Preoperative baseline variables
|
Age at surgery, mean (SD)
|
56.9 (13.4)
|
56.7 (16.0)
|
56.9 (13.3)
|
0.010
|
BMI, mean (SD)
|
24.1 (3.1)
|
23.9 (3.9)
|
24.1 (3.1)
|
0.750
|
Male
|
237 (43)
|
12 (63.2)
|
225 (42.1)
|
0.900
|
Diabetes
|
60 (10.8)
|
2 (10.5)
|
58 (10.8)
|
0.300
|
Smoker
|
144 (26.0)
|
6 (31.6)
|
138 (25.8)
|
0.235
|
Chronic steroid use
|
11 (1.99)
|
5 (26.3)
|
6 (1.1)
|
0.003
|
Albumin level < 3.5 g/dl
|
13 (2.35)
|
3 (15.8)
|
10 (1.9)
|
0.001
|
Diagnose
|
Herniation
|
270 (48.7)
|
6 (31.6)
|
264 (49.3)
|
-
|
Stenosis
|
86 (15.5)
|
6 (31.6)
|
80 (15.0)
|
0.180
|
Spondylolisthesis
|
198 (35.7)
|
7 (36.8)
|
191 (35.7)
|
0.001
|
Operative variables
|
Operative time, mean (SD), min
|
160.8 (43.9)
|
155.5 (48.2)
|
161.0 (43.8)
|
0.178
|
Bleeding volume, mean (SD) mL
|
318.5 (90.8)
|
321.1 (105.7)
|
311.9 (89.2)
|
0.537
|
Postoperative variables
|
Albumin level < 3.5 g/dl
|
314 (56.7)
|
16 (84.2)
|
298 (55.7)
|
< 0.001
|
Albumin level < 3.0 g/dl
|
110 (19.9)
|
10 (52.6)
|
100 (18.7)
|
< 0.001
|
Postoperative drainage median, ml, (IQR)
|
223.5 (151.0–309.0)
|
148 (93.0-188.0)
|
231 (154.0–312.0)
|
0.116
|
Length of stay, day, median, thousand CNY (SD)
|
11.0 (9.0–14.0)
|
22.0 (14.0–32.0)
|
11.0 (9.0–14.0)
|
< 0.001
|
Hospitalization expenses mean (SD)
|
25.6 (8.7)
|
43.9 (21.3)
|
24.9 (7.2)
|
< 0.001
|