Participant characteristics, n=810
| Characteristic | N | % |
| Demographic Characteristics | ||
| Age | ||
| 18–29 years | 159 | 20% |
| 30–39 years | 251 | 31% |
| 40–54 years | 204 | 25% |
| 55+ years | 187 | 23% |
| Mean (SD) | 41.9 | (14.6) |
| Gender identity | ||
| Man | 365 | 45% |
| Woman | 430 | 53% |
| Neither man nor woman or prefer to self-describe | 13 | 2% |
| Transgender | 40 | 5% |
| Gay, lesbian or bisexual | 94 | 12% |
| Hispanic ethnicity | 81 | 10% |
| Race | ||
| White | 620 | 77% |
| Black or African American | 97 | 12% |
| Asian or Pacific Islander | 34 | 4% |
| American Indian or Alaskan Native | 15 | 2% |
| Other race or multiracial | 44 | 5% |
| Education | ||
| High school diploma or less | 220 | 27% |
| Some college | 201 | 25% |
| Bachelor’s or associate’s degree | 274 | 34% |
| Graduate degree | 114 | 14% |
| Household income, annual | ||
| US $0–24 999 | 200 | 25% |
| US $25 000–49 999 | 195 | 24% |
| US $50,000–74 999 | 148 | 18% |
| US $75 000–99 999 | 85 | 10% |
| US $100 000+ | 182 | 22% |
| Low income (<150% of FPL) | 236 | 29% |
| Political party identification | ||
| Democrat | 357 | 44% |
| Republican | 277 | 34% |
| Independent or other | 176 | 22% |
| Behaviours and Health Status | ||
| Cigarette smoking frequency | ||
| Not at all | 58 | 7% |
| Some days | 174 | 21% |
| Every day | 578 | 71% |
| Vaping frequency | ||
| Not at all | 351 | 43% |
| Some days | 276 | 34% |
| Every day | 183 | 23% |
| Ever used Twitter | 499 | 62% |
| Have health condition that increases COVID-19 risk | 450 | 56% |
| Probably or definitely had COVID-19 | 93 | 11% |
| Knew someone who had COVID-19 | 328 | 40% |
Characteristics did not differ by experimental conditions in either the vaping or smoking experiments (all p>0.05). Missing demographic data ranged from 0.0% to 1.6%. Health conditions that increase COVID-19 risk included heart disease or history of heart attack; stroke; hypertension or high blood pressure; asthma; cancer; chronic lung disease including chronic obstructive pulmonary disease; emphysema or chronic bronchitis; obesity (body mass index ≥30 kg/m2); diabetes; liver disease including cirrhosis; chronic kidney disease; or autoimmune disease including lupus, multiple sclerosis, rheumatoid arthritis, psoriasis, Crohn’s disease, and inflammatory bowel disease.
FPL, US Federal Poverty Level for 2020.