Table 1 Preoperative characteristics and risk factors of patients.
| Variable | Analysis per protocol (n = 186) | Intention‐to‐treat analysis (n = 201) | ||||
|---|---|---|---|---|---|---|
| Study (n = 87) no (%) | Control (n = 99) no (%) | p Value | Study (n = 95) no (%) | Control (n = 106) no (%) | p Value | |
| Mean (SD) age (years) | 62.8 (10.1) | 65.4 (8.3) | 0.063 | 62.9 (10.2) | 65.6 (8.3) | 0.056 |
| Female | 14 (16.1) | 17 (17.2) | 0.844 | 17 (17.9) | 19 (17.9) | 0.996 |
| Inclusion criteria | ||||||
| Diabetes mellitus | 48 (55.2) | 50 (50.5) | 0.525 | 52 (54.7) | 55 (51.9) | 0.686 |
| Obesity (BMI >30) | 48 (55.2) | 49 (49.5) | 0.439 | 51 (53.7) | 51 (48.1) | 0.430 |
| BITA graft | 19 (21.8) | 22 (22.2) | 0.950 | 19 (20.0) | 23 (21.7) | 0.768 |
| Number of criteria | ||||||
| 1 factor | 62 (71.3) | 77 (77.8) | 0.308 | 69 (72.6) | 83 (78.3) | 0.350 |
| 2 factors | 22 (25.3) | 22 (22.2) | 0.624 | 23 (24.2) | 23 (21.7) | 0.672 |
| 3 factors | 3 (3.4) | 0 (0) | 0.201* | 3 (3.2) | 0 (0) | 0.207* |
| Other risk factors | ||||||
| Current smoker | 36 (41.4) | 49 (49.5) | 0.268 | 36 (37.9) | 49 (46.2) | 0.233 |
| COPD | 6 (6.9) | 6 (6.0) | 0.817 | 7 (7.4) | 7 (6.6) | 0.809 |
| Peripheral vascular disease | 5 (5.7) | 5 (5.1) | 0.834 | 5 (5.3) | 5 (4.7) | 0.859 |
| Mean (SD) duration of operation | 218.1 (53.7) | 214.2 (51.3) | 0.601 | 218.1 (54.1) | 214.2 (51.3) | 0.059 |
| Preoperative stay (days) (mean, median, (range)) | 2.6, 1 (1–61) | 2.5, 1 (0–35) | 0.776 | 2.6, 1 (1–62) | 2.5, 1 (0–35) | 0.851 |
| Re‐sternotomy for bleed | 1 (1.1) | 1 (1.0) | 1.000* | 1 (1.1) | 1 (0.9) | 1.000* |
| Postoperative ITU stay (days) (mean, median, (range)) | 2.1, 1 (1–20) | 2.4, 1 (1–17) | 0.498 | 2.0, 1 (1–20) | 2.3, 1 (1–17) | 0.557 |
| Preoperative serum creatinine level | ||||||
| >120 | 7 (8.0) | 10 (10.1) | 0.627 | 7 (7.4) | 10 (9.4) | 0.599 |
| >150 | 2 (2.3) | 2 (2) | 1.000* | 2 (2.1) | 2 (1.9) | 1.000* |
| NNIS risk prediction | ||||||
| 3.50% | 81 (93.1) | 92 (92.9) | 0.963 | 89 (93.7) | 98 (92.5) | 0.732 |
| 5.50% | 6 (6.9) | 7 (7.1) | 0.963 | 6 (6.3) | 8 (7.5) | 0.732 |
| SWIRS | 19.8% | 18.3% | 19.5% | 18.1% | ||
BITA, bilateral internal thoracic arteries; BMI, body mass index; COPD, chronic obstructive pulmonary disease; ITU, intensive therapy unit; NNIS, National Nosocomial Infections Surveillance System; SWIRS, sternal wound infection risk score.
*χ2 test with Yates correction.