The only thing their study really found was that among 9,909 never cigarette smoking teens at baseline, 11 ever users of an e-cigarette, 3 ever users of smokeless tobacco, 8 ever users of hookah, 7 ever users of a cigar, and 15 ever users of two or more OTP had smoked a cigarette a year later.
The 2014 NYTS found that 22% of teens (i.e. 6th-12th graders) had "ever smoked" a cigarette, and that 6.1% of teens (or 27.7% of ever cigarette smokers) had smoked a cigarette in the "past 30 days".
Had the UCSF study included "ever cigarette smokers" in their study, the number of
"ever cigarette smokers" at baseline would have been about 2,180 (9,909 x .22 = 2,180).
Assuming that 27.7% of those "ever cigarette smokers" became a "past 30 day" cigarette smoker a year later, 604 "ever smokers" (2,108 x .277 = 604) would have been current cigarette smokers (i.e. past 30 days) a year later.
So if the 2014 PATH and 2014 NYTS data were the same (in fact they were very similar), and if the UCSF researchers had appropriately included "ever cigarette smokers" in their study at baseline, there would be a total of
823 "current cigarette smokers" (219 + 604 = 823) a year later, including:
604 "ever cigarette smokers",
175 "never tobacco users",
11 "ever e-cigarette users",
3 "ever smokeless tobacco users",
8 "ever hookah users",
7 "ever cigar users, and
15 "ever users of two or more OTP"
823 total
Had UCSF activists ethically conducted their study, a correct press release headline would have said
"Study finds teens who "ever smoked" a cigarette are 55 times more likely than
never smoking teens who "ever used" an e-cigarette to become a "current cigarette smoker" the next year."