Table 3.

Univariate associations between the occurrence of inflammatory bowel diseases and farm variables (odds ratios are given relative to the lowest category)

OR, Odds ratio; CI, confidence interval.

^*The survey provided information on 5604 individuals who could be confirmed to be ⩾15 years; any reduction in the total number of subjects included in each analysis was due to missing values in one or both variables.

^†95% CI calculated using Cornfield approximation since exact CIs could not be calculated with zero count cells.