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. Author manuscript; available in PMC: 2019 Feb 1.
Published in final edited form as: Health Educ Behav. 2017 Jul 17;45(1):32–42. doi: 10.1177/1090198117709884

Figure 3. Changes in knowledge of toxic constituent index over time.

Figure 3.

aMeans adjusted for age, sex, education, income, daily smoking, wave, and time-in-sample. Indices were standardized by averaging the responses to the number of toxic constituents qualitatively described on each country’s HWLs, that is, 2 for Australia and Canada, 3 for Mexico, and 1 for the United States. Numbers of observations were 2,292 in Australia, 2,554 in Canada, 2,246 in Mexico, and 2,474 in the United States, and the numbers of smokers were 1,036 in Australia, 1,190 in Canada, 1,166 in Mexico, and 1,229 in the United States. Data were collected once every four months from September 2012 (Wave 1) to January 2014 (Wave 5) in Australia, Canada, and Mexico. For Australia, only the four waves of data after policy implementation were used for analysis, since new HWLs were introduced 3 months after data collection started. Data collection started one wave later in the United States due to parent project aims, producing four waves of data. ***p < .001 for linear trend