Table 1 Summary characteristics of adjusted studies for age of initiation of cigarette smoking among individuals with non-regular use of e-cigarettes (n = 1)
Citation | Study design | Definition of individuals who use e-cigarettes | Definition of individuals who do not use e-cigs | Definition of initiation of cigarette smoking |
|---|---|---|---|---|
McCabe et al. [75] | Cross-sectional analytic | Individuals not smoking cigarettes with current e-cig use defined as response of ≥ 1 to question, “During the last 30 days, on how many occasions (if any) have you used e-cigs?” | Individuals not smoking cigarettes with response of 0 to question, “During the last 30 days, on how many occasions (if any) have you used e-cigs?” | Age in yrs given in response to the question “When, if ever did you smoke your first cigarette?” Age in yrs given in response to question, “When, if ever, did you smoke cigarettes on a daily basis?” |