Table 1 Univariate analysis for factors associated with intraoperative blood loss

Age

−0.02 (− 0.15–0.12)

0.82

Gender^b

0.30 (0.17–0.43)

< 0.01*

Body mass index

0.02 (− 0.12–0.16)

0.30

Smoking^b

−0.07 (− 0.21–0.06)

0.28

Preoperative hemoglobin level

0.18 (0.04–0.31)

0.01*

Preoperative Cobb angle

0.16 (0.02–0.29)

0.02*

Number of fused levels

0.46 (0.34–0.58)

< 0.01*

Operation duration

0.65 (0.54–0.75)

< 0.01*

Preoperative albumin level

0.12 (− 0.01–0.26)

0.07

Number of anchors

0.47 (0.35–0.59)

< 0.01*