Table 1.

Sample characteristics (n = 68) at baseline, by study arm

Control (n = 22)16 mg ENDS (n = 25)24 mg ENDS (n = 21)P
Age, mean (SD)42.3 (14.2)43.3 (14.4)40.9 (12.3)0.8
Male (%)36%28%57%0.1
Race0.6
White (%)59%56%48%
Black or African American (%)41%40%52%
Income0.8
Less than $25k55%48%48%
More than $25k36%48%48%
Education0.04
Some HS5%12%5%
HS41%8%43%
Some college36%56%52%
College or greater18%24%0
Employed full- or part-time (%)68%44%52%0.3
Age began smoking15.8 (3.2)18.4 (4.6)19.0 (8.4)0.2
Lives with another smoker (%)27%56%33%0.3
CPD16.7 (11.3)13.9 (4.9)15.3 (8.3)0.9
Heaviness of smoking (0–6)3.1 (1.3)2.6 (1.3)2.9 (1.4)0.6
Quit attempt in past year (%)45%36%19%0.2
Lifetime # quit attempts4.0 (3.4)5.5 (8.0)3.0 (4.4)0.2
Motivation to quit smoking in next month (0–10)4.0 (3.9)5.0 (3.8)4.4 (3.1)0.6
Confidence to quit smoking (0–10)4.7 (3.0)3.4 (3.0)4.3 (3.1)0.3
Ever used e-cigarette9%4%33%0.01
Anyone you know use an e-cigarette55%52%57%0.9
Intend to use e-cigarette in future (0–10)5.4 (3.3)5.6 (2.9)5.5 (3.4)0.9