Table 2.
Incidence and adjusted hazard ratio of inflammatory bowel disease based on sex, age, and comorbidities 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 | 255 | 1,737,942 | 14.7 | 87 | 1,766,861 | 4.92 | 2.98 (2.33, 3.79)1*** | 2.78 (2.17, 3.55)*** |
| Ulcerative colitis (UC) | 116 | 6.67 | 49 | 2.77 | 2.40 (1.72, 3.36)*** | 2.23 (1.59, 3.12)*** | ||
| Crohn's disease (CD) | 139 | 8.00 | 38 | 2.15 | 3.71 (2.59, 5.31)*** | 3.48 (2.42, 4.99)*** | ||
| Gender | ||||||||
| Female | 119 | 851,339 | 14.0 | 38 | 863,289 | 4.40 | 3.17 (2.20, 4.57)*** | 2.95 (2.04, 4.26)*** |
| Male | 136 | 886,602 | 15.3 | 49 | 903,572 | 5.42 | 2.82 (2.04, 3.91)*** | 2.64 (1.90, 3.67)*** |
| Age, years | ||||||||
| ≤34 | 101 | 713,152 | 14.2 | 29 | 704,429 | 4.12 | 3.45 (2.28, 5.21)*** | 3.33 (2.20, 5.04)*** |
| 35–49 | 64 | 553,971 | 11.6 | 13 | 560,303 | 2.32 | 4.98 (2.74, 9.03)*** | 4.63 (2.54, 8.44)*** |
| >50 | 90 | 470,819 | 19.1 | 45 | 502,128 | 8.96 | 2.13 (1.49, 3.04)*** | 1.81 (1.26, 2.60)** |
| Comorbidity | ||||||||
| No | 175 | 146,6719 | 11.9 | 63 | 1,628,953 | 3.87 | 3.09 (2.32, 4.12)*** | 3.12 (2.34, 4.17)*** |
| Yes | 80 | 271,222 | 29.5 | 24 | 137,908 | 17.4 | 1.69 (1.07, 2.67)* | 1.75 (1.11, 2.77)* |
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.