Abstract
INTRODUCTION: Digital interventions present a scalable solution to overcome barriers to smoking cessation treatment, and changes in resting heart rate (HR) may offer a viable option for monitoring smoking status remotely. The goal of this study was to explore the acceptability of using smartphone cameras and activity trackers to measure heart rate for use in a smoking cessation intervention. METHODS: Participants (N=410), most of whom identified as female (75.8 %) with mean age 38.3 years (SD 11.4), were recruited via the Smoke Free app. They rated the perceived comfort, convenience, and likelihood of using smartphone cameras and wrist-worn devices for HR monitoring as an objective measure of smoking abstinence. Wilcoxon signed-rank tests and Kruskal-Wallis tests assessed differences in acceptability across device types and whether the participant owned an activity tracker/smartwatch or smartphone. RESULTS: Participants reported high levels of acceptability for both HR monitoring methods, with activity trackers/smartwatches rated more favorably in terms of comfort, convenience, and likelihood of use compared to smartphone cameras. Participants indicated a statistically significantly greater likelihood of using the activity tracker/smartwatch over the smartphone camera. Participants viewed the activity tracker/smartwatch as more acceptable than the smartphone camera (87.0% vs 50.0%). CONCLUSIONS: HR monitoring via smartphone cameras and wrist-worn devices was deemed acceptable among people interested in quitting smoking. Wrist-worn devices, in particular, were preferred, suggesting their potential as a scalable, user-friendly method for remotely monitoring smoking status. These findings support the need for further exploration and implementation of HR monitoring technology in smoking cessation research and interventions.