Evaluation of Biochemical Validation Measures in Determination of Smoking Status

Abstract

This study was designed to evaluate the use of salivary cotinine, salivary thiocyanate, and expired-air carbon monoxide as biochemical validation measures for assessing the smoking status of adults. The participants were 20 known non-smokers plus 216 admitted smokers and 102 proclaimed quitters participating in a clinical trial of approaches to facilitate smoking cessation. Conventional analytical procedures were utilized. By use of data from known non-smokers and admitted smokers, the sensitivity and specificity of the validation measures were as follows: salivary cotinine, 99% and 100%; expired-air carbon monoxide, 96% and 100%; and salivary thiocyanate, 67% and 95%, respectively. The salivary cotinine and expired-air carbon monoxide tests confirmed smoking cessation for 55% and 74%, respectively, of the proclaimed quitters. The length of time since quitting was significantly related to the results observed with the latter measures. Consideration of these observations along with various practical factors suggests that expired-air carbon monoxide assays may be the validation measure of choice for most clinical trials.

Improvement in blood pressure after short-term inorganic nitrate supplementation is attenuated in cigarette smokers compared to non-smoking controls

“…However, it has been suggested that expired [CO] might be a more sensitive bio-marker of smoking status than salivary/plasma [SCN -] [50][51][52]. Expired [CO] was 200% higher in the smokers compared to the non-smokers in all experimental conditions in this study.…”

Nasal Mucociliary Clearance in Subjects With COPD After Smoking Cessation

“…23,48,49 This research, concurs with the observation by Chatkin et al 50 noting elevated exhaled CO levels in current smokers with normal lung function and smokers with COPD compared with nonsmokers with normal lung function and ex-smokers with COPD. The exhaled CO levels may be useful in monitoring changes in heme oxygenase enzyme activity in vivo, which might reflect inflammation or oxidative stress level in patients with airway and systemic inflammation.…”

Current research on cigarette toxicity: critical appraisal in view of clinical laboratory

“…29 Carbon monoxide levels, measured by breathe analyser, in expired air, showed 96% sensitivity and 100% specificity in determining the smoking status among smokers and nonsmokers. 30 It confirmed smoking cessation (quitters) in 74% of the past smokers. 30 However, half-life of carbon monoxide is very short (only 4-6 hours) and could not be used in confirming smoking abstinence over more than a few hours.…”

“…30 It confirmed smoking cessation (quitters) in 74% of the past smokers. 30 However, half-life of carbon monoxide is very short (only 4-6 hours) and could not be used in confirming smoking abstinence over more than a few hours. 31 …”

“…The main limitation was the sensitivity and specificity of the assay, which was found to be lowered compared to expired carbon monoxide and other new methods. 30 Salivary thiocyanate, measured by colorimetric method, showed only 67% sensitivity and 95% specificity in determining the smoking status among smokers and non-smokers. 30 The other important limitation of the measurement is that the thiocyanate is present in several human diets and, therefore, there is always a chance of introducing false positive error in its measurement.…”