Table 3.

Distribution of colonoscopy findings for derivation and validation cohort

Phase IPhase II
Patients who had colonoscopyPatients included in analysisPatients who had colonoscopyPatients included in analysis
n = 621n = 541n = 1,450n = 1,334
Pathologyn (%)n (%)n (%)n (%)
Center location
 Minnesota276 (44%)263 (49%)886 (61%)880 (66%)
 Louisiana168 (27%)110 (20%)367 (25%)258 (19%)
 Washington177 (29%)168 (31%)197 (14%)196 (15%)
Total number of polyps per colonoscopy
 0387 (62%)328 (61%)846 (58%)781 (59%)
 1110 (18%)91 (17%)321 (22%)290 (22%)
 >1124 (20%)122 (23%)283 (20%)263 (20%)
Total number of adenomas per colonoscopy
 0505 (81%)435 (80%)1,120 (77%)1,027 (77%)
 181 (13%)72 (13%)230 (16%)213 (16%)
 >135 (6%)34 (6%)100 (7%)94 (7%)
Total number of right-sided adenomas per colonoscopy
 0555 (89%)481 (89%)1,248 (86%)1,146 (86%)
 156 (9%)50 (9%)159 (11%)151 (11%)
 >110 (2%)10 (2%)43 (3%)37 (3%)
Total number of left-sided adenomas per colonoscopy
 0553 (89%)477 (88%)1,273 (88%)1,169 (88%)
 154 (9%)51 (9%)135 (9%)125 (9%)
 >114 (2%)13 (2%)42 (3%)40 (3%)
Total number of advanced adenomas per colonoscopy
 0587 (95%)508 (94%)1,370 (94%)1,258 (94%)
 130 (5%)29 (5%)63 (4%)60 (4%)
 >14 (0.6%)4 (0.7%)17 (1%)16 (1%)
Total number of hyperplastic polyps per colonoscopy
 0500 (81%)424 (78%)1,200 (83%)1,104 (83%)
 168 (11%)65 (12%)167 (12%)152 (11%)
 >153 (9%)51 (9%)83 (6%)78 (6%)