Table 2

 Characteristics of colorectal cases and controls

CharacteristicCases (n = 100)Controls (n = 600)Crude OR (95% CI)
*Compared with patients with body mass index ⩾20 and <26; body mass index missing for 207 patients.
NSAIDs, non-steroidal anti-inflammatory drugs; GI, gastrointestinal; IBD, inflammatory bowel disease; GPRD, General Practice Research Database; GP, general practitioner; OR (95% CI), odds ratio (95% confidence interval).
Mean age (y)62.962.7
Female sex42 (42.0%)252 (42.0%)
Body mass index*
    <206221.76 (0.66–4.71)
    ⩾26211670.78 (0.44–1.39)
Drug use 6 months before
    NSAIDs9660.80 (0.38–1.66)
    Aspirin9371.52 (0.70–3.28)
    Oral glucocorticoids331241.83 (1.17–2.88)
    Immunosuppressants3210.85 (0.25–2.94)
Medical history
    Colon/rectum polyps9610.24 (3.42–30.69)
    Colonoscopy 6–24 months before13751.05 (0.55–2.01)
    Prior GI hospitalisation 6–24 months before13481.69 (0.89–3.20)
    No of GP visits for IBD symptoms 6–24 months before
        1241381.24 (0.74–2.06)
        2+ or more18492.70 (1.45–5.04)
    Mean duration of follow up (y) prior to index date in GPRD4.54.3