Table 2.

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

	Quit success rate			Overall quit rate
	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 e‐cigarette use during a quit attempt	0.060	0.043 to 0.078	< 0.001	0.050	0.031 to 0.069	< 0.001
Mass media	0.143	0.055 to 0.231	0.001	0.212	0.1179 to 0.305	< 0.001

	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)	0.400	0.126 to 0.674	0.004	0.472	0.186 to 0.759	0.001
Increase in age of sale (temporary impact in fourth quarter of 2007)	0.318	0.041 to 0.596	0.025	0.439	0.147 to 0.731	0.003
Move to local authority (temporary impact in second quarter of 2013)	−0.216	−0.489 to 0.056	0.120	−0.020	−0.308 to 0.269	0.895
Tobacco control directive (temporary impact in the second quarter of 2016)	0.181	−0.091 to 0.453	0.192	0.130	−0.157 to 0.417	0.375
Model Lag for e‐cigarettes Lag for mass media Adjusted R 2	ARIMA(0,1,1)(1,0,0)4 No lag No lag 48.61			ARIMA(0,1,1)(1,0,0)4 No lag No lag 47.47

ARIMA = autoregressive integrated moving average analysis; ARIMAX = Autoregressive Integrated Moving Average with Exogeneous Input; CI = confidence interval.