The risk of irritable bowel syndrome among average frequency for medical visits of atopic dermatitis (AD) in Cox proportional hazard regression
| Average frequency for medical visit, per years | Event | Person-years | IR | Adjusted HR† (95% CI) |
| All | ||||
| None | 751 | 582 059 | 12.9 | 1.00(Reference) |
| ≤3 | 591 | 546 667 | 10.8 | 0.84 (0.75 to 0.94) |
| 4–5 | 129 | 20 477 | 63.0 | 4.63 (3.84 to 5.58)* |
| >5 | 374 | 16 285 | 229.7 | 16.7 (14.7 to 18.9)* |
| p for trend | <0.001 | |||
| Girl | ||||
| None | 308 | 264 049 | 11.7 | 1.00(Reference) |
| ≤3 | 287 | 248 989 | 11.5 | 0.99 (0.85 to 1.17) |
| 4–5 | 52 | 8868 | 58.6 | 4.75 (3.54 to 6.38)* |
| >5 | 155 | 6752 | 229.6 | 18.3 (15.0 to 22.2)* |
| p for trend | <0.001 | |||
| Boy | ||||
| None | 443 | 318 010 | 13.9 | 1.00(Reference) |
| ≤3 | 304 | 297 678 | 10.2 | 0.73 (0.64 to 0.85) |
| 4–5 | 77 | 11 608 | 66.3 | 4.51 (3.53 to 5.74)* |
| >5 | 219 | 9533 | 229.7 | 15.5 (13.2 to 18.3)* |
| p for trend | <0.001 | |||
*p<0.001
Adjusted HR†, adjusted for age and sex.
IR, incidence rate, per 10 000 person-years.