The mobile-phone-based iCOTM Smokerlyzer®: Comparison with the piCO+ Smokerlyzer® among smokers undergoing methadone-maintained therapy
More details
Hide details
Department of Psychological Medicine, University of Malaya Center of Addiction Sciences (UMCAS), Kuala Lumpur, Malaysia
National Institute for Health Innovation, The University of Auckland, Auckland, New Zealand
Department of Social and Preventive Medicine, University of Malaya, Kuala Lumpur, Malaysia
Anne Yee   

Department of Psychological Medicine, University of Malaya Center of Addiction Sciences (UMCAS), University of Malaya, 50603 Kuala Lumpur, Malaysia
Publish date: 2019-09-09
Tob. Induc. Dis. 2019;17(September):65
The mobile-phone-based Bedfont iCOTM Smokerlyzer® is of unknown validity and reproducibility compared to the widely-used piCO+ Smokerlyzer®. We aimed to compare the validity and reproducibility of the iCOTM Smokerlyzer® with the piCO+ Smokerlyzer® among patients reducing or quitting tobacco smoking.

Material and Methods:
Methadone-maintained therapy (MMT) users from three centers in Malaysia had their exhaled carbon monoxide (eCO) levels recorded via the piCO+ and iCOTM Smokerlyzers®, their nicotine dependence assessed with the Malay version of the Fagerström Test for Nicotine Dependence (FTND-M), and daily tobacco intake measured via the Opiate Treatment Index (OTI) Tobacco Q-score. Pearson partial correlations were used to compare the eCO results of both devices, as well as the corresponding FTND-M scores.

Among the 146 participants (mean age 47.9 years, 92.5% male, and 73.3% Malay ethnic group) most (55.5%) were moderate smokers (6–19 cigarettes/ day). Mean eCO categories were significantly correlated between both devices (r=0.861, p<0.001), and the first and second readings were significantly correlated for each device (r=0.94 for the piCO+ Smokerlyzer®, p<0.001; r=0.91 for the iCOTM Smokerlyzer®, p<0.001). Exhaled CO correlated positively with FTND-M scores for both devices. The post hoc analysis revealed a significantly lower iCOTM Smokerlyzer® reading of 0.82 (95% CI: 0.69–0.94, p<0.001) compared to that of the piCO+ Smokerlyzer®, and a significant intercept of -0.34 (95% CI: -0.61 – -0.07, p=0.016) on linear regression analysis, suggesting that there may be a calibration error in one or more of the iCOTM Smokerlyzer® devices.

The iCOTM Smokerlyzer® readings are highly reproducible compared to those of the piCO+ Smokerlyzer®, but calibration guidelines are required for the mobile-phone-based device. Further research is required to assess interchangeability.

The authors thank the Malaysian National Anti-Drug Agency (Agensi Anti-Dadah Kebangsaan, AADK) for its participation, support and cooperation. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of AADK.
The authors declare that they have no competing interests, financial or otherwise, related to the current work. C. Bullen reports personal fees from Johnson & Johnson KK Consumer Company Japan, outside the submitted work. A. Nordin reports grants from Johnson & Johnson Malaysia and personal fees from Lundbeck Malaysia, outside the submitted work. The rest of the authors have also completed and submitted an ICMJE form for disclosure of potential conflicts of interest.
This work was supported by a University of Malaya grant GC004B-HTM. The funders had no role in the analysis or interpretation of the study or its results.
C.B. conceived the idea for this study. A.Y., H.Y.W., M.D. and M.S. conceptualized the research aims and analytic plan, and, together with A.S.A.N, interpreted the results. All authors contributed to the writing of the manuscript and approved its final version.
Not commissioned; externally peer reviewed.
Bittoun R. Carbon Monoxide Meter: The Essential Clinical Tool — the ‘Stethoscope’ — of Smoking Cessation. J Smok Cessat. 2008;3(2):69-70. doi:10.1375/jsc.3.2.69.
Krishnan N, Elf JL, Chon S, Golub JE. COach2Quit: A pilot randomized controlled trial of a personal carbon monoxide monitor for smoking cessation. Nicotine Tob Res. 2018; doi:10.1093/ntr/nty182.
Bedfont Scientific Ltd. piCO+TM Smokerlyzer®: Operating manual. Published June, 2014. Accessed May 7, 2019.
Raiff BR, Faix C, Turturici M, Dallery J. Breath carbon monoxide output is affected by speed of emptying the lungs: Implications for laboratory and smoking cessation research. Nicotine Tob Res. 2010;12(8):834-838. doi:10.1093/ntr/ntq090.
Meredith SE, Robinson A, Erb P, et al. A mobile-phone-based breath carbon monoxide meter to detect cigarette smoking. Nicotine Tob Res. 2014;16(6):766-773. doi:10.1093/ntr/ntt275.
Erb P, Raiff BR, Meredith SE, Dallery J. The accuracy of a lower-cost breath carbon monoxide meter in distinguishing smokers from non-smokers. J Smok Cessat. 2015;10(1):59-64. doi:10.1017/jsc.2013.37.
Bedfont Scientific Limited Ltd. iCO™ Smokerlyzer®: User Manual. Published November, 2015. Accessed May 7, 2019.
Guydish J, Passalacqua E, Tajima B, Chan M, Chun J, Bostrom A. Smoking prevalence in addiction treatment: A review. Nicotine Tob Res. 2011;13(6):401-411. doi:10.1093/ntr/ntr048.
Zirakzadeh A, Shuman C, Stauter E, Hays JT, Ebbert JO. Cigarette smoking in methadone-maintained patients: an up-to-date review. Curr Drug Abuse Rev. 2013;6(1):77-84. doi:10.2174/1874473711306010009.
Yee AHA, Ng CG, Rusdi AR. Validation of the Malay version of Fagerstrom test for nicotine dependence (FTND-M) among a group of male staffs in a University Hospital. MJP. 2011;20(1). Accessed December 8, 2017.
Ng CG, Yee AHA. Exhaled carbon monoxide levels among Malaysian male smokers with nicotine dependence. Southeast Asian J Trop Med Public Health. 2012;43(1):212-218.
Darke S, Ward J, Hall W, Heather N, Wodak A. Opiate Treatment Index (OTI) Manual. Technical Report 11. Sydney: National Drug and Alcohol Research Centre; 1991. Accessed July 8, 2019.
Frosch DL, Shoptaw S, Nahom D, Jarvik ME. Associations between tobacco smoking and illicit drug use among methadone-maintained opiate-dependent individuals. Exp Clin Psychopharmacol. 2000;8(1):97-103.
Neumann T, Rasmussen M, Heitmann BL, Tønnesen H. Gold standard program for heavy smokers in a real-life setting. Int J Environ Res Public Health. 2013;10(9):4186-4199. doi:10.3390/ijerph10094186.
Karelitz JL, Michael VC, Perkins KA. Analysis of agreement between expired-air carbon monoxide monitors. J Smok Cessat. 2017;12(2);105-112. doi:10.1017/jsc.2015.18.