Table 1 Definitions and sample sizes of adverse transitioners and initiators from classification of smoking stages.

Initiators
Smoker stage at wave 3	Never smoked	Experimental	Intermittent	Regular
Smoker stage at wave 1
Never smoked	1,261	440	106	186
Experimental	−	−	−	−
Intermittent	−	−	−	−
*Never smoked  = 63.3% (n = 1261); initiators  = 36.7% (n = 732); total number = 1993
Adverse transitioners
Smoker stage at wave 3	Never smoked	Experimental	Intermittent	Regular
Smoker stage at wave 1
Never smoked	1,261	440	106	186
Experimental	−	−	162	235
Intermittent	−	−	−	307
*Never smoked  = 46.8% (n = 1261); adverse transitioners  = 53.2% (n = 1436); total number = 2697

Adverse transitioners include initiators.