Feasibility of using stopWatch smartwatch system for passive detection of cigarette smoking in the workplace

Background: A number of different systems are available for passive detection of cigarette smoking, but few studies have reported the feasibility of using these in free-living conditions, and none so far have reported specifically on the feasibility of using these in workplace settings. Methods: We conducted a feasibility study of using stopWatch, a smartwatch-based system for passive detection of cigarette smoking, in workers in the construction industry. Participants wore stopWatch for three days midweek at work. Some also wore for three days over a weekend at home. They also kept paper diaries of cigarettes smoked. Results: Six cigarette smokers and two vapers were recruited. Mean number of cigarettes smoked per day was 6.1 and stopWatch detected on average 31% of these. Insufficient data were available for meaningful comparison of performance at work and home. No occurrences of vaping were detected as cigarette smoking by stopWatch. Discussion: The percentage of cigarettes smoked detected by stopWatch was lower than previously reported in free-living conditions (71%). We identified a number of practical reasons for this, including not keeping the smartwatch battery properly charged, the stopWatch application not being restarted correctly after the battery ran flat, and participants not wearing the smartwatch correctly. We make recommendations for addressing these issues.Conclusion: This is the first study of the feasibility of using a system for passive detection of cigarette smoking in a workplace setting. Several practical issues have been identified and recommendations made for improving the use of systems of this kind in future studies.