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

Figure 1

(a) Areas under the ROC curve by four different cutoffs of exhaled CO using salivary cotinine with a cutoff of level 1 (10-30 ng/ml) as the reference at 3 months postquit. (b) Areas under the ROC curve by four different cutoffs of exhaled CO using salivary cotinine with a cutoff of level 2 (30-100 ng/ml) as the reference at 3 months postquit.

(a)

(b)