Table 1 The demographic and clinical characteristics of AS patients positive and negative for sydesmophyte
Clinical characteristic | AS N = 797 (%) | Sydesmophyte positive N = 393 (%) | Sydesmophyte negative N = 404 (%) |
|---|---|---|---|
Gender (female) | Â | Â | Â |
| Â | 130 (16.3%) | 26 (15.1%) | 104 (25.7%) |
Age at onset | Â | Â | Â |
   ≤16 | 117 (14.7%) | 55 (14.0%) | 62 (15.4%) |
   17 to 40 | 533 (66.9%) | 274 (69.7%) | 259 (64.1%) |
   41 to 60 | 47 (5.9%) | 12 (3.1%) | 35 (8.7%) |
   >60 | 1 (0.1%) | 0 (0%) | 1 (0.2%) |
   Undetermined | 99 (12.4%) | 52 (13.2%) | 47 (11.6%) |
Disease duration | Â | Â | Â |
   <5 years | 20 (2.5%) | 4 (1.0%) | 16 (4.0%) |
   5 to 10 years | 118 (14.8%) | 17 (4.3%) | 101 (25.0%) |
   11 to 15 years | 134 (16.8%) | 54 (13.8%) | 80 (19.8%) |
   16 to 20 years | 125(15.7%) | 52 (13.2%) | 73 (18.1%) |
   >20 years | 301 (37.8%) | 214 (54.5%) | 87 (21.5%) |
   Undetermined | 99 (12.4%) | 52 (13.2%) | 47 (11.6%) |
HLA-B27 positivity | Â | Â | Â |
| Â | 739 (92.7%) | 380 (96.7%) | 359 (88.9%) |
Baseline mSASSS at evaluati on | Â | Â | Â |
   mSASSS <3 | 404 (50.7%) |  |  |
   mSASSS <24 | 120 (15.0%) |  |  |
   mSASSS ≤24 | 273 (34.3%) |  |  |