Table 2.
Adjusted odds ratios for overall colorectal cancer with corresponding 95% confidence intervals associated with various smoking exposures
| Variable | Colorectal Cases | Control Subjects | Adjusted Odds Ratio* | |||
|---|---|---|---|---|---|---|
| N | (%) | N | (%) | OR | 95% Confidence Interval | |
| Smoking Status | ||||||
| Never | 745 | (59.9%) | 2,055 | (55.5%) | 1.00 | Referent |
| Former Smoker | 156 | (12.6%) | 412 | (11.1%) | 1.22 | 0.94 – 1.56 |
| Current Smoker | 342 | (27.5%) | 1,234 | (33.3%) | 0.79 | 0.66 – 0.96 |
| Amount Smoked | ||||||
| Never Smoker | 745 | (59.9%) | 2,055 | (55.5%) | 1.00 | Referent |
| < 1 Pack/Day | 127 | (10.3%) | 396 | (10.8%) | 0.95 | 0.74 – 1.23 |
| 1 Pack/Day | 252 | (20.2%) | 853 | (23.0%) | 0.85 | 0.69 – 1.05 |
| > 1 Pack/Day | 119 | (9.6%) | 397 | (10.7%) | 0.87 | 0.67 – 1.15 |
| Years Smoked | ||||||
| Never Smoker | 745 | (59.7%) | 2,040 | (54.9%) | 1.00 | Referent |
| 1–27 Years | 165 | (13.2%) | 544 | (14.6%) | 0.89 | 0.71 – 1.11 |
| 28–41 Years | 169 | (13.6%) | 563 | (15.1%) | 0.84 | 0.66 – 1.06 |
| > 41 Years | 168 | (13.5%) | 570 | (15.3%) | 0.89 | 0.68 – 1.15 |
| Pack-Years | ||||||
| Never Smoker | 745 | (60.6%) | 2,040 | (55.7%) | 1.00 | Referent |
| 1–24 Pack-Years | 162 | (13.2%) | 527 | (14.4%) | 0.92 | 0.73 – 1.15 |
| 25–45 Pack-Years | 157 | (12.8%) | 557 | (15.2%) | 0.82 | 0.65 – 1.05 |
| > 45 Pack-Years | 165 | (13.4%) | 536 | (14.6%) | 0.92 | 0.72 – 1.19 |
| Lifetime Tar Grams♪ | ||||||
| Never Smoker | 355 | (69.9%) | 1,136 | (67.8%) | 1.00 | Referent |
| 1–3,133 Grams | 57 | (11.2%) | 174 | (10.4%) | 1.13 | 0.78 – 1.64 |
| 3,133–8,989 | 45 | (8.9%) | 186 | (11.1%) | 0.85 | 0.57 – 1.28 |
| > 8,989 | 51 | (10.0%) | 180 | (10.7%) | 1.04 | 0.69 – 1.56 |
*
Adjusted for race, age, gender, body mass index, county of residence, and other tobacco use.
♪
Lifetime Tar Grams = Brand Specific Tar Level * (Cigs/Day * 365) * Years