Fig. 1.

Favorability ^a toward raising the minimum legal age of sale of tobacco products to 21 years among adults in the United States, 2014–2017.^b

^a“Favorability” is defined as a response of “strongly favor” or “somewhat favor”; opposition is defined as a response of “somewhat oppose” or “strongly oppose”

^bA statistically significant difference in overall Tobacco 21 favorability was observed across years (p < 0.001). Comparisons of favorability from baseline (2014) with subsequent years (2015, 2016, 2017) and interim years (2014–2015; 2015–2016; 2016–2017) was assessed by chi-square test (p < 0.05 considered statistically significant)

*Indicates a significant difference in favorability from baseline (2014). A significant difference was observed in in 2015 (p = 0.017) and 2016 (p = 0.003); a statistically significant comparison was not observed in 2017 (p = 0.876)

†Indicates a significant difference in favorability from previous reporting year. A significant difference was observed during 2014–2015 (p = 0.017), 2015–2016 (p < 0.001), and 2016–2017 (p = 0.004).