Table 1.
Baseline characteristics of participants in the Quit with US trial.
| Characteristic | Quit with US (n = 137), n (%) |
Control (n = 136), n (%) |
Total (n = 273), n (%) |
p-Value |
|---|---|---|---|---|
| Sex | ||||
| Male | 80 (58.4) | 84 (61.8) | 164 (60.1) | 0.622 |
| Female | 57 (41.6) | 52 (38.2) | 109 (39.9) | |
| Age, mean (SD), years | 21.20 (1.63) | 20.93 (1.60) | 21.06 (1.62) | 0.179 |
| Age at cigarette initiation, mean (SD), years | 17.14 (2.29) | 16.93 (2.56) | 17.04 (2.43) | 0.486 |
| Cigarette smoking frequency | ||||
| Daily smokers | 75 (54.7) | 83 (61.0) | 158 (57.9) | 0.327 |
| Nondaily smokers | 62 (45.3) | 53 (39.0) | 115 (42.1) | |
| Daily cigarette consumption | ||||
| ≤10 | 123 (89.8) | 121 (89.0) | 244 (89.4) | 0.768 |
| 11–20 | 13 (9.5) | 15 (11.0) | 28 (10.3) | |
| 21–30 | 1 (0.7) | 0 | 1 (0.4) | |
| mean (SD) | 5.74 (4.93) | 5.87 (4.63) | 5.80 (4.77) | 0.822 |
| Time to first cigarette after waking up | ||||
| ≤5 min | 18 (13.1) | 15 (11.0) | 33 (12.1) | 0.336 |
| 6–30 min | 14 (10.2) | 24 (17.6) | 38 (13.9) | |
| 31–60 min | 22 (16.1) | 18 (13.2) | 40 (14.6) | |
| >60 min | 83 (60.6) | 79 (58.1) | 162 (59.3) | |
| HSI score 1 | ||||
| 0–2 (low nicotine dependence) | 117 (85.4) | 118 (86.8) | 235 (86.1) | 1.000 |
| 3–4 (moderate nicotine dependence) | 19 (13.9) | 18 (13.2) | 37 (13.6) | |
| 5–6 (high nicotine dependence) | 1 (0.7) | 0 | 1 (0.4) | |
| mean (SD) | 0.87 (1.22) | 0.93 (1.22) | 0.90 (1.22) | 0.695 |
| Past year cigarette quit attempt | ||||
| Yes | 102 (74.4) | 96 (70.6) | 198 (72.5) | 0.500 |
| No | 35 (25.6) | 40 (29.4) | 75 (27.5) | |
| Cigarette quit intention | ||||
| Ready to quit smoking | 35 (25.6) | 32 (23.5) | 67 (24.5) | 0.779 |
| In the next 30 days | 102 (74.4) | 104 (76.5) | 206 (75.5) | |
| Smartphone operating system | ||||
| iOS | 68 (49.6) | 74 (54.4) | 142 (52.0) | 0.468 |
| Android | 69 (50.4) | 62 (45.6) | 131 (48.0) | |
| Smartphone use frequency per day | ||||
| ≤10 times | 13 (9.5) | 18 (13.2) | 31 (11.4) | 0.456 |
| 11–20 times | 36 (26.3) | 42 (30.9) | 78 (28.6) | |
| 21–30 times | 45 (32.8) | 43 (31.6) | 88 (32.2) | |
| ≥31 times | 43 (31.4) | 33 (24.3) | 76 (27.8) | |
| Smartphone use period per time | ||||
| ≤15 min | 21 (15.3) | 27 (19.8) | 48 (17.6) | 0.541 |
| 16–30 min | 45 (32.8) | 52 (38.2) | 97 (35.5) | |
| 31–45 min | 22 (16.1) | 20 (14.7) | 42 (15.4) | |
| 46–60 min | 26 (19.0) | 21 (15.4) | 47 (17.2) | |
| ≥61 min | 23 (16.8) | 16 (11.8) | 39 (14.3) | |
| Previous use of smartphone app for smoking cessation | ||||
| Yes | 0 (0) | 0 (0) | 0 (0) | - |
| No | 137 (100.0) | 136 (100.0) | 273 (100.0) | |
| Exhaled CO concentration, mean (SD), ppm | 9.34 (4.79) | 9.48 (4.33) | 9.41 (4.56) | 0.787 |
| Scores on knowledge and attitudes | ||||
| Knowledge of smoking and smoking cessation, 2 mean (SD) | 12.82 (1.48) | 12.60 (1.56) | 12.71 (1.52) | 0.228 |
| Attitudes toward smoking and smoking cessation, 3 mean (SD) | 39.74 (2.99) | 39.18 (3.28) | 39.46 (3.14) | 0.141 |
HIS, Heaviness of Smoking Index; CO, carbon monoxide; ppm, parts per million; 1 The scores ranged between 0 and 6, with high scores conveying high nicotine dependence. 2 The scores ranged between 0 and 15, with high scores conveying better knowledge on smoking and smoking cessation. 3 The scores ranged between 15 and 45, with high scores conveying positive attitudes toward smoking and smoking cessation.