Table 3.
Impact of vaping introduction on smoking prevalence from interrupted time series analysis, after adjusting for cigarette tax/price and plain packaging
| Settings | Vaping restrictions (least to most) | Intervention year | Coefficients after adjusting for cigarette tax/price and plain packaging | Years of observations | |||
| Underlying linear time trend | Trend change after vaping introduction | Tax/price | Constant | ||||
| Alberta, Canada (aged 18–34 years,* %) | |||||||
| Men | + | 2012 | 0.55 (−1.21 to 2.32) | −3.21 (−5.74 to –0.69, 0.027) | −0.44 (−0.96 to 0.08) | 64.59 (27.60 to 101.58) | 8 |
| Women | + | −1.30 (−2.42 to –0.17, 0.035) | −0.22 (−4.61 to 4.17) | 0.16 (−0.94 to 1.26) | 16.39 (−65.38 to 98.17) | 8 | |
| Ontario, Canada (aged 18–34 years*, %) | |||||||
| Men | + | 2012 | −0.60 (−4.17 to 2.97) | −0.81 (−3.95 to 2.34) | 0.51 (−0.55 to 1.57) | −0.95 (−66.16 to 64.27) | 8 |
| Women | + | −0.30 (−2.39 to 1.79) | −1.43 (−3.67 to 0.80) | −0.09 (−0.88 to 0.70) | 27.53 (−22.73 to 77.79) | 8 | |
| Quebec, Canada (aged 18–34 years,* %) | |||||||
| Men | ++ | 2012 | −0.62 (−2.17 to 0.93) | −4.47 (−6.72 to −2.21, 0.024) | 0.50 (0.23 to 0.77, 0.010) | 9.24 (−5.25 to 23.73) | 8 |
| Women | ++ | 0.25 (−2.55 to 3.05) | −5.62 (−8.47 to −2.77, 0.008) | 0.86 (0.58 to 1.15, 0.002) | −19.43 (−32.92 to −5.94, 0.019) | 8 | |
| British Columbia, Canada (aged 18–34 years,* %) | |||||||
| Men | ++ | 2012 | −5.80 (−7.70 to −3.89, 0.002) | 0.05 (−3.38 to 3.48) | 1.15 (0.24 to 2.06, 0.027) | −32.94 (−83.48 to 17.60) | 8 |
| Women | ++ | −0.79 (−3.26 to 1.68) | −0.12 (−2.62 to 2.37) | −0.05 (−0.61 to 0.50) | 23.21 (−9.13 to 55.56) | 8 | |
| UK (aged 16–24 years, %) | |||||||
| Men | +++ | 2011 | −2.81 (−7.22 to 1.59) | 1.88 (0.33 to 3.42, 0.031) | 7.17 (−14.70 to 29.04) | −22.63 (−171.44 to 126.19) | 8 |
| Women | +++ | −1.16 (−5.89 to 3.56) | −0.63 (−3.40 to 2.13) | 2.00 (−13.39 to 17.39) | 13.57 (−91.44 to 118.59) | 8 | |
| UK (aged 25–34 years, %) | |||||||
| Men | +++ | 2011 | 4.28 (3.23 to 5.34, 0.001) | 2.07 (1.46 to 2.68, 0.002) | −25.47 (–30.12 to –20.83, 0.000) | 202.79 (171.28 to 234.30) | 8 |
| Women | +++ | 1.29 (−1.48 to 4.06) | −0.39 (−1.67 to 0.89) | −3.90 (−17.96 to 10.16) | 50.17 (−45.78 to 146.12) | 8 | |
| Australia (aged 18–24 years, based on AHS, %) | |||||||
| Men | ++++ | 2015 | −0.68 (−2.97 to 1.60) | 3.77 (0.23 to 7.32, 0.044) | −0.01 (−0.07 to 0.03) | 29.95 (6.22 to 53.68) | 8 |
| Women | ++++ | −0.68 (−2.84 to 1.48) | −2.00 (−5.29 to 1.28) | 0.01 (−0.04 to 0.05) | 14.23 (−7.78 to 36.24) | 8 | |
| Australia (aged 25–34 years, based on AHS, %) | |||||||
| Men | ++++ | 2015 | −1.09 (−2.18 to 0.00) | −1.09 (−2.80 to 0.61) | 0.01 (−0.01 to 0.03) | 23.36 (11.95 to 34.78) | 8 |
| Women | ++++ | −0.71 (−4.78 to 3.36) | 1.57 (−4.65 to 7.79) | −0.02 (−0.11 to 0.07) | 30.06 (−11.63 to 71.74) | 8 | |
*Among young adults aged 18–34 years from 2008 to 2014 and 20–34 years from 2015 to 2018.
†Cigarette smoking prevalence in Canada and UK, and tobacco smoking prevalence in Australia.
AHS, Australian National Health Survey.