I. Inclusion criteria | II. Exclusion criteria | ||
---|---|---|---|
a. | Original peer-reviewed articles from US studies published between January 1, 2000 and March 4, 2014 | a. | Studies from clinical trials, controlled cessation programs, and clinical studies or evaluations of smokeless tobacco cessation interventions without additional follow-up beyond the originally planned timeframe of the program |
b. | Articles include estimates of at least one transition between two points in time between a combination of the following tobacco use states: exclusive cigarette smoking, exclusive smokeless tobacco use, dual use of both products, and use of neither product. | b. | Studies that do not have data on smokeless transition behaviors |
c. | Non-human studies | ||
d. | Non-English language studies | ||
e. | Commentaries or non-empirical research | ||
f. | Studies published prior to 2000 | ||
g. | Studies on e-cigarettes as a “smokeless” product |