a1 Cancer Research UK Health Behaviour Research Centre, University College London, UK
Background and aims: This study examined whether providing smokers with a personal monitor for measuring expired-air carbon monoxide (CO) concentrations would be a feasible method of achieving a reduction in smoke intake. Methods: Ten smokers were given a CO monitor and asked to use it regularly throughout the day for 6 weeks with the aim of maintaining their CO reading below 10 ppm. They were advised to use nicotine replacement therapy, but this was not provided. At baseline and follow-up, smokers were asked to comment on their use of the monitors and motivation to stop smoking. Demographic characteristics, cigarette consumption, and nicotine dependence, was also assessed. Additionally, during the first 2 weeks participants were instructed to record how often they used their CO monitor, their average readings and cigarette consumption. Results: Eight smokers had an average daily CO concentration below their baseline on at least 93% of the days in the 2 weeks of daily monitoring, while three had CO levels below 10 ppm on 36% of the days. At the 6-week follow-up, all participants’ CO concentrations were below their baseline value; two were below 10 ppm. Average daily cigarette consumption reduced from 14.1 (SD 6.03) at baseline to 9.8 (SD 4.95) during the 2 weeks of daily CO monitoring (t = 2.46, df 9, p = 0.036) and 9.5 (SD 5.50) at 6 weeks follow-up (t = 1.73, df 7, p = 0.127). Use of the CO monitors was generally found to be acceptable and to increase motivation to stop smoking completely. Five smokers attempted to quit smoking. Conclusions: Regular personal CO monitoring may be a useful method for reducing smokers’ cigarette intake and increasing their motivation to stop completely. A controlled trial with long-term follow up is warranted.