Table 3

Estimated percentage point changes in mean cigarette consumption per day as a function of e-cigarette use and NRT use among smokers for temporary abstinence from November 2006 to March 2016, based on ARIMAX models

All users of nicotine replacementOnly daily users of nicotine replacement
Percentage change per 1 % change in the exposure (95%  CI) P values
Use of e-cigarettes for temporary abstinence
(immediate impact)
−0.010 (−0.024 to 0.005)
0.150
−0.011 (−0.027 to 0.004)
0.146
−0.010 (−0.024 to 0.004)
0.159
−0.011 (−0.026 to 0.003)
0.135
NRT use for temporary abstinence
(immediate impact)
0.023 (−0.016 to 0.062)
0.241
0.022 (−0.020 to 0.063)
0.303
0.006 (−0.015 to 0.028) 0.5630.006 (−0.016 to 0.028)
0.585
Mass media expenditure
(immediate impact)
<0.001 (−0.001 to 0.001)
0.873
<0.001 (−0.001 to 0.001) 0.942
Total percentage change due to the exposure (95% CI) P values
Smoking ban
(pulse effect)
0.017 (−0.069 to 0.103)
0.696
0.014 (−0.071 to 0.099)
0.750
Increase in age-of-sale
(pulse effect)
−0.036 (−0.122 to 0.050)
0.415
−0.040 (−0.125 to 0.044)
0.350
Move to local authority control
(pulse effect)
−0.016 (−0.102 to 0.071)
0.721
−0.026 (−0.111 to 0.060)
0.556
Licensing for NRT for harm reduction
(pulse effect)
0.023 (−0.067 to 0.114)
0.615
0.019 (−0.070 to 0.108)
0.670
NICE guidance on harm reduction
(pulse effect)
−0.021 (−0.106 to 0.065)
0.638
−0.030 (−0.116 to 0.055)
0.483
Best fitting modelARIMAX(0,1,1)(0,0,0)12 ARIMAX(0,1,1)(0,0,0)12 ARIMAX(0,1,1)(0,0,0)12 ARIMAX(0,1,1)(0,0,0)12 ARIMAX(0,1,1)(0,0,0)12 ARIMAX(0,1,1)(0,0,0)12
Non-seasonal AR P valuesNANANANANANA
Non-seasonal MA P values<0.001<0.001<0.001<0.001<0.001<0.001
Seasonal AR P valuesNANANANANANA
Seasonal MA P valuesNANANANANANA
R2 0.650.650.650.650.640.65
Bayes factor e-cigarette (0.009 (0.1))1.01 (0.59)1.94 (0.38)1.97 (0.35)2.15 (0.41)
Bayes factor NRT (0.009 (0.1))0.15 (0.02)0.69 (0.11)1.05 (0.18)0.61 (0.08)
  • An AR(1) means that the value of a series at one point in time is the sum of a fraction of the value of the series at the immediately preceding point in time and an error component; an MA(1) means that the value of a series at one point in time is a function of a fraction of the error component of the series at the immediately preceding point in time and an error component at the current point in time.

  • AR, autoregressive; ARIMAX, Autoregressive Integrated Moving Average with Exogeneous Input; MA, moving average; NA, not applicable; NICE, National Institute for Health and Care Excellence; NRT, nicotine replacement therapy.