Table 1. Baseline characteristics of the study participants by selected demographic and established colorectal cancer risk factors.
| Variable | Cases | Sub-cohort members | IRR1 (95% CI) | ||
|---|---|---|---|---|---|
| N (%) | Median (5–95%) | N (%) | Median (5–95%) | ||
| Total | 920 (35) | 1743 (65) | |||
| Sex | |||||
| Men | 516 (56) | 935 (54) | |||
| Women | 404 (44) | 808 (46) | |||
| Age at inclusion (years) | 58 (50–64) | 56 (50–64) | |||
| BMI (kg/m2) | 26.3 (20.6–34.3) | 25.6 (20.5–35.9) | 1.05 (1.01–1.10)5 | ||
| Food intake (g/day) | |||||
| Alcohol2 | 15.1 (1.2–71.4) | 14.2 (1.2–65.7) | 1.04 (1.00–1.08)6 | ||
| Dietary fiber | 19.8 (10.5–32.7) | 20.6 (10.7–34.2) | 0.88 (0.78–1.01)7 | ||
| Red and processed meat | 112.3 (47.1–233.4) | 109.4 (42.5–236.3) | 1.03 (0.99–1.07)8 | ||
| Vitamin D from diet (μg/day) | 4.4 (1.9–8.8) | 4.5 (1.9–9.0) | 1.01 (0.87–1.18)9 | ||
| Vitamin D from supplements (μg/day)3 | 4.2 (0.5–11.4) | 4.2 (0.4–10.0) | - | ||
| Total vitamin D (μg/day) | 5.8 (2.3–12.7) | 6.0 (2.2–14.0) | 0.94 (0.86–1.02)10 | ||
| Smoking status | |||||
| Never | 277 (30) | 574 (33) | 1.00 (ref.) | ||
| Past | 280 (30) | 519 (30) | 1.05 (0.84–1.30) | ||
| Current | 363 (40) | 650 (37) | 1.13 (0.92–1.39) | ||
| NSAID use4 | |||||
| No | 641 (70) | 1204 (69) | 1.00 (ref.) | ||
| Yes | 279 (30) | 539 (31) | 1.00 (0.83–1.20) | ||
| HRT use among women | |||||
| Never | 244 (60) | 423 (52) | 1.00 (ref.) | ||
| Past | 52 (13) | 127 (16) | 0.64 (0.44–0.93) | ||
| Current | 108 (27) | 258 (32) | 0.71 (0.53–0.95) | ||
values are expressed as medians (5th and 95th percentiles) or as fractions (%). IRR, incidence rate ratio; CI, confidence interval; BMI, body mass index; NSAID, non-steroidal anti-inflammatory drug; HRT, hormone replacement therapy
1 IRRs for colorectal cancer estimated by the Cox proportional hazards model mutually adjusted for all variables, with age as the underlying time axis, and stratified by gender, so that the baseline hazards are gender specific. 95% CI are based on Wald’s tests.
2 Among current drinkers (Ncases = 897; Nsub-cohort = 1702).
3 Among supplement users (Ncases = 392; Nsub-cohort = 817).
4 NSAID use is defined as ≥2 pills per month for one year.
5 Risk estimate per 2 kg/m2 increment of BMI.
6 Risk estimate for the increment of 10 g alcohol per day.
7 Risk estimate for the increment of 10 g dietary fibres per day.
8 Risk estimate for the increment of 25 g red and processed meat per day.
9 Risk estimate for the increment of 3 μg vitamin D from the diet per day.
10 Risk estimate for the increment of 3 μg vitamin D from diet and supplements per day.