Table 1.
Characteristics of colorectal polyp cases and controls, Group Health, 1998–2007
| Characteristics at colonoscopy | Controls (N=754) | Advanced adenomasa (N=139) | Non-advanced adenomasb (N=518) | Non-adenomatous polypsc (N=380) |
|---|---|---|---|---|
| Age (years), N (%) | ||||
| <50 | 65 (9) | 5 (4) | 28 (5) | 19 (5) |
| 50–59 | 291 (39) | 53 (38) | 192 (37) | 177 (47) |
| 60–69 | 272 (36) | 51 (37) | 194 (37) | 133 (35) |
| 70–79 | 126 (17) | 30 (22) | 104 (20) | 51 (13) |
| Sex, N (%) | ||||
| Male | 306 (41) | 78 (56) | 277 (53) | 170 (45) |
| Female | 448 (59) | 61 (44) | 241 (47) | 210 (55) |
| Race, N (%) | ||||
| Caucasian | 656 (87) | 121 (87) | 439 (85) | 337 (89) |
| Black/African American | 20 (3) | 4 (3) | 11 (2) | 3 (1) |
| Asian/Pacific Islander | 33 (4) | 8 (6) | 27 (5) | 15 (4) |
| Other | 45 (6) | 6 (4) | 41 (8) | 25 (7) |
| Body mass index (kg/m2), N (%) | ||||
| <25 | 298 (40) | 45 (33) | 157 (31) | 160 (42) |
| 25–30 | 309 (41) | 56 (41) | 221 (43) | 142 (37) |
| ≥30 | 144 (19) | 37 (27) | 136 (26) | 78 (21) |
| Unknown | 3 | 1 | 4 | 0 |
| Previous endoscopy, N (%) d | ||||
| No | 340 (45) | 90 (65) | 281 (55) | 176 (47) |
| Yes | 408 (55) | 48 (35) | 232 (45) | 201 (53) |
| Unknown | 6 | 1 | 5 | 3 |
a
Adenoma cases have at least one tubular, tubulovillous, or villous adenoma ≥10 mm in diameter, with ≥20% villous components, or high-grade dysplasia.
b
Non-advanced adenoma cases have at least one tubular or tubulovillous adenoma, all <10 mm in diameter, with <20% villous components, and no high-grade dysplasia.
c
Non-adenomatous polyp cases had at least one hyperplastic polyp, traditional serrated adenoma, or sessile serrated adenoma, and no adenomas.
d
Colonoscopy or sigmoidoscopy performed ≥2 years before study colonoscopy.