Table 1.

Adjusted estimated percentage point changes in quitting activities and cigarette consumption as a function of current e‐cigarette use, based on ARIMAX models.

	Quit attempts			Overall quit rate			Average cigarette consumption per day
	Percentage change per 1% change in the exposure	95% CI	P‐value	Percentage change per 1% change in the exposure	95% CI	P‐value	Percentage change per 1% change in the exposure	95% CI	P‐value
Prevalence of current e‐cigarette use	0.011	–0.046 to 0.069	0.698	0.054	0.032 to 0.076	< 0.001	0.019	–0.043 to 0.082	0.542
Mass media	0.026	−0.014 to 0.066	0.196	0.214	0.118 to 0.309	< 0.001	−0.005	−0.032 to 0.023	0.739

	Total change due to the exposure	95% CI	P‐value	Total change due to the exposure	95% CI	P‐value	Total change due to the exposure	95% CI	P‐value
Smoking ban (temporary impact in third quarter of 2007)	−0.026	−0.133 to 0.081	0.636	0.480	0.187 to 0.772	0.001	−0.034	−0.084 to 0.017	0.193
Increase in age of sale (temporary impact in fourth quarter of 2007)	0.036	−0.070 to 0.143	0.503	0.446	0.147 to 0.745	0.003	0.011	−0.041 to 0.064	0.674
Move to local authority (temporary impact in second quarter of 2013)	0.041	−0.055 to 0.138	0.403	−0.027	−0.320 to 0.265	0.854	0.018	−0.034 to 0.071	0.498
Tobacco control directive (temporary impact in the second quarter of 2016)	−0.078	−0.169 to 0.012	0.089	0.147	−0.143 to 0.436	0.322	−0.039	−0.106 to 0.029	0.261
Model Lag for e‐cigarettes Lag for mass media Adjusted R 2	ARIMA(0,1,0)(1,0,0)4 No lag No lag 65.47			ARIMA(0,1,1)(1,0,0)4 No lag No lag 45.97			ARIMA(0,1,1)(1,0,0)4 No lag No lag 92.34

ARIMA = autoregressive integrated moving average analysis; ARIMAX = autoregressive integrated moving average with exogeneous input; CI = confidence interval.