Figure 1.

Classification of Tobacco Smokers According to the Centers for Disease Control and Prevention (CDC), Atlanta, United States. (Ever smokers – Person who had smoked tobacco products in their lifetime; Never smokers - Persons who had not smoked a tobacco product (cigarette, cigar, beedi, pipe) in their lifetime; Current smokers - Ever smokers who were currently smoking tobacco products; Former smoker - Ever smokers who were not smoking tobacco products during the last 30 days; Daily smokers - Ever smokers who were smoking tobacco products daily; Non-daily smokers - Ever smokers who were smoking tobacco products on a non-daily basis)