T-test results comparing exposed to unexposed participants before and after PSM
| Before PSM | p Value | ||||
| Exposed n=215 | Unexposed n=185 | ||||
| Mean | SD | Mean | SD | α | |
| Behaviour | 3.43 | 0.90 | 3.24 | 0.00 | 0.04 |
| Intention to wear a helmet | 6.04 | 1.70 | 5.63 | 1.83 | 0.02 |
| Planning | 3.11 | 0.88 | 2.86 | 0.95 | 0.01 |
| Action self-efficacy | 3.54 | 0.78 | 3.54 | 0.98 | 0.01 |
| Outcome expectancies | 3.11 | 0.56 | 2.92 | 0.68 | 0.003 |
| Intention to comply with the law | 5.69 | 1.73 | 5.40 | 1.82 | 0.11 |
| Maintenance self-efficacy | 3.42 | 0.79 | 3.17 | 0.93 | 0.01 |
| Recovery self-efficacy | 3.51 | 0.81 | 3.32 | 0.89 | 0.03 |
| RR perception | −0.46 | 1.25 | −0.43 | 1.26 | 0.81 |
| Absolute risk perception | 0.14 | 1.26 | 0.19 | 1.40 | 0.74 |
| Perceived risk of breaking the law | 3.29 | 1.94 | 3.45 | 1.89 | 0.41 |