Table 1 Patient characteristics
Total | Group A: low PBR, low NBR | Group B: low PBR, high NBR | Group C: high PBR, low NBR | Group D: high PBR, high NBR | p | |
|---|---|---|---|---|---|---|
Number of patients | 131,394 | 44,758 | 21,705 | 22,837 | 42,094 | |
Age (average ± SD, years) | 67.8 ± 11.5 | 69.0 ± 11.0 | 68.4 ± 11.2 | 66.5 ± 11.8 | 66.8 ± 11.7 | <0.001 |
Sex (males,%) | 62.8 | 62.4 | 62.1 | 62.9 | 63.5 | 0.001 |
Preoperative comorbidities (%) | ||||||
Hypertension | 17.5 | 16.2 | 15.9 | 19.2 | 18.7 | <0.001 |
Diabetes mellitus | 13.6 | 13.1 | 12.6 | 14.4 | 14.3 | <0.001 |
Cardiovascular diseases | 94.0 | 94.3 | 94.7 | 94.0 | 93.1 | <0.001 |
Chronic lung diseases | 4.9 | 4.1 | 3.9 | 5.2 | 6.1 | <0.001 |
Liver cirrhosis | 1.6 | 1.2 | 1.3 | 2.0 | 1.8 | <0.001 |
Chronic renal failure | 0.70 | 0.71 | 0.58 | 0.80 | 0.71 | 0.055 |
Cerebrovascular diseases | 0.48 | 0.55 | 0.43 | 0.43 | 0.47 | 0.061 |
Charlson Comorbidity Index (%) | ||||||
0-2 | 61.2 | 64.3 | 63.4 | 59.2 | 57.8 | <0.001 |
3-5 | 26.6 | 24.2 | 24.6 | 27.9 | 29.5 | |
6- | 12.2 | 11.5 | 12.0 | 12.9 | 12.7 | |
Hospital volume | ||||||
Low | 33.6% | 58.2% | 37.0% | 16.3% | 15.1% | <0.001 |
Medium | 33.0% | 27.0% | 37.4% | 35.1% | 36.0% | |
High | 33.4% | 14.8% | 25.6% | 48.6% | 49.0% |