Sensitivity and specificity of saliva thiocyanate and cotinine for cigarette smoking: a comparison of two collection methods.

Saliva samples returned by mail were compared to duplicates returned by interviewers in terms of the sensitivity and specificity of cotinine and thiocyanate analyses performed on those samples to detect tobacco use. Compared to the samples returned by interviewers, those returned through the mail were slightly lower in specificity but similar in sensitivity. These findings confirm that saliva samples do not deteriorate during transit via the postal service, although substantial questions remain that concern the validity of such samples in the evaluation of cessation programs.