Trial outcomes at visit 5, intent-to-treat analysis
| Control messages (n=359) | Chemical messages (n=360) | P values | ||||
| n | Mean (SD) | n | Mean (SD) | Difference (95% CI) | ||
| Primary outcome | ||||||
| Quit intentions* | 359 | 2.6 (1.1) | 360 | 2.6 (1.0) | 0.05 (−0.11 to 0.20) | 0.56 |
| Secondary outcomes | ||||||
| Negative affect†‡ | 351 | 2.0 (1.0) | 350 | 2.4 (1.1) | 0.34 (0.18 to 0.49) | <0.001 |
| Thinking about | ||||||
| The chemicals in cigarettes† | 359 | 2.5 (1.3) | 360 | 2.8 (1.2) | 0.30 (0.11 to 0.48) | 0.002 |
| The harms of smoking† | 359 | 2.8 (1.1) | 360 | 3.0 (1.0) | 0.17 (0.02 to 0.33) | 0.03 |
| The message†‡ | 351 | 2.6 (1.1) | 353 | 2.7 (1.1) | 0.01 (−0.15 to 0.17) | 0.88 |
| Quitting† | 359 | 3.1 (1.4) | 360 | 3.1 (1.2) | 0.03 (−0.16 to 0.22) | 0.75 |
| Perceived likelihood of harm from smoking† | 359 | 3.1 (0.9) | 360 | 3.2 (0.9) | 0.03 (−0.09 to 0.16) | 0.62 |
| Number of conversations about label in the past week | 359 | 1.9 (3.3) | 360 | 2.5 (4.2) | 0.57 (0.02 to 1.12) | 0.04 |
| Number of times forgoing/butting out a cigarette in past week | 359 | 5.6 (5.1) | 360 | 6.6 (5.6) | 0.94 (0.15 to 1.73) | 0.02 |