Table 1 Patient characteristics

Age (y)

68.79 ± 7.88

65.23 ± 8.48

0.015

Gender, male (%)

21 (44.7%)

49 (43.0%)

0.843

BMI (kg/m²)

24.43 ± 2.24

24.91 ± 2.24

0.210

 Hypertension, n (%)

22 (46.8%)

34 (29.8%)

0.040

 Diabetes, n (%)

12 (25.5%)

17 (14.9%)

0.111

 Cerebrovascular disease, n (%)

3 (6.4%)

5 (4.4%)

0.693

 Respiratory disease, n (%)

6 (12.8%)

16 (14.0%)

0.831

 Heart disease, n (%)

8 (17.0%)

11 (9.6%)

0.191

 Smoking, n (%)

15 (31.9%)

30 (26.3%)

0.472

 Albumin (g/L)

36.13 ± 2.54

38.32 ± 3.52

< 0.01

 Total-cholesterol (mmol/L)

4.41 ± 0.88

4.19 ± 0.99

0.191

 Creatinine (μmol/L)

130.45 ± 37.32

120.74 ± 35.10

0.119

 White blood cells (*10⁹/L)

6.48 ± 1.47

6.43 ± 1.52

0.841

 Lymphocyte (%)

27.67 ± 7.58

27.48 ± 8.61

0.897

 Hemoglobin (g/L)

114.36 ± 15.11

119.96 ± 16.30

0.045

 Platelet (*10⁹/L)

206.89 ± 57.25

203.82 ± 53.99

0.748

 Fusion levels

6.57 ± 1.91

6.18 ± 1.85

0.220

 Decompression levels

2.32 ± 1.04

2.07 ± 1.03

0.166

 Intra-operative blood loss (ml)

1021.28 ± 392.28

871.49 ± 340.61

0.016

 Blood transfusion, n (%)

14 (29.8%)

24 (21.1%)

0.235

 Operative time (min)

270.43 ± 37.06

260.18 ± 38.89

0.125

 Hospital stay (day)

15.60 ± 3.20

13.89 ± 2.71

0.001