Analysis of risk factors for perioperative hidden blood loss in unilateral biportal endoscopic spine surgery: a retrospective multicenter study

Table 4 Results of multivariate linear regression analysis

Coefficients	Unstandardized	SE	Standardized	t	P
Coefficients	β	SE	β	t	P
Constant	−251.2	154.265		−2.105	0.384
Age	2.548	0.851	0.103	4.021	0.000**
Number of fusion levels	−46.325	15.541	−0.059	−2.054	0.015*
ASA classification	29.597	9.651	0.078	3.951	0.046*
Surgery time	−1.954	0.318	−0.031	−0.895	0.017*
PBV	62.254	19.682	0.108	3.65	0.026*
TBL	1.542	0.133	0.382	3.951	0.001**
Postoperative Hb	3.542	0.951	0.005	0.651	0.72
Postoperative Hct	−7.121	3.654	−0.082	−2.682	0.034*
Hb loss	1.654	1.955	0.016	0.984	0.534
Hct loss	42.652	15.698	0.216	3.934	0.005**
APTT	−2.398	1.498	−0.038	−1.739	0.351
Fibrinogen	−65.681	23.951	−0.235	−4.065	0.0278*

Note: *P < 0.05, **P < 0.01
ASA American Society of Anesthesiologists, Hct hematocrit, Hb hemoglobin, APTT activated partial thromboplastin time, TBL total blood loss, PBV patient’s blood volume

ISSN: 1749-799X