Table 1.

Characteristics of study participants.

Cross-sectional study (n = 73)Never-smokers (n = 42)E-cig users (n = 15)Smokers (n = 16)P valuea
Age, years, average (range)25 (21–30)27 (21–30)26 (21–30)0.19
Gender0.03
 Females, N (%)25 (60%)5 (33%)4 (25%)
Race0.86
 White, N (%)31 (74%)12 (80%)14 (88%)
 Black or African American, N (%)3 (7%)1 (7%)1 (6%)
 Asian, N (%)7 (17%)1 (7%)1 (6%)
 More than one race, N (%)1 (2%)1 (7%)0 (0%)
Smoking
 Former, N (%)0 (0%)12 (80%)0 (0%)<0.0001
 Current, N (%)0 (0%)0 (0%)16 (100%)
 Never, N (%)3 (20%)0 (0%)
 Years of smoking, average (range)7.5 (1–15)b6.6 (0.6–13)0.69
 Cigarettes per day, average (range)12.6 (0.7–20)b16 (10–20)0.24
 Years since last cigarettes, average (range)2.1 (0.4–4.1)b
E-cig use
 Years of e-cig use, average (range)2.6 (0.5–4)
 Puffs per day, average (range)163.3 (20–600)
 E-liquid (mL) per day, average (range)8.3 (2–20)
 Nicotine (mg/mL), average (range)10.7 (1.5–36)
  • aKruskal–Wallis (among three groups) or Mann–Whitney test (between two groups) for continuous variables; Fisher exact test for categorical variables.

  • bPrior smoking e-cig users.