Table 1

Descriptive statistics of participant characteristics in study sample*

Participant characteristicsN (%) or M (SD)
Demographics
Female gender, N (%)35 (35.0)
Age, mean (SD), years25.4 (4.4)
Race/ethnicity, N (%)
 Hispanic22 (22.0)
 White29 (29.0)
 Black25 (25.0)
 Asian15 (15.0)
 Other9 (9.0)
Tobacco product use characteristics
Combustible cigarette smoking status†
 Never smoker22 (22.0)
 Former smoker‡25 (25.0)
 Current smoker§53 (53.0)
Salivary cotinine semi-quantitative level¶2.85 (1.22)
Carbon monoxide, ppm**5.00 (5.51)
PSECDI e-cigarette dependence score, mean (SD)7.01 (4.51)
Puffs per day, mean (SD)74.3 (124.3)
Nicotine concentration typically used, mean (SD)8.77 (13.92)
Duration of e-cigarette use, mean (SD), months19.8 (14.4)
E-cigarette device type typically used, N (%)
 Cig-a-like12 (12)
 Tank/pen30 (30)
 Advanced personal vaporizer/mod58 (58)
Preferred e-cigarette flavour, N (%)
 Fruit or dessert80 (80.0)
 Menthol13 (13.0)
 Tobacco7 (7.0)
  • *N=100.

  • †Never smokers: smoked <100 cigarettes lifetime, former smokers: smoked ≥100 cigarettes but did not smoke in last 30 days; current smokers: smoked ≥100 cigarettes lifetime and smoked in last 30 days.

  • ‡Of the former smokers, 10 preferred menthol-flavoured cigarettes and 15 preferred non-mentholated cigarettes when they smoked.

  • §Of the current smokers, 23 preferred menthol-flavoured cigarettes and 30 preferred non-mentholated cigarettes.

  • ¶NicAlert Strip (range 1–6; 0=0–10, 1=10–30, 2=30–100, 3=100–200, 4=200–500, 5=500–1000, 6= >1000 ng/mL).

  • **Carbon monoxide was significantly higher in participants who were current smokers (M(SD)=7.04 (5.95)) than former (M(SD)=2.40 (3.04)) and never (M(SD)=3.05 (4.73)) smokers (ps<0.001).

  • e-cigarette, electronic cigarette; PSECDI, Penn State Electronic Cigarette Dependence Index.