Background/Purpose: No validated definition of remission exists for psoriatic arthritis (PsA) to date. We previously identified 17.6% of our patients as having remission (no actively inflamed joints for 12 months). However, we did not take into account the other domains of the disease. We aimed to test the concept of remission as the absence of disease manifestations in PsA, determine the frequency of remission in our PsA cohort, and identify predictors for remission.

Methods: 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, which includes the information necessary for minimal disease activity (MDA) assessment. 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 to determine remission status for each patient and did a sensitivity analysis including only visits with all information available. We fit a Weibull regression model with interval/right censored and left truncated data adjusted for sex and disease duration at baseline. Both multivariable full model and reduced model with Hazard Ratio (HR), 95% confidence interval (CI) estimates, and p-value are provided in Table1.

Results: 985 patients (57% males, mean age 47.4 yrs Table) were included. Using imputation 175 (18.2%) patients had remission at least once and 107 (10.9%) achieved sustained remission. For the sensitivity analysis, using only patients who had complete data, 109 (10.9%) patients achieved remission at least once, and 48 (4.9%) sustained remission for 2 consecutive visits. Using baseline variables with imputation, only BMI was significant and lowered the chance of remission. In the sensitivity analysis no baseline variables were significant. Using a model with time varying covariates higher BMI lowered the chance of remission, while use of biologics increases the chance of remission. Similar results were obtained with the sensitivity analysis.

Conclusion: We defined remission as a state of no clinical activity. Remission occurred in 18% of patients with PsA at least once and was sustained in 11%. High BMI reduced and use of  biologic agents increased the chance of sustained remission.