Table 4. Subsequent Colonoscopy Usage and Yield by Baseline Colonoscopy Findings in Participants Enrolled in the Study of Colonoscopy Utilizationa.
| Subsequent Procedure by Years of Follow-up | Advanced Adenoma (n = 1304) |
Nonadvanced Adenoma | No Adenoma (n = 1208) |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| All (n = 980) | ≥3 (n = 123) | 1-2 (n = 857) | ||||||||
| No. at Riskb | Cumulative, No. With Event (%)c | No. at Risk | Cumulative No. With Event (%)c | No. at Risk | Cumulative No. With Event (%)c | No. at Risk | Cumulative No. With Event (%)c | No.at Risk | Cumulative No. With Event (%)c | |
| Colonoscopyd | ||||||||||
| 3 | 834 | 443 (33.4) | 771 | 178 (20.5) | 92 | 29 (25.7) | 679 | 149 (19.8) | 1022 | 174 (11.4) |
| 5 | 452 | 842 (62.5) | 437 | 531 (53.9) | 50 | 73 (59.9) | 387 | 458 (53.0) | 661 | 531 (36.9) |
| 7 | 255 | 1011 (76.3) | 261 | 712 (72.2) | 29 | 94 (77.0) | 232 | 618 (71.5) | 399 | 768 (59.9) |
| 9 | 99 | 1070 (82.5) | 117 | 769 (78.7) | 12 | 102 (83.0) | 105 | 667 (78.1) | 146 | 843 (69.9) |
| Adenoma removal | ||||||||||
| 3 | 1116 | 188 (13.2) | 917 | 63 (6.1) | 109 | 14 (10.5) | 808 | 49 (5.5) | 1169 | 39 (2.7) |
| 5 | 954 | 350 (26.5) | 796 | 184 (18.2) | 84 | 39 (30.5) | 712 | 145 (16.4) | 1084 | 124 (8.8) |
| 7 | 720 | 442 (34.1) | 707 | 263 (26.6) | 70 | 53 (42.6) | 637 | 210 (24.3) | 925 | 185 (15.7) |
| 9 | 309 | 494 (40.4) | 344 | 318 (33.2) | 37 | 57 (47.4) | 307 | 261 (31.1) | 396 | 225 (20.3) |
| Advanced adenoma removal | ||||||||||
| 3 | 1254 | 50 (3.5) | 964 | 16 (1.5) | 120 | 3 (2.1) | 844 | 13 (1.4) | 1201 | 7 (0.4) |
| 5 | 1203 | 101 (7.7) | 939 | 41 (4.0) | 114 | 9 (6.9) | 825 | 32 (3.6) | 1181 | 27 (1.8) |
| 7 | 968 | 133 (10.4) | 911 | 56 (5.5) | 110 | 12 (9.1) | 801 | 44 (5.0) | 1058 | 43 (3.8) |
| 9 | 446 | 154 (13.0) | 475 | 73 (7.6) | 62 | 13 (10.7) | 413 | 60 (7.1) | 474 | 55 (4.8) |
a
Participants were considered at risk for colonoscopy until undergoing first subsequent colonoscopy. If there were no adenomas removed, the participant was still considered at risk for adenoma removal.
b
No. at risk indicates number at risk at the given time point.
c
Cumulative percentages were computed using weighted Kaplan-Meier analysis, in which weights were the inverse sampling weights from the study of colonoscopy utilization.
d
Median follow-up for subsequent colonoscopy was 9.0 y.