Table 1.
Demographic characteristics of the patients in the two periods
| Prior period (n = 131) | Latter period (n = 151) | P value | |
| Age (yr, mean ± SD) | 62.7 ± 10.4 | 63.0 ± 12.4 | 0.847 |
| Sex (male/female) | 68/63 | 91/60 | 0.158 |
| Diabetes mellitus (yes/no) | 17/114 | 20/131 | 0.947 |
| Smoking history (yes/no) | 24/107 | 32/119 | 0.547 |
| ASA classification (ASA score ≤ 2/3 ≤) | 124/7 | 146/5 | 0.399 |
| Body mass index (kg/m2) | 22.4 ± 3.3 | 22.5 ± 3.5 | 0.802 |
| Subcutaneous fat (mm, mean ± SD) | 18.2 ± 7.8 | 19.7 ± 7.1 | 0.081 |
| Site (colon/rectum) | 73/58 | 95/56 | 0.220 |
| Operation time (min, median) | 206 | 219 | 0.864 |
| Blood loss(mL, median) | 205 | 200 | 0.169 |
| Stoma (yes/no) | 32/99 | 31/120 | 0.433 |
| Patients with high risk1 | 40 | 75 | 0.001 |
| Patiens with PD | 0 | 151 |
1
High risk patients whose depth of subcutaneous tissue are over 20 mm. ASA: American Society of Anesthesiologists; PD: Penrose drains.