Comparable Sensitivities of Urine Cotinine and Breath Carbon Monoxide at Follow-Up Time Points of Three Months or More in a Smoking Cessation Trial

Abstract

To control for likely overreporting of abstinence in clinical trials of smoking cessation aids, field convention demands the corroboration of subjects’ self-reports by a biochemical/pharmacological marker. It is, however, currently debated if urinary cotinine (UC), a metabolite of nicotine, should be preferred because of its higher sensitivity, although sample collection for and analysis of cotinine are much more expensive and work intensive than carbon monoxide (CO) measurements in exhaled air. In the present study, it turned out that UC was of only moderately higher sensitivity than CO (99.4% vs. 96.3%; p = 0.02), the difference being significant only at group sizes of >164. UC identified participants as smokers who escaped CO detection in 4.9% of the cases, whereas CO identified smokers who escaped UC detection in 2.7% of the cases (p = 0.014). Our findings suggest that the costs/disadvantages of using UC instead of CO may outweigh its benefit as a pharmacological marker of (non)smoking status.

Intervention study for smoking cessation in Spanish college students: pragmatic randomized controlled trial

“…Secondly, self‐reports of abstinence were verified biochemically by urine cotinine measurements. Although the carbon monoxide (CO) in exhaled air is considered adequate for validating smoking abstinence , some authors point out that cotinine validation is more reliable than CO in order to confirm abstinence incidence and is considered the ‘best practice’ indicator in smoking cessation trials , confirming a deceit rate of zero. Thirdly, intention‐to‐treat analyses were applied, assuming that the subjects who did not attend the evaluation session had not stopped smoking.…”

Carbon monoxide in exhaled breath testing and therapeutics

“…Recent studies suggest that eCO measurements may represent a reliable and cost-effective alternative to testing of urinary cotinine, as a method for monitoring smoking cessation [88]. eCO values are typically increased in smokers with normal lung function relative to non-smokers [48].…”

How Low Should You Go? Determining the Optimal Cutoff for Exhaled Carbon Monoxide to Confirm Smoking Abstinence When Using Cotinine as Reference

“…Although the short half-life of CO (2-3 hr) limits the range to detection to about 24 hr (e.g., Perkins, Karelitz, & Jao, 2013), CO remains one of the least expensive and invasive methods Advance Access publication June 2, 2014 for verifying smoking abstinence. CO has comparable detection rates to cotinine for short-term abstinence (Fritz et al, 2010), with cutoffs of 8-10 parts per million (ppm) commonly cited as indicative of recent smoking (SRNT Subcommittee on Biochemical Verification, 2002).…”