Patient demographics
| Cases (n = 68) | Controls (n = 136) | Total (n = 204) | |
|---|---|---|---|
| Sex (%) | |||
| Males | 39 (57) | 78 (57) | 117 (57) |
| Females | 29 (43) | 58 (43) | 87 (43) |
| Age at onset of UC (y) (median (range)) | 33 (6–62) | 33 (8–65) | 33 (6–65) |
| Duration of UC (y) (median (range)) | 21 (5–52) | 23 (7–55) | 22 (5–55) |
| Total No of colonoscopies | 407 | 810 | 1217 |
| No of colonoscopies per patient (median (range)) | 5 (1–17) | 5 (1–13) | 5 (1–17) |
| Year index colonoscopy (median (range)) | 1990 (1973–2001) | 1989 (1972–2001) | 1989 (1972–2001) |