Table 1.
Characteristics of the three study populationsa
| Adenoma Study | Colon Cancer Study | Rectal Cancer Study | |||||||
|---|---|---|---|---|---|---|---|---|---|
|
| |||||||||
| Cases (N=485) | Controls (N=578) | p-value | Cases (N=1424) | Controls (N=1780) | p-value | Cases (N=583) | Controls (N=775) | p-value | |
| Age | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | |||
| 58 (9.6) | 52.9 (11.0) | <0.01 | 65.2 (9.7) | 65.1 (10.3) | NAb | 62.3 (10.8) | 62.6 (10.5) | NAb | |
| Location | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |||
| Proximal | 104 (22) | NA | NA | 688 (50) | NA | NA | NA | NA | NA |
| Distal | 300 (62) | NA | 700 (50) | NA | NA | NA | |||
| Rectal | 77 (16) | NA | NA | NA | 583 | NA | |||
| Sex | |||||||||
| Male | 304 (63) | 227 (39) | <0.01 | 797 (56) | 946 (53) | NAb | 346 (59) | 428 (55) | NAb |
| Female | 181 (37) | 351 (61) | 627 (44) | 834 (47) | 237 (41) | 347 (45) | |||
| Study Center | |||||||||
| Kaiser Northern California | NA | NA | NA | 617 (43) | 647 (36) | <0.01 | 349 (60) | 449 (58) | 0.48 |
| Minnesota | 485 (100) | 578 (100) | 565 (40) | 791 (44) | NA | NA | |||
| Utah | NA | NA | 242(17) | 342 (19) | 234 (40) | 326 (40) | |||
| Regular use of aspirin or NSAIDs | |||||||||
| Yes | 180 (37.1) | 257 (44.5) | 0.02 | 562 (39.5) | 865 (48.6) | <0.01 | 263 (45.1) | 417 (53.8) | <0.01 |
| No | 305 (62.9) | 321 (55.6) | 862 (60.5) | 915 (51.4) | 320 (54.9) | 358 (46.2) | |||
| Body mass index | |||||||||
| Normal/Underweight | 159 (33.5) | 225 (39.8) | 0.10 | 475 (33.5) | 708 (39.8) | <0.01 | 184 (31.7) | 258 (33.5) | 0.31 |
| Overweight (25-29.9) | 204 (43.0) | 213 (37.7) | 578 (40.7) | 726 (40.9) | 242 (41.7) | 325 (42.2) | |||
| Obese (30+) | 111 (23.4) | 127 (22.5) | 366 (25.8) | 343 (19.3) | 155 (26.7) | 187 (24.3) | |||
a
Percentages may not total to 100% due to rounding and missing values.
b
NA – these were matching factors.