TABLE 3.

Estimated probability of transitioning between stages of marijuana use and odds ratios by grade

	Estimated transition probability			Odds ratio (95 % CI)
				p value
	9th to 10th	10th to 11th	11th to 12th	10th to 11th vs. 9th to 10th	11th to 12th vs. 9th to 10th
No use to infrequent use	0.14	0.10	0.10	0.65 (0.41, 1.03) p = 0.068	0.65 (0.41, 1.02) p = 0.062
No use to frequent use and problems	0.03	0.05	0.01	1.35 (0.67, 2.74) p = 0.408	0.26 (0.08, 0.83) p = 0.023
Infrequent to frequent use and problems	0.24	0.15	0.07	0.72 (0.22, 2.36) p = 0.593	0.24 (0.06, 0.91) p = 0.036