Evaluating remission and low disease activity from the perspective of the patient with axial spondyloarthritis: The cross-sectional ConREspAx study.

Objectives: To evaluate the properties of a single question to determine patient perception of remission and disease activity; to compare this with existing definitions for remission and low disease activity (LDA).

Methods: Single-center, cross-sectional study in a tertiary care hospital. Patients with axSpA (fulfilling ASAS criteria) were consecutively included. Both the patient's perception of remission and LDA and that of the physician were evaluated with a single question. Agreement between the patients' perception and other current definitions was tested using the prevalence-adjusted and bias-adjusted kappa (PABAK). The sensitivity (S) and specificity (Sp) of current definitions of disease states were tested against the patient's perception as the gold standard.

Results: The study population included 105 axSpA patients (63.8% males; 67.6% with radiographic sacroiliitis). Patients considered themselves to be in remission in 21% of cases and in LDA in 51.4%; physicians considered patients to be in remission in 45.7% of cases and in LDA in 35.2%. The poorest agreement was recorded for the patient's and the physician's perception of remission. The best agreement for patients' perception of remission was for a BASDAI < 2 and normal C-reactive protein values. This definition was also the most sensitive (S=72.7%) and specific (Sp=83.1%) when the patient's perception was taken as the gold standard.

Conclusion: In a real-life setting, the evaluation of remission by the patient through a single question was the hardest criterion to achieve, although it did prove to be a feasible, valid, and specific way to assess remission.