Table 5.
Age at first OC use (yrs) | Never | 13-19 | 20-24 | 25-29 | 30-34 | 35+ | |
---|---|---|---|---|---|---|---|
| |||||||
N cases OR (95% CI)a | test for trend p | ||||||
|
|||||||
Colorectal adenoma | 2,981 | 190 | 836 | 877 | 588 | 618 | |
ref. | 0.99 (0.85, 1.15) | 1.02 (0.93, 1.12) | 1.06 (0.98, 1.16) | 1.05 (0.95, 1.15) | 1.08 (0.99, 1.18) | 0.04 | |
Subsites | |||||||
| |||||||
Proximal colon | 1,309 | 80 | 396 | 404 | 262 | 281 | |
ref. | 0.95 (0.75, 1.19) | 1.07 (0.93, 1.23) | 1.09 (0.96, 1.23) | 1.05 (0.91, 1.20) | 1.15 (1.00, 1.31) | 0.04 | |
Distal colon | 1,536 | 94 | 384 | 441 | 297 | 315 | |
ref. | 0.97 (0.78, 1.20) | 0.96 (0.84, 1.10) | 1.07 (0.96, 1.21) | 1.04 (0.92, 1.18) | 1.05 (0.93, 1.19) | 0.29 | |
Rectum | 556 | 35 | 133 | 145 | 108 | 107 | |
ref. | 0.98 (0.69, 1.39) | 0.89 (0.70, 1.12) | 0.96 (0.78, 1.18) | 1.05 (0.85, 1.29) | 1.00 (0.81, 1.23) | 0.90 | |
Stage | |||||||
| |||||||
Non-advanced | 1,210 | 88 | 415 | 420 | 277 | 245 | |
ref. | 1.07 (0.85, 1.33) | 1.06 (0.92, 1.22) | 1.13 (1.00, 1.27) | 1.16 (1.01, 1.32) | 1.10 (0.96, 1.27) | 0.01 | |
Advanced | 1,228 | 69 | 266 | 302 | 218 | 263 | |
ref. | 0.93 (0.73, 1.19) | 0.93 (0.79, 1.10) | 1.01 (0.88, 1.16) | 1.01 (0.87, 1.17) | 1.10 (0.96, 1.26) | 0.41 | |
Multiplicity | |||||||
| |||||||
1 | 1,945 | 123 | 623 | 620 | 399 | 380 | |
ref. | 0.93 (0.77, 1.12) | 1.02 (0.91, 1.14) | 1.06 (0.96, 1.17) | 1.05 (0.94, 1.18) | 1.06 (0.94, 1.18) | 0.17 | |
2+ | 788 | 52 | 189 | 216 | 150 | 163 | |
ref. | 1.09 (0.82, 1.45) | 1.01 (0.83, 1.23) | 1.07 (0.91, 1.27) | 1.03 (0.86, 1.24) | 1.07 (0.90, 1.27) | 0.34 |
Adjusted for age, BMI, height, physical activity, smoking, processed and red meat, folate intake, calcium, total energy intake, aspirin use, HT duration, family history, reason for endoscopy, time period of endoscopy, number of endoscopies, and years since most recent endoscopy.