Table 2 Baseline characteristics of participants
Characteristics | Control group (n = 7162) | Experimental group (n = 7585) |
|---|---|---|
Age, mean (SD), y | 60 (13) | 62 (12) |
Gender, n (%) | ||
 Male | 3354 (48.5) | 3472 (45.9) |
 Female | 3559 (51.5) | 4099 (54.1) |
Types of surgeries, n (%) | ||
 Thoracic | 2316 (32.3) | 2193 (28.9) |
 Hepatobiliary-pancreatic | 638 (8.9) | 690 (9.1) |
 Gastrointestinal | 1595 (22.3) | 1921 (25.3) |
 Urologic | 365 (5.1) | 500 (6.6) |
 Gynecologic | 1760 (24.6) | 2036 (26.8) |
 Other | 488 (6.8) | 245 (3.2) |