Table 2.

Univariate logistic regression analysis of risk factors.

Covariates	P-value	OR	95%CI		OR(95%CI) plot
			Lower	Upper
Intercept	0.336	0.503
Intraoperative blood loss	0.030*	1.002	1.000	1.004
Postoperative drainage volume	0.014*	1.003	1.001	1.006
Frequency of blood transfusion	0.021*
i 1	0.016*	0.227	0.068	0.757
≥2	0.300	0.505	0.139	1.838

95% CI, 95% confidence interval.

^*P <0.05.