Table 3

Studies of oral contraceptive usage in CD where isolated colonic disease was separately identified

Author/refStudy designN (total CD)n/% isolated colonic CD taking OC at onsetn/% all other CD taking OC at onsetOR/RR (95% CI) for OC use compared with healthy controls (when documented by disease location)OC use in isolated colonic vs all other CD
Rhodes et al50Case-control matched for age and year of onset379/12 75%11/25 44%NS increased p=0.09
Vessey et al88Cohort study in patients attending family planning clinics184/7 57%4/11 36%NS increased 0.63
Lashner et al89Case-control51 (including 8 isolated colonic)Isolated colonic
OR 0.50 (0.05–5.26)
Small bowel only
1.25 (0.34–4.64)
0.56 (0.20–1.52)
NS reduced
(and no significant association in this study between OC use and any CD)
Sandler et al90Case-control
Age-matched and excluding onset before menarche
184 (including 26 isolated colonic)Isolated colonic OR 2.63 (1.00–7.11)
Small bowel only 1.33 (0.70–2.53)
Ileocolonic 1.52 (0.82–2.83)
NS increased
Persson et al91Case-control age-matched and sex-matched152Isolated colonic
RR 3.6 (1.1–12.2)
Small bowel only
0.8 (0.3–2.4)
1.7 (0.8–4.0)
NS increased
Katschinski et al92Case-control premenopausal90
(including 30 isolated colonic)
Isolated colonic RR 3.2 (1.1–15.3)
Small bowel only RR 4.7 (1.6–17.8)
RR 3.8 (1.3–17.0)
NS reduced
Khalili et al93 Khalili and Chan94Cohort—nurses’ health315 (including 141 isolated colonic)Isolated colonic
HR 4.13 (1.77–9.68)
Ileal only
HR 2.99 (1.06–8.49)
NS increased
  • CD, Crohn's disease; NS, not significant; OC, oral contraceptive; RR, relative risk.