Table 2.
Incidence risk of main outcome between propensity score matched ankylosing spondylitis and non-ankylosing spondylitis groups.
| Event | Non-AS N = 6754 |
AS N = 6754 |
p Value |
|---|---|---|---|
| Any outcome | |||
| Follow up person months | 696,943 | 666,896 | |
| New case | 408 | 709 | |
| Incidence rate † (95% CI) | 0.59 (0.53–0.65) | 1.06 (0.99–1.14) | |
| Crude Relative risk (95% CI) | Reference | 1.802 (1.595–2.035) | |
| AHR (95% CI) | Reference | 1.826 (1.616–2.063) | <0.0001 * |
| Dry eye | |||
| Follow up person months | 710,667 | 685,762 | |
| New case | 267 | 504 | |
| Incidence rate † (95% CI) | 0.38 (0.33–0.42) | 0.73 (0.67–0.80) | |
| Crude Relative risk (95% CI) | Reference | 1.947 (1.678–2.258) | |
| AHR (95% CI) | Reference | 1.973 (1.701–2.290) | <0.0001 * |
| Keratopathy | |||
| Follow up person months | 712,411 | 697,502 | |
| New case | 225 | 351 | |
| Incidence rate † (95% CI) | 0.32 (0.28–0.36) | 0.50 (0.45–0.56) | |
| Crude Relative risk (95% CI) | Reference | 1.586 (1.341–1.875) | |
| AHR (95% CI) | Reference | 1.593 (1.347–1.883) | <0.0001 * |
| Corneal ulcer | |||
| Follow up person months | 729,389 | 726,261 | |
| New case | 42 | 34 | |
| Incidence rate † (95% CI) | 0.06 (0.04–0.08) | 0.05 (0.03–0.07) | |
| Crude Relative risk (95% CI) | Reference | 0.813 (0.517–1.278) | |
| AHR (95% CI) | Reference | 0.805 (0.512–1.266) | 0.4598 |
AS: ankylosing spondylitis, N: number, DED: dry eye disease, AHR: adjusted hazard ratio, CI: confidence interval, * denotes significant difference between the two groups after adjusting age, sex, urbanization, education level and co-morbidities, † incidence rate: per 1000 person-month.