Table 2.

GEE model results for repeat cross-sectional analysis of cannabis ever-use, current use, and regular use among cases of ever use among high school students taking part in COMPASS (Canada) at two time points (T1, T2) prior to and one (T3) following recreational cannabis legalization.

Repeat cross-sectional analysis	Model 1 Ever use vs never-use (ref) n = 102 685		Model 2 Current use vs ever- and never-use (ref) n = 102 685		Model 3 Regular use vs occasional use (ref) n = 32 340
	AOR (95% CI)	p	AOR (95% CI)	p	AOR (95% CI)	p
Time
T1 (2016–17)†	0.94 (0.89, 0.99)	0.0107	0.96 (0.91, 1.01)	0.1163	1.04 (0.97, 1.12)	0.2759
T2 (2017–18) (ref)‡
T3 (2018–19)	1.05 (1.01, 1.08)	0.0090	1.04 (1.00, 1.09)	0.0703	1.00 (0.93, 1.07)	0.9857
Gender
Female (ref)
Male	1.13 (1.08, 1.19)	<0.0001	1.41 (1.33, 1.49)	<0.0001	1.77 (1.66, 1.90)	<0.0001
Province
Alberta (ref)
British Columbia	0.95 (0.68, 1.33)	0.7539	0.87 (0.62, 1.20)	0.3895	0.93 (0.79, 1.11)	0.4331
Ontario	0.90 (0.72, 1.13)	0.3758	0.95 (0.76, 1.18)	0.6341	1.07 (0.93, 1.23)	0.3518
Québec	0.98 (0.73, 1.32)	0.9016	0.72 (0.55, 0.94)	0.0175	0.56 (0.46, 0.69)	<0.0001
Grade
9 (ref)
10	1.96 (1.86, 2.08)	<0.0001	1.81 (1.69, 1.95)	<0.0001	1.04 (0.94, 1.14)	0.4557
11	2.89 (2.71, 3.09)	<0.0001	2.30 (2.13, 2.50)	<0.0001	1.00 (0.90, 1.10)	0.9208
12	3.98 (3.69, 4.30)	<0.0001	2.84 (2.60, 3.10)	<0.0001	1.01 (0.92, 1.12)	0.7864

^†indicates school year of data collection. Samples comprise all students without missing variables participating in COMPASS in a given school year. ^‡ T2 was chosen as the reference year to facilitate comparison between students unexposed to the cannabis legalization process and those who were directly exposed. All models controlled for ethnicity, spending money and school-level clustering.