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

Table 4

Sensitivity and specificity of salivary cotinine cutoff levels 1 and 2 at each follow-up.

Cotinine cutoff (ng/ml)	Follow-up	Sensitivity	Specificity	ROC area
Level 1: 10-30	3-M	0.978	0.651	0.815
	6-M	0.982	0.647	0.814
	12-M	1.000	0.844	0.922
Level 2: 30-100	3-M	0.956	1.000	0.978
	6-M	0.944	1.000	0.972
	12-M	0.912	1.000	0.956

The number of participants varied at each follow-up: 80 at 3 months, 76 at 6 months, and 72 at 12 months.