Table 1

Age, sex, body mass index (BMI), and smoking in cases and controls by disease group

All IBDUCCDIndeterminate
CaseControlCaseControlCaseControlCaseControl
IBD, inflammatory bowel disease, UC, ulcerative colitis; CD, Crohn’s disease.
Total (n)16 55082 917830141 589596029 843228911 485
Incident (n)720541 535351820 415233613 96613517154
Female (%)53.653.748.948.958.758.857.257.3
Male (%)46.446.351.151.141.341.242.842.7
Age at entry (y)
    <40 (%)42.3442.1735.6235.4551.2851.1643.4743.14
    40–59 (%)32.232.135.435.328.228.230.830.5
    60–79 (%)19.820.022.823.015.715.919.820.0
    80 or over (%)3.94.04.14.33.33.44.34.6
    Mean46.1646.348.5948.7442.842.8946.0746.31
    SEM0.140.060.190.090.240.110.390.18
BMI (kg/m2)
    <19 (%)32225232
    19–24 (%)3327322635273327
    25–29 (%)1819212015171919
    30–34 (%)56664556
    >35 (%)22222212
    Unknown (%)3946384540473844
    Mean2525252624252525
    SEM0.040.020.060.030.080.040.120.06
Smoking
    Never (%)33332333
    Non-smoker (%)4237483735374137
    Ex-smoker (%)54744454
    Current (%)1921122028212221
    Unknown (%)3036313630362935