square of time since first visit; adjusted R-2 = 0.414. For the PsA cohort, PQoL-12 was explained by RAPID3, change in slope of RAPID3 at 2.28, time since first visit, the square of time since first visit; adjusted R-2 = 0.340. Routine Assessment of Patient Index Data 3 cutoffs for PQoL-12 scores of 48 and 96 (mild and moderate QoL impairment) in PsO were 1.55 and 5.72 and in PsA were 1.89 and 6.34. Conclusions: Routine Assessment of Patient Index Data 3 weakly conelated with PQoL-12, indicating these indices assess different aspects of PsO and PsA. Routine Assessment of Patient Index Data 3 fails to capture mental health information that greatly impacts patients' QoL, whereas PQoL-12 fails to capture the physical and functional aspects of the disease. Results indicate the importance of capturing mental health assessment in order to create a comprehensive tool to measure how psoriatic disease affects patients' QoL.