Table 4.

Effect size of every 1 g increase in Hb, with and without factoring effect of perioperative blood transfusion based on general linear model

Without adjusting for perioperative transfusion*
Hb increase	Increase in LOS in days (95% CI)	p Value
1 g	−0.21 (-0.34 to 0.08)	0.002
2 g	−0.42 (-0.68 to 0.16)	0.002
3 g	−0.63 (-1.01 to 0.24)	0.002

After adjusting for perioperative transfusion†
Perioperative transfusion
0 units	REF
1 unit	4.02 (3.01 to 5.03)	<0.001
≥2 units	8.35 (6.97 to 9.73)	<0.001
Per unit increase in Hb by 1 g	−0.07 (-0.20 to 0.06)	0.28

*R²=0.114, adjusted R²=0.103.

†R² = 0.182, adjusted R²=0.171.

Hb, haemoglobin; LOS, length of stay; REF, reference.