Table 3.

Difference-in-difference tests of MMLs and dispensary provisions predicting past 30-day marijuana use among U.S. High School Students, 1991–2015 (N = 1,091,723).

	Any use Adjusted OR (95%CI)	Frequent use (≥20 times) Adjusted OR (95%CI)
Any MML [19 States (n = 304,952)]
All grades	0.94 (0.89–0.99)	0.95 (0.87–1.05)
9th grade	0.91 (0.83–0.99)	0.99 (0.83–1.18)
10th grade	0.95 (0.87–1.02)	0.99 (0.86–1.14)
11th grade	0.92 (0.84–1.01)	0.91 (0.79–1.06)
12th grade	0.96 (0.86–1.06)	0.90 (0.80–1.07)
Dispensaries Permitted [16 States (n = 259,049)]
All grades	0.97 (0.90–1.04)	0.96 (0.85–1.07)
9th grade	0.95 (0.86–1.06)	1.01 (0.83–1.23)
10th grade	1.01 (0.9101.11)	1.01 (0.85–1.20)
11th grade	0.94 (0.84–1.04)	0.95 (0.80–1.13)
12th grade	0.95 (0.84–1.08)	0.88 (0.74–1.04)
Dispensaries Active by 2015 [14 States (n = 192,835)]
All grades	0.93 (0.88–0.99)	0.98 (0.88–1.08)
9th grade	0.92 (0.83–1.01)	1.03 (0.85–1.24)
10th grade	0.93 (0.86–1.01)	1.00 (0.86–1.15)
11th grade	0.91 (0.82–1.01)	0.90 (0.77–1.06)
12th grade	0.95 (0.84–1.07)	0.98 (0.83–1.16)