The randomized study provides a number of important benefits that can never be realized in a survey study. Most importantly, the RCT can equalize between study groups the known and unknown confounding variables that may lead to invalid study results.

b. Menthol

According to a "" on the Americans for Nonsmokers Rights (ANR) web site, short-term use of electronic cigarettes impairs lung function and can cause difficulty breathing:

Stan writes: "Kelvin Choi and Jean Forester just published a of young adults that followed young adults in Minnesota for one year and examined how attitudes about e-cigarettes affected behavior. They report that one year after entering the study 7.4% of the young adults reported ever using e-cigarettes (21.6% among baseline current smokers, 11.9% among baseline former smokers, and 2.9% among baseline nonsmokers). Put another way, 11.9% of people who had quit smoking before the study started were using e-cigarettes at the end as were 2.9% of people who had never smoked. For these people, e-cigarettes were a pathway to renewed or new nicotine addiction."

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