Table 1.
Descriptive and Quantitative Data for Screening Studies
| Number of Patients with Proximal Neoplasia/Total Number for Each Group (%) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| First Author, Year of Study | Mean Age, Y (Range) | Study Design | Definition of Distal Colon | Size of Distal Polyp Studied | Distal Polyp Required for Colonoscopy | Total Number | Distal Hyperplastic Polyps | Distal Adenomas | No Distal Polyps | Miscellaneous Polyps |
| Achkar, 199015 | 56 (27 to 87) | Retrospective | Reach of 35- cm sigmoidoscope | 9 mm or smaller | Yes | 172 | 21/72 (29) | 23/69 (33) | 4/31 (13) | |
| Blue, 199149 | 59 (31 to 91) | Retrospective | Reach of 35- cm sigmoidoscope | — | Yes | 185 | 19/69 (26) | 29/99 (29) | 1/17 (6) | |
| Brady, 199334 | 62 (50 to 81) | Prospective | Reach of 60-cm sigmoidoscope | ≤5 mm | No | 162 | 6/42 (14) | 31/78 (40) | 5/42 (12) | |
| Deal, 199148 | — (43 to 80) | Retrospective | Distal 60 cm of colon | — | Yes | 211 | 26/75 (35) | 42/115 (37) | ||
| Foutch, 199143 | 64 (≥50) | Prospective | Reach of 60-cm sigmoidoscope | — | No | 129 | 8/25 (32) | 13/31 (42) | 11/73 (15) | |
| Lieberman, 19914 | 64 (50 to 76) | Prospective | Reach of 60-cm sigmoidoscope | — | No | 105 | 6/21 (29) | 8/19 (42) | 18/65 (28) | |
| Nusko, 199647 | 59 (42 to 83) | Retrospective | Rectosigmoid | — | Yes | 304 | 10/65 (15) | 86/239 (36) | ||
| Opelka, 199250 | 62 | Prospective | Reach of 60-cm sigmoidoscope | ≤5 mm | Yes | 76 | 9/30 (30) | 16/40 (40) | 1/6 (17) | |
| Rex, 199245 | — | Prospective | Rectosigmoid | — | No | 480 | 8/45 (18) | 22/58 (38) | 58/377 (15) | |
| Stoltenberg, 199146 | 62 (52 to 72) | Prospective | Reach of 35-cm sigmoidoscope | ≤5 mm | Yes | 100 | 12/56 (21) | 11/41 (27) | ||