Table 4.
Numbers, proportions and odds ratios (95% CI) for composite features in the three years before diagnosis of AS/index date
| Comparison with population controls | Comparison with symptomatic controls | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Cases (N = 74) | Controls (N = 296) | Controls (N = 169) | ||||||||
| Composite features | N | % | N | % | OR | (95% CI) | N | % | OR | (95% CI) |
| Axial pain within 30 days of NSAID | 29 | 39.2 | 20 | 6.8 | 10.4 | (4.9, 22.1) | 45 | 26.6 | 1.8 | (0.9, 3.6) |
| Axial pain within 360 days of large joint symptom | 9 | 12.2 | 8 | 2.7 | 7.2 | (2.2, 24.0) | 11 | 6.5 | 1.5 | (0.5, 4.2) |
| Axial pain separated by 180 days | 17 | 23.0 | 7 | 2.4 | 12.7 | (4.7, 34.6) | 17 | 10.1 | 2.8 | (1.3, 5.9) |
| Axial pain separated by 360 days | 10 | 13.5 | 5 | 1.7 | 8.0 | (2.7, 23.4) | 11 | 6.5 | 2.2 | (0.8, 5.6) |
| Axial pain, without ever sciatica | 36 | 48.7 | 27 | 9.1 | 8.9 | (4.7, 16.9) | 82 | 48.5 | 1.1 | (0.6, 1.9) |
| Tendon disorders separated by 180 days | 1 | 1.4 | 1 | 0.3 | – | – | 0 | 0.0 | – | – |
| Tendon disorder within 360 days of axial pain | 6 | 8.1 | 2 | 0.7 | 21.7 | (2.6, 181.5) | 5 | 3.0 | 2.7 | (0.8, 9.0) |
| FBC within 90 days of axial pain | 7 | 9.5 | 4 | 1.4 | 8.6 | (2.2, 33.6) | 10 | 5.9 | 2.2 | (0.7, 7.3) |
| ESR within 180 days of axial pain | 4 | 5.4 | 0 | 0.0 | – | – | 1 | 0.6 | – | – |
| Iritis within 360 days of axial pain | 5 | 6.8 | 0 | 0.0 | – | – | 0 | 0.0 | – | – |
Feature names follow the format X relationship Y where relationship is defined as follows X within N days of Y – any occurrence of X within N days of any occurrence of Y (in either order)
X separated by > N days – two consecutive occurrences of X separated by more than N days
X without ever Y – one or more occurrences of X and no occurrences of Y