Results from logistic regression difference in difference analyses of impact of policy implementation on self-reported exposure to smoking in vehicles
| AOR (95% CI) | Absolute % difference (95% CI) | |
| Scotland 2012–2014 | 0.34 (0.15 to 0.80) | −0.45 (-2.70 to 1.80) |
| Scotland 2014–2016 | 0.25 (0.07 to 0.79) | 0.00 (-1.05 to 1.06) |
| England 2012–2014 | 1.00 (0.82 to 1.22) | −1.04 (-3.34 to 1.27) |
| England 2014–2016 (policy implementation) | 0.28 (0.21 to 0.37) | −4.11 (-4.91 to −3.31) |
| Age 13 years | ref | ref |
| Age 14 years | 1.01 (0.80 to 1.28) | 0.04 (-0.77 to 0.84) |
| Age 15 years | 1.22 (0.99 to 1.51) | 0.74 (-0.05 to 1.53) |
| Boys | ref | ref |
| Girls | 1.61 (1.34 to 1.93) | 1.75 (1.07 to 2.43) |
| Not deprived group | ref | ref |
| Deprived group | 1.98 (0.82 to 1.21) | 2.53 (1.76 to 3.29) |
Absolute % differences derived from marginal effect compared with baseline.
AOR, adjusted odds ratio.