Table 4.

Multiple linear regression analysis of risk factors of HBL.

Parameters	Unstandardized		Standardized beta	t	P	95% CI
	B	SE
Operative time (min)	0.241	0.186	0.143	1.296	0.198	-0.128	0.609
PLTpost (109/L)	0.245	0.169	0.092	1.448	0.150	-0.090	0.581
The number of surgical fixation segments	36.577	12.246	0.474	2.987	0.004∗	12.299	60.856
The number of pedicle screws	10.938	6.415	0.243	1.705	0.091	-1.780	23.655
Type of scoliosis	8.579	6.843	0.081	1.254	0.213	-4.989	22.147
Correction angle (°)	-0.721	1.022	-0.047	-0.706	0.482	-2.747	1.304
TBV (mL)	0.018	0.017	0.067	1.061	0.291	-0.016	0.053

^∗ indicates a risk factor of HBL (P < 0.05). PLT_post: postoperative platelets.