Characteristics associated with patient-reported treatment success in psoriatic arthritis

To determine characteristics associated with patient-reported treatment success in psoriatic arthritis (PsA).

Rheumatologist-diagnosed PsA patients fulfilling the CASPAR classification were recruited from a single center. PsA outcome measures included: 66/68 swollen/tender joint counts, Leeds/SPARCC dactylitis/enthesitis indices, psoriasis body surface area (BSA), and patient-reported outcomes (PROs) including PROMIS. The primary outcome was a patient-reported item: 'Today, considering the level of control of your psoriatic arthritis and psoriasis, do you consider your treatment has been successful?'. Descriptive and multivariate logistic regression analyses identified clinical predictors of patient-reported treatment success. Patient-reported reasons for lack of treatment success were explored.

A total of 178 participants had a baseline visit. Mean (SD) CASPAR score was 3.7 (0.9), age 51.7 (13.5) years, and BMI 31.3 (7.2) kg/m2. Fifty-two percent were women, and 86.0% white. Treatment success was reported by 116/178 (65%) patients in the analytic cohort. Among 76 patients who reported treatment failure, the most frequently selected reasons for lack of success were pain (n = 55, 72.4%), fatigue (n = 46, 60.5%), inflamed joints (n = 40, 52.6%) and stiffness (n = 40, 52.6%). Overall, 105 participants had complete data across variables in the logistic regression models. Patient-reported treatment success was independently associated with the 66-swollen/68-tender joint counts, psoriasis BSA, PROs (pain interference, physical function, fatigue) and TNF-inhibitor therapy, after controlling for BMI and demographics.

Patient-reported treatment success in PsA may be achieved through improvement of inflammatory arthritis, psoriasis, pain, physical function, fatigue and the use of TNF-inhibitors. Patients reported treatment failure was most commonly due to symptoms of pain, fatigue and stiffness.