Mobile, Remote, and Individual Focused: Comparing Breath Carbon Monoxide Readings and Abstinence Between Smartphone-Enabled and Stand-Alone Monitors. Issue 4 (6th October 2020)

• Record Type: Journal Article
• Authors: Tuck, Breanna M; Karelitz, Joshua L; Tomko, Rachel L; Dahne, Jennifer; Cato, Patrick; McClure, Erin A
• Is Part Of: Nicotine & tobacco research. Volume 23:Issue 4(2021)
• Page Start: 741
• Page End: 747
• Publication Date: 2020-10-06
• Subjects: Nicotine -- Periodicals; Tobacco -- Research -- Periodicals; Tobacco habit -- Periodicals; Nicotine -- Periodicals; Tobacco -- Periodicals; Smoking -- Periodicals; 613.85
• DOI: 10.1093/ntr/ntaa203
• Languages: English
• ISSNs: 1462-2203

Abstract

Abstract: Introduction: Newly available, smartphone-enabled carbon monoxide (CO) monitors are lower in cost than traditional stand-alone monitors and represent a marked advancement for smoking research. New products are promising, but data are needed to compare breath CO readings between smartphone-enabled and stand-alone monitors. The purpose of this study was to (1) determine the agreement between the mobile iCO (Bedfont Scientific Ltd) with two other monitors from the same manufacturer (Micro + pro and Micro + basic) and (2) determine optimal, monitor-specific, cotinine-confirmed abstinence cutoff values. Methods: Adult (≥18) smokers ( n = 26) and nonsmokers ( n = 21) provided three breath CO samples (using three different monitors) in each of 10 sessions, and urine cotinine was measured for gold standard determination of abstinence. CO comparisons ( N = 437) were analyzed using regression-based Bland–Altman Analysis of Agreement; receiver operating characteristics curves were used to determine optimal abstinence cutoffs. Results: Bland–Altman analyses indicated that the iCO monitor provided higher CO results than both Micro + monitors. Sensitivity and specificity analyses showed that the optimal CO cutoff for determining abstinence was <3 ppm for the Micro + pro (88% sensitivity, 93% specificity) and Micro + basic (83% sensitivity, 98% specificity), but was higher for the iCO (<6 ppm; 73% sensitivity, 100% specificity). Conclusions: Relative to both Micro + monitors, the smartphone-enabled iCO provided systematically higher CO values and required a higher cutoff to reliably determine smoking abstinence. This does not indicate that CO values obtained using the iCO are not valid; instead, these results suggest that monitor-specific abstinence cutoffs are needed to ensure accurate bioverification of smoking status. Implications: Results from this study indicate that CO values from the smartphone-enabled iCO should not be used interchangeably with the stand-alone Micro + pro and Micro + basic, particularly when lower CO values (<10 ppm) are critical (ie, determination of abstinence vs confirming smoking status for study inclusion). Optimal CO cutoffs recommended for determining abstinence on Micro + and iCO monitors are at <3 and <6 ppm, respectively.