Table 3.

Pooled multivariate relative risk (RR) and 95% confidence interval (CI) of cumulative alcohol intake and colorectal cancer according to folic acid fortification period among non-users of multivitamins and folic acid supplements

Alcohol (g/d)	0	0.1–4.9	5.0–9.9	10–14.9	15–29.9	30+	P for trend
All (1980/1986–2008)
No. of cases	314	549	198	171	170	140
Multivariate RR*	1.00	1.12 (0.97–1.29)	1.04 (0.86–1.25)	1.24 (1.02–1.50)	1.06 (0.87–1.29)	1.36 (1.09–1.70)	0.02
Pre-fortification era (1980/1986–1998)
No. of cases	215	324	123	114	101	96
Multivariate RR*	1.00	1.07 (0.83–1.37)	1.03 (0.82–1.30)	1.26 (0.99–1.60)	1.01 (0.78–1.29)	1.31 (1.00–1.71)	0.10
Post-fortification era (1998–2008)
No. of cases	169	134	66	51	43	28
Multivariate RR*	1.00	1.04 (0.82–1.32)	1.21 (0.87–1.68)	1.13 (0.56–2.30)	1.11 (0.72–1.70)	1.07 (0.69–1.65)	0.67

^*Multivariate RRs are adjusted for age, gender (combined data only), total pack-years of smoking (<10, 10-<30, 30-<50, 50-<70, 70+), physical activity (quintiles of metabolic equivalent tasks/wk), body mass index (BMI) (<23, 23-<25, 25-<30, 30-<35, and 35+ kg/m²), height (continuous), family history of colorectal cancer in parents and siblings (yes, no), history of endoscopy (yes, no), aspirin use (never, past, current use of 1–2, ≥3 tablets/wk), postmenopausal hormone (PMH) use (only in women; premenopausal, never, past, and current), red meat intake (quintiles), calcium intake from foods (continuous), and total energy intake (continuous)

^**P for heterogeneity by fortification period was 0.44.