Objective: This study was designed to identify prognostic determinants of radiographical severity in patients with ankylosing spondylitis (AS) living in Daegu and Kyungpook territories.
Methods: One hundred-nineteen patients with AS were consecutively enrolled from four regional general hospitals. Clinical data including smoking habits, alcohol intake, disease duration, HLA-B27 positivity, involvement of peripheral joints, occupational activity, and regular exercise were investigated. Radiographical severity was assessed by the Modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Statistical analyses were performed using the independent Student's t-test, Pearson's correlation coefficient analysis, and multivariate regression analysis.
Results: Radiographical severity, as evaluated with the mSASSS, was associated with age of disease onset (p=0.011) and disease duration (p＜0.001). Additionally, mSASSS was significantly higher in males than females (p=0.039) and in patients without involvement of ankle arthritis than those with involvement of ankle arthritis (p=0.026). Patients with hip arthritis had significantly higher mSASSS scores than those without hip arthritis. A multivariate regression analysis showed that older age of disease onset, male gender, and disease duration were independent predictors of AS radiographical severity (p＜0.001, p=0.013, and p＜0.001, respectively). Hip arthritis was an independent predictor of C-spine radiographical severity in AS (p=0.031).
Conclusion: Radiographical severity of the prognosis was determined by age of disease onset, gender, and disease duration in patients with AS living in Daegu and Kyungpook territories.

Keywords: Ankylosing spondylitis, Age, Gender, Peripheral arthritis, mSASSS