Table 2.

Unadjusted and Adjusted Relative Risks of 100% Tobacco 21 Coverage on Smoking by Grade, Monitoring the Future, 2014–2019. Results Shown are using Imputed Data (m = 10).

	8th graders		10th graders		12th graders
	URR (95% CI)	ARR(95% CI)a	URR (95% CI)	ARR(95% CI)a	URR (95% CI)	ARR(95% CI)b
Smoking participation
100% T21 Coverage	0.46*** (0.35,0.59)	0.91 (0.69,1.20)	0.62* (0.40,0.95)	0.96 (0.75,1.23)	0.49*** (0.39,0.61)	0.74** (0.60,0.91)
N	92,922		88,628		81,082
First cigarette initiation
100% T21 Coverage	0.58*** (0.44,0.77)	0.87 (0.65,1.16)	0.67*** (0.54,0.83)	0.80 (0.61,1.04)	0.68* (0.50,0.93)	0.77 (0.54,1.09)
N	84,562		74,938		30,198
Daily smoking initiation
100% T21 Coverage	0.49* (0.28,0.86)	1.04 (0.58,1.85)	0.40*** (0.27,0.60)	0.70 (0.44,1.11)	0.42** (0.25,0.70)	0.65 (0.36,1.16)
N	91,457		85,468		37,571

^aRegression models estimating adjusted risk ratios controlled for gender, age, race/ethnicity, parents’ highest education, living arrangement, mother’s employment, high school program type, hours worked per week, weekly earnings from allowances or other sources, grade of smoking cigarette for first time, grade of starting daily smoking, having 5 or more drinks in a row over the past 2 weeks, marijuana use in the past 30 days, the year of survey administration, census region, cigarette taxes, workplace smoke-free policy coverage, restaurant and bar (hospitality) smoke-free policy coverage, percentage of individuals in state in poverty, percentage of individuals in state that are Black, percentage of individuals in state that are Hispanic or Latino.

^b12^th grade adjusted regression models controlled for all variables included in 8th and 10th grade models, as well as college plans.