Table 3.

Correlation analysis between various factors and perioperative occult blood loss.

Factor	r	P	95% CI
Type of surgery	0.379	<0.001	0.2298-0.5101
Type of anesthesia	0.229	0.006	0.0680-0.3774
Postoperative drainage	0.245	0.003	0.0852-0.3922
Autologous blood transfusion	0.242	0.003	0.0817-0.3892