Table 2 Baseline characteristics before and after PSM
Characteristics | Before PSM | After PSM | ||||||
|---|---|---|---|---|---|---|---|---|
Hypokalemia (390) | Normal (5793) | P value | SMD (%) | Hypokalemia (390) | Normal (390) | P value | SMD (%) | |
K+ | 3.2 ± 0.2 | 4.1 ± 0.4 | < 0.01* | — | 3.2 ± 0.2 | 4.1 ± 0.4 | < 0.01* | — |
Age (year) | 66.9 ± 12.0 | 63.0 ± 12.2 | < 0.01* | 30.4 | 66.9 ± 12.0 | 66.7 ± 10.7 | 0.756 | 2.2 |
Sex | < 0.01* | 32.7 | 0.217 | 8.8 | ||||
Male | 172 (44.1%) | 3426 (59.1%) | 172 (44.1%) | 155 (39.7%) | ||||
Female | 218 (55.9%) | 2367 (40.9%) | 218 (55.9%) | 235 (60.3%) | ||||
BMI (kg/m2) | 22.5 ± 3.3 | 22.6 ± 3.2 | 0.538 | 3.2 | 22.5 ± 3.3 | 22.6 ± 3.3 | 0.649 | 3.3 |
Smoking | 107 (27.4%) | 2184 (37.7%) | < 0.01* | 22.0 | 107 (27.4%) | 98 (25.1%) | 0.464 | 5.2 |
Drinking | 79 (20.3%) | 1797 (31.0%) | < 0.01* | 24.8 | 79 (20.3%) | 74 (19.0%) | 0.652 | 3.2 |
Hypertension | 167 (42.8%) | 1419 (24.5%) | < 0.01* | 39.5 | 167 (42.8%) | 157 (40.3%) | 0.467 | 5.2 |
T2DM | 67 (17.2%) | 612 (10.6%) | < 0.01* | 19.2 | 67 (17.2%) | 59 (15.1%) | 0.436 | 5.6 |
CHD | 30 (7.7%) | 256 (4.4%) | 0.003* | 13.7 | 30 (7.7%) | 25 (6.4%) | 0.484 | 5.0 |
Surgical history | 95 (24.4%) | 1404 (24.2%) | 0.956 | 0.3 | 95 (24.4%) | 102 (26.2%) | 0.564 | 4.1 |
Laparoscopy | 310 (79.5%) | 5052 (87.2%) | < 0.01* | 20.8 | 310 (79.5%) | 317 (81.3%) | 0.528 | 4.5 |
Tumor size | 0.047* | 10.3 | 0.943 | 0.5 | ||||
< 5 cm | 216 (55.4%) | 3503 (60.5%) | 216 (55.4%) | 215 (55.1%) | ||||
≥ 5 cm | 174 (44.6%) | 2290 (39.5%) | 174 (44.6%) | 175 (50.2%) | ||||
Tumor location | 0.001* | 17.0 | 0.613 | 3.6 | ||||
Colon | 219 (56.2%) | 2763 (47.7%) | 219 (56.2%) | 226 (57.9%) | ||||
Rectum | 171 (43.8%) | 3030 (52.3%) | 171 (43.8%) | 164 (42.1%) | ||||
Tumor stage | 0.197 | 8.3 | 0.583 | 2.2 | ||||
I | 62 (15.9%) | 1135 (19.6%) | 62 (15.9%) | 62 (15.9%) | ||||
II | 169 (43.3%) | 2429 (41.9%) | 169 (43.3%) | 163 (41.8%) | ||||
III | 159 (40.8%) | 2229 (38.5%) | 159 (40.8%) | 165 (42.3%) | ||||