Table 1. Patient and polyp characteristics.
| Original cohort | Propensity score matched cohort 1 | |||||||
| EMR | UEMR | d | P | EMR | UEMR | d | P | |
| No. of polyps | 179 | 171 | 121 | 121 | ||||
| Age (mean, SD) | 63.4 (9.9) | 65.4 (11.7) | .18 | .03 | 64.2 (10.0) | 64.1 (12.3) | .00 | .95 |
| Sex | .01 | .91 | .05 | .73 | ||||
| Male | 112 (62.6) | 108 (63.2) | 76 (62.8) | 79 (65.3) | ||||
| Female | 67 (37.4) | 63 (36.8) | 45 (37.2) | 42 (34.7) | ||||
| Colon preparation | –.23 | .03 | .00 | 1.00 | ||||
| Good-excellent | 163 (91.1) | 165 (96.5) | 115 (95) | 115 (95) | ||||
| Fair | 16 (8.9) | 6 (3.5) | 6 (5) | 6 (5) | ||||
| Polyp location | -.01 | .87 | –.08 | 1.00 | ||||
| Left colon | 79 (46.2) | 77 (43) | 51 (42.1) | 56 (46.3) | ||||
| Right colon | 100 (58.5) | 94 (52.5) | 70 (57.9) | 65 (53.7) | ||||
| Polyp size | .32 | < .01 | .04 | .70 | ||||
| Mean (SD) | 15.8 (6.0) | 18.0 (7.6) | 16.6 (6.5) | 17.0 (7.2) | ||||
| Group | .32 | < .01 | .06 | .97 | ||||
| 10 – 19 mm | 128 (71.5) | 98 (57.3) | 79 (65.3) | 78 (64.5) | ||||
| 20 – 24 mm | 35 (19.6) | 43 (25.1) | 28 (23.1) | 27 (22.3) | ||||
| 25 – 29 mm | 9 (5) | 17 (9.9) | 8 (6.6) | 10 (8.3) | ||||
| > 30 mm | 7 (3.9) | 13 (7.6) | 6 (5) | 6 (5) | ||||
| Polyp morphology | .23 | .21 | .14 | .75 | ||||
| Type 0-Is | 76 (42.5) | 54 (31.6) | 42 (34.7) | 49 (40.5) | ||||
| Type IIa (LST-G) | 31 (17.3) | 37 (21.6) | 22 (18.2) | 20 (16.5) | ||||
| Type IIa (LST-NG) | 50 (27.9) | 56 (32.7) | 41 (33.9) | 40 (33.1) | ||||
| SSA/P | 22 (12.3) | 24 (14) | 16 (13.2) | 12 (9.9) | ||||
| Prior manipulation | .15 | .15 | .07 | .58 | ||||
| None | 132 (73.7) | 114 (66.7) | 84 (69.4) | 80 (66.1) | ||||
| Yes | 47 (26.3) | 57 (33.3) | 37 (30.6) | 41 (33.9) | ||||
| Polyp pathology | .22 | .37 | .14 | .89 | ||||
| Adenoma without HGD | 84 (46.9) | 77 (45) | 57 (47.1) | 59 (48.8) | ||||
| HGD or CIS | 65 (36.3) | 63 (36.8) | 45 (37.2) | 45 (37.2) | ||||
| Adenocarcinoma (T1-shallow) | 1 (0.6) | 6 (3.5) | 1 (0.8) | 2 (1.7) | ||||
| Adenocarcinoma (T1-deep) | 4 (2.2) | 5 (2.9) | 2 (1.7) | 3 (2.5) | ||||
| SSA/P | 25 (14) | 20 (11.7) | 16 (13.2) | 12 (9.9) | ||||
| Water jet scope | .55 | < .01 | .00 | 1.00 | ||||
| No | 141 (78.8) | 92 (53.8) | 86 (71.1) | 86 (71.1) | ||||
| Yes | 38 (21.2) | 79 (46.2) | 35 (28.9) | 35 (28.9) | ||||
EMR, standard endoscopic mucosal resection; UEMR, underwater endoscopic mucosal resection; d, standardized difference; SD, standard deviation; LST-G: granular type lateral spreading tumor; LST-NG, non-granular type lateral spreading tumor; SSA/P, sessile serrated adenoma/polyp; HGD, high-grade dysplasia; CIS, carcinoma in situ
1
Variables in the propensity score included age, sex, colon preparation, polyp location, polyp size, polyp morphology, polyp pathology, usage of water jet, and prior endoscopic manipulation of the target polyp