Table 2.
Association between MML passage and adolescent marijuana use, adjusted for adolescent’s perceptions of the perceived harmfulness+ of marijuana (1992++–2014)
| Odds ratio (95% CI) | |
|---|---|
| Pre-post change, all grades | 0.95 (0.86 – 1.04) |
| Pre-post change, 8th grade | 0.81 (0.72 – 0.92)** |
| Pre-post change, 10th grade | 1.00 (0.89 – 1.12) |
| Pre-post change, 12th grade | 1.00 (0.89 – 1.12) |
| Living in a state that ever passes an MML versus never, all grades | 1.21 (1.06 – 1.39) ** |
| Living in a state that ever passes an MML versus never, 8th grade | 1.16 (0.99 – 1.35) † |
| Living in a state that ever passes an MML versus never, 10th grade | 1.20 (1.03 – 1.39) |
| Living in a state that ever passes an MML versus never, 12th grade | 1.26 (1.08 – 1.46)** |
| Perceives marijuana use to be harmful versus not, all grades | 0.11 (0.11 – 0.11) ** |
| Perceives marijuana use to be harmful versus not, 8th grade | 0.11 (0.11 – 0.12)** |
| Perceives marijuana use to be harmful versus not, 10th grade | 0.11 (0.11 – 0.11)** |
| Perceives marijuana use to be harmful versus not, 12th grade | 0.12 (0.11 – 0.12)** |
Notes: “Living in a state that ever passes an MML versus never” is not a pre-post test. It indicates the odds of marijuana use among adolescents in states that ever pass an MML at any point from 1992 through 2014 compared to those in states that never pass a law over the same time period. The “Pre-post change” is a pre-post test, it indicates the estimated change in adolescent marijuana use after an MML is passed.
Model controlled for gender, age, race, parent education, class size, urban/rural, public/private, state-aggregated % male, % white, % with no high school education, % population aged 11–24. The model also included a state random intercept, and state-specific cubic spline polynomials to control for trend with one knot at the year 2000.
Based on survey question: “How much do you think people risk harming themselves (physically or in other ways) if they smoke marijuana occasionally?” Response options were dichotomized into “Great risk” and “Moderate risk” versus “slight risk”, and “no risk”.
Effects were estimated from 1992–2014 as models including 1991 data did not converge
p<0.10;
p<0.05,
p<0.01