Table 3.

Type-I error of proposed tests under additive and multiplicative “null” models

Model	Type-I error rate	0.05	0.01	0.05	0.01	0.05	0.01	0.05	0.01
Multiplicative		0.054	0.012	0.058	0.012	0.050	0.013	0.046	0.008
		0.053	0.013	0.058	0.013	0.055	0.010	0.046	0.008
Additive		0.050	0.009	0.047	0.005	0.053	0.011	0.054	0.013
		0.051	0.008	0.042	0.007	0.049	0.011	0.055	0.011

The proposed method is evaluated using or with the corresponding risk regions being defined by the combinations of evenly placed grid points at various upper and lower quintiles of the risk distribution. Results are based on simulated datasets each involving a total of subjects with equal number of cases and controls. In each simulation, data are generated with models involving SNPs .