Table 1.
The Observed Association of Smoking Behavior and IBD Subtypes Controlling for Age, Sex, and Socio-Economic Position
| Inflammatory Bowel Disease | Crohn’s Disease | Ulcerative Colitis | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Smoking | N | OR (95% CI) | P-value | N | OR (95% CI) | P-value | N | OR (95% CI) | P-value |
| Ever vs Never | 335,467 | 1.46 (1.37, 1.56) | <0.001 | 335,467 | 1.50 (1.34, 1.67) | <0.001 | 335,467 | 1.42 (1.31, 1.54) | <0.001 |
| Current vs Former | 151,645 | 0.78 (0.70, 0.88) | <0.001 | 151,645 | 1.24 (1.05, 1.47) | 0.01 | 151,645 | 0.57 (0.49, 0.66) | <0.001 |
| Cigarettes per day | 100,029 | 1.01 (1.00, 1.01) | 0.001 | 100,029 | 1.00 (0.99, 1.01) | 0.40 | 100,029 | 1.01 (1.00, 1.02) | 0.001 |
| Lifetime smokinga | 335,483 | 1.22 (1.17, 1.27) | <0.001 | 335,483 | 1.36 (1.27, 1.45) | <0.001 | 335,483 | 1.12 (1.06, 1.18) | <0.001 |
aA composite measure of smoking duration, intensity, and cessation. One unit increase in lifetime smoking is equivalent to having smoked 30 cigarettes a day for 17 years and stopping 13 years ago OR smoking 30 cigarettes a day for 19 years and stopping 15 years ago for example.