Table 5.

Ordinal logistic regression of combined cigarette and cannabis use at age 16 and Psychotic Experiences at age 18

	Low cigarette use, high cannabis use (n = 58)			High cigarette use, low cannabis use (n = 102)			High cigarette use, high cannabis use (n = 66)
	OR	95% CI	p	OR	95% CI	p	OR	95% CI	p
1	2.50	1.04, 6.02	0.041	2.80	1.46, 5.34	0.002	3.73	1.83, 7.60	<0.001
2	2.76	1.13, 6.75	0.026	2.57	1.34, 4.95	0.005	3.87	1.89, 7.95	<0.001
3	3.41	1.38, 8.46	0.008	2.33	1.17, 4.63	0.016	3.77	1.78, 7.97	0.001
4a	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.
4b	3.47	1.36, 8.85	0.009	2.37	1.16, 4.85	0.018	3.86	1.72, 8.67	0.001
4c	2.55	0.96, 6.78	0.060	1.88	0.91, 3.87	0.088	2.42	0.97, 6.06	0.059
5	2.60	0.95, 7.11	0.062	2.58	0.99, 6.74	0.052	3.05	1.08, 8.61	0.035

Basline: low cigarette, low cannabis (n = 1530).

Model 1: PE at 18 by categorical cannabis and tobacco use at age 16 (excluding those with PEs at age 12).

Model 2: as model 1 with additional adjustment for pre birth confounders (family history of depression, family history of schizophrenia, gender, urban dwelling, maternal education).

Model 3: as model 2 with additional adjustment for childhood confounders (borderline personality, IQ at age 8, depression at age 12, conduct disorder trajectory group membership, peer problems, bullied).

Model 4a: n.a.

Model 4b: as model 3 with additional adjustment for alcohol use.

Model 4c: as model 3 with additional adjustment for illicit drug use (other than cannabis).

Model 5: as model 3 with additional adjustment for alcohol and other illicit drug use.