JMIR Publications

ABSTRACT

Background:

Tobacco use remains a leading preventable cause of morbidity and mortality. Digital health tools and wearable technologies offer scalable opportunities for behavioral self-monitoring. However, real-world evidence characterizing long-term tobacco use trajectories and associated physiological changes during wearable adoption are limited.

Objective:

To characterize longitudinal trajectories of self-reported tobacco use during the first 72 weeks of wearable adoption and examine associations between tobacco use and wearable-derived cardiopulmonary and sleep measures.

Methods:

We analyzed data from 12,678 new wearable members (18-79 yrs) who contributed up to 72 weeks of daily self-reported tobacco use and wearable-derived biometric data. Longitudinal trajectories of tobacco use were examined across prespecified 12-week quarters (Q1–Q6) using generalized linear mixed-effects models. Associations between tobacco use and nocturnal resting heart rate (RHR) and heart rate variability (HRV), respiratory rate (RR), and sleep duration were evaluated using linear mixed-effects models that accounted for within- and between-person variation and adjusted for demographic and temporal covariates.

Results:

Across 3,765,573 person-days, the estimated daily probability of tobacco use declined from 55.1% (95% CI: 53.8, 56.4) during Q1 to 27.2% (95% CI: 26.1, 28.3) during Q6, representing an absolute reduction of 27.9 percentage points (95% CI: -28.4, -27.4). Among tobacco users with end-of-follow-up data, 28.2% (1,404 of 4,975) reported no tobacco use during Q6. Greater logging engagement was associated with larger reductions in tobacco use; each 10 percentage point increase in engagement corresponded to a 0.92 percentage point greater decline from Q1 to Q6 (95% CI: -1.58, -0.26). Following tobacco-use days, RHR was 1.71 bpm higher (95% CI: 1.70, 1.73), HRV was 3.54 ms lower (95% CI: -3.59, -3.49), RR was 0.19 breaths/min higher (95% CI: 0.19, 0.20), and sleep duration was 9.78 minutes shorter (95% CI: −10.08, −9.49), relative to non-use days. Reductions in tobacco use over time were associated with directionally favorable changes in RHR, RR, and sleep duration (Ps≤.03).

Conclusions:

In this large-scale, real-world study of wearable device users, the probability of tobacco use declined over the first 72 weeks of wearable adoption. Among participants with end-of-follow-up data, more than one-quarter reported no tobacco use during Q6. Tobacco use was consistently associated with less favorable cardiopulmonary and sleep measures, while reductions in tobacco use over time co-occurred with directionally favorable changes in these measures. These findings provide large-scale, longitudinal evidence that sustained reductions in tobacco use co-occur with measurable favorable changes in physiological markers within a digital self-monitoring environment.