To determine the frequency of remission defined by the absence of the various disease manifestations of psoriatic arthritis (PsA) and identify predictors for remission.
Patients followed at the PsA clinic between 2000 and 2015 were included. Patients are assessed at 6- to 12-month intervals according to a standard protocol. Remission was defined as a visit that patients had no tender or swollen joints, no inflammatory back pain, no tender entheseal sites, minimal skin involvement with BSA<1%, patient pain on visual analog scale (VAS) score of <15, patient global disease activity VAS score of <20, Health Assessment Questionnaire (HAQ) score <0.5. We used imputation approach to determine remission status for visits with incomplete criteria for each patient.
Data from 985 patients (57% males, average age of 47.4 years) were included in this study. From 2000 to 2015, 175 (18%) patients achieved remission at least once and 92 (9%) experienced sustained remission over at least 2 consecutive visits. In a multivariate Weibull regression analysis for the time to remission, higher BMI was associated with lower chance of remission (HR = 0.96, p = 0.012), while the use of biologics increased the chance of achieving remission (HR = 1.48, p = 0.034). The effect of biologics was also significant on the chance of achieving sustained remission for 2 or more consecutive visits (HR = 1.76, p = 0.020). However, biologics were not significantly associated with sustained remission when it was defined based on 3 or more consecutive visits.
Remission occurred at least once in 18% of the patients with PsA while sustained remission occurred in 9% of the study sample. Having higher BMI would reduce the achievement of remission. The use of biologic agents increased not only the chance of remission, but also the chance of sustained remission for at least 12 months.