Predictors of common bile duct lithiasis in laparoscopic era

Table 7 Building the model via forward stepwise regression.

	Summary of stepwise regression; variable: lithiasis. Forward stepwise P to enter: 0.05, P to remove: 0.05
	Steps	Degrees of freedom	F to remove	P to remove	F to enter	P to enter	Effect status
History	Step 1	1			0.18442	0.6688	Out
CBD_10		1			15.9619	0.0001	Out
SGOT		1			48.4107	1.05E-09	Out
Bil		1			63.4082	1.3E-11	Entered
ALP		1			55.3074	1.31E-10	Out
Bil	Step 2	1	63.4082	1.29624E-11			In
CBD_10		1			10.6347	0.0016	Entered
SGOT		1			9.16433	0.0033	Out
History		1			3.33518	0.0717	Out
ALP		1			7.98087	0.0060	Out
Bil	Step 3	1	54.81658	1.61316E-10			In
CBD_10		1	10.6347	0.0016709			In
SGOT		1			8.23132	0.0053	Entered
History		1			0.31224	0.5779	Out
ALP		1			6.52043	0.0127	Out
Bil	Step 4	1	17.77605	6.94475E-05			In
CBD_10		1	9.667935	0.0026617			In
SGOT		1	8.231323	0.0053630			In
History		1			0.39927	0.5294	Out
ALP		1			4.50211	0.0372	Entered
Bil	Step 5	1	5.631729	0.0202726			In
CBD_10		1	8.529480	0.0046459			In
SGOT		1	6.148871	0.0154574			In
ALP		1	4.502116	0.0372471			In
History		1			0.62724	0.4309	Out