Table 5.

Gateway Relations between (A) Cigarettes and Marijuana, (B) Alcohol and Marijuana, and (C) Alcohol and Cigarettes

Panel A: Cigarettes and Marijuana
Marijuana use at time 2
		Yes	No
Cigarettes at time 1	Yes	0.025	0.125	OR= 1.91
	No	0.061	0.581

Panel B: Alcohol and Marijuana
Marijuana use at time 2
		Yes	No
Alcohol at time 1	Yes	0.033	0.182	OR= 1.75
	No	0.054	0.524

Alcohol use at time 2
		Yes	No
Marijuana at time 1	Yes	0.014	0.058	OR= 0.58
	No	0.236	0.557

Panel C: Alcohol and Smoking
Smoking at time 2
		Yes	No
Alcohol at time 1	Yes	0.100	0.145	OR= 1.22
	No	0.229	0.421

Alcohol use at time 2
		Yes	No
Smokitig at time 1	Yes	0.034	0.176	OR= 0.41
	No	0.209	0.443

Increased risk: Among population at risk (those who were not marijuana users at time 1), the risk for using marijuana at time 2 was 1.91 times higher among those exposed to cigarettes at time 1 (.168) when compared to the unexposed population (.095).

Increased risk: Among population at risk (those who were not marijuana users at time 1), the risk for using marijuana at time 2 was 1.75 times higher among those exposed to alcohol (.152) at time 1 when compared to the unexposed population (.10).

Not increased risk: Among population at risk (those who were not alcohol users at time 1). the risk for using alcohol at time 2 was higher among non-marijuana users (.30) when compared with marijuana users at time I (.20).

Not increased risk: Among population at risk (those who were not cigarette users at time I), the risk for using cigarettes at time 2 was higher among alcohol users (.40) when compared with non-alcohol users at time 1 (.37).

Not increased risk; Among population at risk (those who were not alcohol users at time 1), the risk for using alcohol at time 2 was higher among non-smokers (.33) when compared with smokers at time 1 (.16).