Multivariate ORs and 95% CIs for total iron (mg per day), dietary iron (mg per 1000 kcal), iron and haeme iron from meat (mg per 1000 kcal), iron from supplements (mg per day), and nitrate plus nitrite (mg per 1000 kcal) ...
Interactions by gender were not statistically significant (P>0.05) (data not shown). In addition, we evaluated all associations stratified by time between baseline and follow-up flexible sigmoidoscopy screening (3 or 5 years) and risk estimates were not substantially different (data not shown).