Table 3.
Incidence and adjusted hazard ratio of inflammatory bowel disease based on follow-up period for patients with appendectomy compared with controls.
| Appendectomy | Compared to control | |||||||
|---|---|---|---|---|---|---|---|---|
| Yes | No | |||||||
| Variables | Events | PY | Rate# | Events | PY | Rate# | Crude HR (95% CI) | Adjusted HR† (95% CI) |
| All | ||||||||
| Follow-up time, years | ||||||||
| <3 | 131 | 678,513 | 19.3 | 31 | 685,753 | 4.52 | 4.26 (2.88, 6.31)*** | 3.99 (2.69, 5.91)*** |
| 3–6 | 64 | 504,262 | 12.7 | 22 | 512,187 | 4.30 | 2.96 (1.82, 4.80)*** | 2.67 (1.64, 4.35)*** |
| >6 | 60 | 555,167 | 10.8 | 34 | 568,921 | 5.98 | 1.81 (1.19, 2.75)** | 1.74 (1.14, 2.66)* |
| Ulcerative colitis (UC) | ||||||||
| Follow-up time, years | ||||||||
| <3 | 54 | 7.96 | 15 | 2.19 | 3.63 (2.05, 6.44)*** | 3.30 (1.85, 5.88)*** | ||
| 3–6 | 32 | 6.35 | 11 | 2.15 | 2.96 (1.49, 5.86)** | 2.67 (1.34, 5.34)** | ||
| >6 | 30 | 5.40 | 23 | 4.04 | 1.34 (0.78, 2.30) | 1.28 (0.74, 2.22) | ||
| Crohn's disease (CD) | ||||||||
| Follow-up time, years | ||||||||
| <3 | 77 | 11.4 | 16 | 2.33 | 4.85 (2.83, 8.32)*** | 4.58 (2.67, 7.87)*** | ||
| 3–6 | 32 | 6.35 | 11 | 2.15 | 2.95 (1.49, 5.86)** | 2.65 (1.33, 5.29)** | ||
| >6 | 30 | 5.40 | 11 | 1.93 | 2.80 (1.40, 5.58)** | 2.69 (1.34, 5.40)** | ||
Rate#, Incidence rate per 10,000 person-years; Crude HR, relative hazard ratio;
Adjusted HR†, adjusted hazard ratio after control for age, sex, and comorbidities of CAD, hypertension, diabetes, hyperlipidemia, CVA, heart failure, COPD, CKD, alcohol-related diseases, cirrhosis, and biliary stone.
CAD, coronary artery disease; CI, confidence interval; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; CVA, cerebrovascular disease; PY, person years; SD, standard deviation.
*
P < 0.05,
**
P < 0.01,
***
P < 0.001.