Measuring tobacco use in a prison population

Area of Science:

• Biomedical Science
• Public Health
• Addiction Research

Background:

• Prisons are key settings for smoking cessation interventions due to high tobacco use and interest in quitting.
• Effective evaluation of cessation programs requires valid measurement of tobacco use among prisoners.
• Limited research exists on validated tobacco use measures specifically within correctional facilities.

Purpose of the Study:

• To evaluate the accuracy of three common tobacco use measures in a prison population.
• To identify optimal cutpoints for exhaled carbon monoxide (eCO) and salivary cotinine (EIA and LC/MS/MS) in male prisoners.
• To provide evidence for selecting reliable biomarkers for tobacco use assessment in correctional settings.

Main Methods:

• Interviews and biochemical assessments were conducted with 200 male prisoners.
• Exhaled carbon monoxide (eCO), salivary cotinine via enzyme immunoassay (EIA), and salivary cotinine via liquid chromatography/tandem mass spectrometry (LC/MS/MS) were analyzed.
• Self-reported tobacco use served as the reference standard, with Youden index maximization used to determine optimal cutpoints.

Main Results:

• Exhaled carbon monoxide (eCO) showed good discrimination (cutpoint >= 4 ppm, sensitivity 88.3%, specificity 94.9%).
• Salivary cotinine EIA performed better than eCO (cutpoint >= 10 ng/ml, sensitivity 92.2%, specificity 94.3%).
• Salivary cotinine LC/MS/MS demonstrated the highest accuracy (cutpoint >= 9 ng/ml, sensitivity 98.6%, specificity 97.8%).

Conclusions:

• eCO had the lowest performance as a standalone measure, though repeated testing may improve validity.
• Salivary cotinine EIA has limitations as a standalone test due to false negatives but can reduce costs in a two-stage screening approach.
• Salivary cotinine LC/MS/MS, despite higher cost, is the most accurate standalone biomarker for assessing tobacco use in prisoners.