Table 1

Participant characteristics

Control messages
(n=359)
Chemical messages
(n=360)
n (%)n (%)
Age (years)
 21–29 81 (22.6)83 (23.1)
 30–39 86 (24.0)78 (21.7)
 40–49 59 (16.4)75 (20.8)
 50–59 90 (25.1)91 (25.3)
 60+43 (12.0)33 (9.2)
 Mean (SD)42.8 (13.6)42.1 (13.2)
Gender
 Male172 (47.9)196 (54.4)
 Female169 (47.1)151 (41.9)
 Transgender (includes other gender identity)18 (5.0)13 (3.6)
Gay, lesbian or bisexual88 (24.5)93 (25.8)
Hispanic56 (15.6)44 (12.2)
Race
 White136 (37.9)132 (36.7)
 Black or African American124 (34.5)133 (36.9)
 Asian29 (8.1)31 (8.6)
 American Indian or Alaska Native17 (4.7)17 (4.7)
 Native Hawaiian or other Pacific Islander11 (3.1)12 (3.3)
 Other/multiracial42 (11.7)35 (9.7)
Education
 High school graduate or less67 (18.7)89 (24.7)
 Some college151 (42.1)124 (34.4)
 College graduate114 (31.8)122 (33.9)
 Graduate degree27 (7.5)25 (6.9)
Household income, annual $
 0–24 999154 (42.9)170 (47.2)
 25 000–49 99988 (24.5)89 (24.7)
 50 000–74 99953 (14.8)35 (9.7)
75 000+64 (17.8)66 (18.3)
Low income, <200% of federal poverty level197 (54.9)216 (60.0)
Cigarettes smoked per day, mean (SD)9.97 (12.2)11.62 (16.9)
Smoking frequency
 Daily273 (76.0)281 (78.1)
 Non-daily86 (24.0)79 (21.9)
E-cigarette use in the past 3 weeks95 (26.5)94 (26.2)
Other tobacco product use in the past 3 weeks149 (41.5)139 (38.6)
Primary trial outcome at baseline
 Intended to quit smoking in the next month, mean (SD)2.36 (1.0)2.37 (0.9)
Secondary trial outcomes at baseline
 Made quit attempt (for 24 hours) in the past 3 weeks*96 (26.7)91 (25.3)
 Quit smoking for ≥7 days8 (2.2)6 (1.7)
 Number of times forgoing/butting out a cigarette in the past week, mean (SD)†4.9 (4.6)5.3 (4.8)
 Thinking about the harms of smoking, mean (SD)2.9 (1.1)2.8 (1.0)
 Thinking about quitting, mean (SD)2.8 (1.3)2.8 (1.2)
 Thinking about the chemicals in cigarettes, mean (SD)2.6 (1.3)2.5 (1.2)
  • Participant characteristics and outcomes did not differ by trial arm at baseline (all P>0.05). Baseline surveys did not assess awareness of health effects (on or not on labels), awareness of chemicals (on or not on labels), thinking about the message, negative affect, perceived likelihood of harm from smoking and number of conversations about the label. For thinking about the harms of smoking, baseline surveys included two of the three items (thinking about harms to self and harms to others) but not the third item on thinking about health problems caused by smoking.

  • *Quit attempts in the past three weeks were assessed at enrolment.

  • †Summed score, ranging from 0 to 20, reflecting number of times forgoing a cigarette and number of times butting out a cigarette.