Older brands* (N=251) | Newer brands† (N=215) | Older vs newer brands p value | ||||
---|---|---|---|---|---|---|
Top-5 brands (N=5) % | Other brands (N=246) % | Top-5 vs others p value | Older brands combined (N=251)% | Newer brands (N=215)% | ||
% listing ingredients | 100.0 | 78.0 | <0.01 | 78.5 | 71.2 | 0.07 |
Mean number of ingredients listed | 5.2 | 4.62 | 0.52 | 4.6 | 4.0 | <0.05 |
Type of ingredients | ||||||
Nicotine | 100.0 | 93.2 | <0.01 | 93.4 | 81.7 | <0.05 |
Propylene glycol | 80.0 | 84.9 | 0.82 | 84.8 | 92.8 | 0.06 |
Vegetable glycerine/glycerol | 80.0 | 59.4 | 0.36 | 59.9 | 88.2 | <0.01 |
Flavouring | 100.0 | 70.3 | <0.01 | 71.1 | 65.4 | 0.45 |
Water | 20.0 | 47.9 | 0.24 | 47.2 | 33.3 | <0.01 |
*Active on the internet in 2012 and 2014.
†Active on the internet in 2014 but not 2012.