Table 2 Comparison of overall patient baseline characteristics for the pre- vs postintervention phases, with P values
Baseline parameters | Preintervention | Postintervention | P value |
|---|---|---|---|
N = 10 151 | 5489 | 4662 |  |
Age (median [IQR]) | 69.60 [60.87 to 76.84] | 69.46 [60.37 to 76.83] | 0.55 |
Sex = female (%) | 2461 (44.8) | 2147 (46.1) | 0.23 |
ASA score (%) | Â | Â | 0.02 |
 1 or 2 | 2493 (45.4) | 2042 (43.8) |  |
 3–5 | 2987 (54.4) | 2601 (55.8) |  |
 Missing information | 9 (0.2) | 19 (0.4) |  |
BMI kg/m2 (median, IQR) | 26.9 (24.1, 30.5) | 26.7 (23.7, 30.0) | 0.001 |
Wound contamination class (%) |  |  |  < 0.001 |
 I (clean) | 4112 (74.9) | 3272 (70.2) |  |
 II (clean-contaminated) | 1166 (21.2) | 1203 (25.8) |  |
 III (contaminated) | 211 (3.8) | 187 (4.0) |  |
Procedure |  |  |  < 0.001 |
 Colon surgery | 1344 (24.5) | 1358 (29.1) |  |
 Cardiac surgery | 1682 (30.6) | 1245 (26.7) |  |
 Knee/hip implantation | 2463 (44.9) | 2059 (44.2) |  |
Elective surgery = yes (%) | 4696 (85.6) | 3873 (83.1) | 0.001 |
Antibiotic administration in relation to incision (median [IQR]) |  − 43 [− 55 to − 31] |  − 35 [− 49 to − 23] |  < 0.001 |
Exceeding T scorea = yes (%) | 1468 (26.7) | 1154 (24.8) | 0.02 |
Year (median [IQR]) | 2015 [2014 to 2016] | 2018.00 [2017 to 2018] |  < 0.001 |
Hospital (%) |  |  |  < 0.001 |
 1 | 794 (14.5) | 841 (18.0) |  |
 2 | 158 (2.9) | 127 (2.7) |  |
 3 | 873 (15.9) | 846 (18.1) |  |
 4 | 586 (10.7) | 679 (14.6) |  |
 5 | 1740 (31.7) | 773 (16.6) |  |
 6 | 31 (0.6) | 60 (1.3) |  |
 7 | 493 (9.0) | 578 (12.4) |  |
 8 | 814 (14.8) | 758 (16.3) |  |