Patient-reported Flares in Ankylosing Spondylitis: A Cross-sectional Analysis of 234 Patients.

OBJECTIVE

Ankylosing spondylitis (AS) is characterized by periodic flares. The objective of this study was to assess the frequency of patient-reported flares and their related factors.

METHODS

This cross-sectional study analyzed the 2004 data of a Canadian cohort. Participants had AS according to the modified New York criteria. Current flare status ("Are you experiencing a current flare"?), number of flares over the past 3 months, their average duration, the Bath Ankylosing Spondylitis Disease Activity and Functional Index (BASDAI and BASFI, respectively), and the AS Quality of Life questionnaire were assessed by self-report. Univariate and multivariate regressions analyzed the factors associated with current flare.

RESULTS

Among 234 analyzed patients, 169 (73.5%) were men, mean age was 45.5 (± 11.8) years, mean disease duration of 21.7 (± 11.7) years, and mean BASDAI and BASFI (0-10) of 4.4 (± 2.3) and 3.4 (± 2.6), respectively; 18 (7.7%) received antitumor necrosis factor (anti-TNF). Overall, 175 patients (74.8%) reported flares and 117 (50%) were currently in flare. Patients reporting flares had a median of 3 flares in 3 months, with a median duration of 2 weeks. Overall, the 234 patients spent a median of 25% of their time in flare. In multivariate analyses, current flare was significantly associated with higher BASDAI (OR 2.01, p = 0.01), worse quality of life (OR 1.37, p = 0.004), shorter AS duration (OR 1.19, p = 0.04), and less anti-TNF (OR 7.14, p = 0.03).

CONCLUSION

In this population, before the wide use of biologics, flares were frequent and long. As expected, flare was associated with higher disease activity, suggesting the validity of the concept of patient-reported flares.