Table 1

Appendicectomy rates in ulcerative colitis patients and matched controls

Subject characteristicsCases (n=307)Controls (n=1016)Crude OR95% CIp ValueMultivariate analysis OR95% CI
Mean (SEM) age (y)32.7 (0.85)33.6 (0.38) 0.32
Sex
    Female48.9%45.8% 0.34
    Male51.1%54.2%
Smoking
    Never smoker54.4%52.6%1.00(referent)1.00(referent)
    Current smoker 3.3%32.1%0.100.05–0.190.100.05–0.19
    Ex-smoker42.3%15.3%2.712.03–3.64<0.00013.292.38–4.56
(n=307)(n=896)
Appendicectomy
    No93.2%76.9%1.00(referent)1.00(referent)
    Yes 6.8%23.1%0.230.15–0.39<0.00010.230.14–0.38
(n=307)(n=892)
Age at appendicectomy
    None93.2%77.1%1.00(referent)1.00(referent)
    ≤20 y 3.3%15.3%0.170.09–0.340.160.08–0.32
    >20 y 3.5% 7.6%0.390.20–0.75<0.00010.410.20–0.83