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Published on: May 16, 2012
Validation of self-reported smoking status using saliva cotinine: a rapid semiquantitative dipstick method
Norman J Montalto1, Wayne O Wells
1Acordia National/Wells Fargo, 602 Virginia St. E., Charleston, West Virginia, 25327-1921, USA. norman.montalto@gwl.com
Purpose:
This study evaluated the performance characteristics of a novel rapid method for verifying smoking status in individuals by measurement of cotinine, the primary metabolite of nicotine, in saliva samples using an immunochromatographic strip in a "dipstick" format compared with liquid chromatography/mass spectrometry (LC/MS).
Materials And Methods:
A prospective comparison was made of smoking status as determined by measurement of cotinine in urine by LC/MS (the gold standard) and in saliva using a semiquantitative dipstick assay that uses cotinine-specific monoclonal antibodies attached to gold particles and a series of avidity traps to measure cotinine levels (saliva NicAlert). One hundred seventy-two individuals from a family practice/general medical setting agreed to participate after informed consent and institutional review board approval. Saliva NicAlert tests were done by untrained operators who followed written directions.
Results:
Comparison of smoking status as determined by urine cotinine measurement by LC/MS (50 ng/mL cutoff) with the saliva strip test results, averaged over the two operators, indicated that the saliva test strip results had a sensitivity of 99% and a specificity of 96%. Saliva NicAlert also identified four smokers who reported being nonsmokers but were confirmed to be smokers by LC/MS.
Conclusions:
The saliva NicAlert assay seems to be a valid, highly sensitive, and specific method for validating self-reported smoking status and may have clinical applications in selected medical settings.
