Value of color Doppler ultrasound in preoperative typing diagnosis of acute appendicitis

Table 3 Multivariate Logistic regression analysis for preoperative prediction of suppurative appendicitis

Variable	β	SE	Wald χ2	P value	OR	95%CI
Max. diameter (≥ 9.8 mm)	1.230	0.229	28.84	< 0.001	3.42	2.18-5.37
Wall thickness (≥ 3.2 mm)	1.061	0.228	21.68	< 0.001	2.89	1.85-4.52
Blood flow (≥ grade II)	0.971	0.217	20.03	< 0.001	2.64	1.72-4.05
Constant	-3.156	0.315	100.32	< 0.001	0.043	-

Forward stepwise method (forward: LR) used for variable selection. Entry criterion P < 0.05, removal criterion P > 0.10. Hosmer-Lemeshow goodness-of-fit test: χ² = 6.82, P = 0.556; overall model prediction accuracy = 89.3%.