Table 2

Stratification of the study sample according to whether the index subjects had appendicitis at the time of appendicectomy

Appendicitis diagnosisCohortnFollow up before/after index date (person years)No of admission before/after index dateAdjusted ratio of UC admission rate (95% CI)
An adjusted ratio of ulcerative colitis (UC) admission rate below 1.0 suggests a beneficial effect of appendicectomy on the clinical course of UC.
95% CI, 95% confidence interval.
PresentIndex137646/823108/841.24 (0.71–2.19)
AbsentIndex65307/39963/330.76 (0.33–1.76)
AllIndex202953/1221171/1171.05 (0.67–1.67)