Table 2.

Baseline demographics, comorbidities and surgical data for reoperation group and non-reoperation groups

Variables	Non-reoperation	Reoperation
		Early reoperation	P	Late reoperation	P
Demographic data
Age (yr)	64.9 ± 11.1	68.1 ± 11.6	0.09	66.9 ± 9.5	0.28
Female n (%)	455 (60.6%)	21 (60%)	0.89	19 (52.7%)	0.35
Weight (kg)	68.7 ± 11.5	71.2 ± 11.3	0.22	73.9 ± 11.4	0.01
BMI (kg/m2)	25.9 ± 3.6	26.3 ± 3.6	0.43	27.1 ± 3.5	0.04
Comorbidities n (%)
Cardiovascular	401 (49.6%)	10 (29.4%)	0.14	12 (33.3%)	0.35
Diabetes	183 (24.4%)	15 (44.1%)	0.01	7 (19.4%)	0.50
Mental disease	14 (1.7%)	1 (2.9%)	0.65	0	0.41
Digestive disease	26 (34.6%)	3 (8.8%)	0.11	3 (8.3%)	0.13
Old cerebral infarction	21 (2.9%)	2 (5.9%)	0.29	1 (2.8%)	0.90
Pulmonary diseases	16 (2.1%)	2 (5.9%)	0.15	2 (5.5%)	0.18
Osteoporosis	29 (3.9%)	5 (14.7%)	0.01	3 (8.3%)	0.23
Surgical history	274 (36.5%)	17 (50.0%)	0.09	15 (41.6%)	0.53
Parkinson disease	9 (1.2%)	1 (2.9%)	0.38	1 (2.8%)	0.41
Nutrition status
Albumin (g/L)	39.5 ± 3.5	39.7 ± 4.2	0.58	40.0 ± 3.6	0.30
Prealbumin (g/L)	236.2 ± 54.0	243.4 ± 51.4	0.45	246.3 ± 55.0	0.63
Hemoglobin (g/L)	133.7 ± 15.5	133.5 ± 15.0	0.95	136.4 ± 14.5	0.24
Symptom duration (y)	6.8 ± 7.7	6.6 ± 6.7	0.99	7.7 ± 8.5	0.91
Primary diagnosis n (%)			0.79		0.94
DDD	184 (24.5%)	9 (26.4%)		7 (19.4%)
Lumbar stenosis	354 (47.1%)	14 (41.2%)		18 (50.0%)
Lumbar spondylolisthesis	213 (28.4%)	11 (32.4%)		11 (30.6%)
Surgical data
ASA	2.2 ± 0.5	2.2 ± 0.4	0.70	2.4 ± 0.5	0.12
Operative time (min)	216.2 ± 70.1	247.2 ± 93.8	0.01	243.2 ± 73.8	0.01
EBL (ml)	435.1 ± 343.1	501.6 ± 354.2	0.27	596.1 ± 362.9	0.01
Fusion level			0.06		0.01
1–2	569 (75.8%)	21 (61.8%)		17 (47.2%)
3–5	182 (24.2%)	13 (38.2%)		19 (52.8%)

Bold font indicates statistical significance

BMI, body mass index; DDD, degenerative disk disease; ASA, American Society of Anesthesiologists; and EBL, estimate blood loss