Determining Optimal Cutoffs for Exhaled Carbon Monoxide and Salivary Cotinine to Identify Smokers among Korean Americans in a Smoking Cessation Clinical Trial

Table 2

The number of participants completed each follow-up assessment and CO and cotinine measures.

Month at follow-up	1 month	3 months	6 months	12 months
Follow-up data completed	82	80	78	79
Breath CO test done	82	80	78	79
Salivary cotinine test done	na^a	80	76	72
Self-reported abstinence	69	50	42	32
Abstinence verified with biochemical measures^b	62	43	34	32

^aNot applicable. ^bDetermined by exhaled and salivary (10-30 ng/ml) except for a 1-month follow-up at which abstinence was determined by exhaled CO only.