Table 3.

Simulation results.

β2	n	Purposeful	Stepwise	Backward	Forward
0.13	60	9.7	6.3	10.3	10.8
	120	25.8	19.8	24.9	23
	240	55.5	52	54.9	37.4
	360	66.4	65.5	65.8	38.7
	480	72.5	72.7	72.8	41.1
	600	71.4	72.9	72.9	42.9
0.07	60	7.5	3.1	4.4	6.7
	120	18.6	11.3	12.2	15.8
	240	32.2	22.5	22.9	21.4
	360	41.5	35.5	35.5	26.9
	480	47.9	44.5	44.5	34.6
	600	52	50.5	50.5	35.5

Retention of the correct model for purposeful, stepwise, backward, and forward selection methods, for two values of β₂ while specifying confounding at 15% and non-candidate inclusion at 0.15.