Table 2

RR of colon cancer according to multivitamin supplement use in 1980 and family history of colorectal cancera,b

Multivitamin useNo family historyPositive family history
No. of casesPerson-yearsAge-adjusted RR (95% CI)Multivariate RR (95% CI)No. ofPerson-yearsAge-adjusted RR (95% CI)Multivariate RR(95% CI)
No298820,1891.01.08590,0412.30 (1.82–2.90)2.18 (1.71–2.78)
Yes130420,4850.84 (0.68–1.03)0.89 (0.72–1.10)2247,3201.13 (0.73–1.74)1.13 (0.73–1.75)
  • a Multivariate RRs are adjusted for age (5-year categories), pack-years of smoking before age 30 years (0, 1–5, 6–10, 11–15, or >15 pack-years), body-mass index (in quintiles), regular vigorous exercise (≥1 day/week), regular aspirin use (≥2 times per week), screening endoscopy (yes or no), beef, pork, or lamb as a main dish (<1 per month, 1–3 per month, 1 per week, 2–4 per week, or ≥5 per week), alcohol consumption (abstinence, history of greatly reduced consumption, or <15, 15–30, or >30 g/day), and energy-adjusted levels of methionine (≤1.4, 1.5–1.8, 1.9–2.2, >2.3 g/day).

  • b P for interaction for the cross-product term of multivitamin supplement use in 1980 and family history of colorectal cancer = 0.04.