Assessment of a Personal Interactive Carbon Monoxide Breath Sensor in People Who Smoke Cigarettes: Single-Arm Cohort Study

Abstract

Background: Tobacco use is the leading cause of preventable morbidity and mortality. Existing evidence-based treatments are underutilized and have seen little recent innovation. The success of personal biofeedback interventions in other disease states portends a similar opportunity in smoking cessation. The Pivot Breath Sensor is a personal interactive FDA-cleared (over-the-counter) device that measures carbon monoxide (CO) in exhaled breath, enabling users to link their smoking behavior and CO values, and track their progress in reducing or quitting smoking.

Objective: The objective of this study is to assess the Pivot Breath Sensor in people who smoke cigarettes, evaluating changes in attitudes toward quitting smoking, changes in smoking behavior, and use experience.

Methods: US adults (18-80 years of age, ≥10 cigarettes per day [CPD]) were recruited online for this remote 12-week study. Participants completed a screening call, informed consent, and baseline questionnaire, and then were mailed their sensor. Participants were asked to submit 4 or more breath samples per day and complete questionnaires at 1-4, 8, and 12 weeks. Outcomes included attitudes toward quitting smoking (Stage of Change, success to quit, and perceived difficulty of quitting), smoking behavior (quit attempts, CPD reduction, and 7-, 30-day point prevalence abstinence [PPA]), and use experience (impact and learning).

Results: Participants comprised 234 smokers, mean age 39.9 (SD 11.3) years, 52.6% (123/234) female, mean CPD 20.3 (SD 8.0). The 4- and 12-week questionnaires were completed by 92.3% (216/234) and 91.9% (215/234) of participants, respectively. Concerning attitude outcomes, at baseline, 15.4% (36/234) were seriously thinking of quitting in the next 30 days, increasing to 38.9% (84/216) at 4 weeks and 47.9% (103/215) at 12 weeks (both P<.001). At 12 weeks, motivation to quit was increased in 39.1% (84/215), unchanged in 54.9% (118/215), and decreased in 6.0% (13/215; P<.001). Additional attitudes toward quitting improved from baseline to 12 weeks: success to quit 3.3 versus 5.0 (P<.001) and difficulty of quitting 2.8 versus 4.3 (P<.001). Regarding smoking behavior, at 4 weeks, 28.2% (66/234) had made 1 or more quit attempts (≥1 day of abstinence), increasing to 48.3% (113/234) at 12 weeks. At 4 weeks, 23.1% (54/234) had reduced CPD by 50% or more, increasing to 38.5% (90/234) at 12 weeks. At 12 weeks, CPD decreased by 41.1% from baseline (P<.001), and 7- and 30-day PPA were 12.0% (28/234) and 6.0% (14/234), respectively. Concerning use experience, 75.3% (171/227) reported the sensor increased their motivation to quit. More than 90% (>196/214) indicated the sensor taught them about their CO levels and smoking behavior, and 73.1% (166/227) reported that seeing their CO values made them want to quit smoking.

Conclusions: Use of the Pivot Breath Sensor resulted in a significant increase in motivation to quit, a reduction in CPD, and favorable quit attempt rates. These outcomes confer increased likelihood of quitting smoking. Accordingly, the results support a role for biofeedback via personal CO breath sampling in smoking cessation.

Trial registration: ClinicalTrials.gov NCT04133064; https://ichgcp.net/clinical-trials-registry/NCT04133064.

Keywords: biofeedback; breath sensor; carbon monoxide; digital health; digital sensor; smartphone; smoking cessation.

Conflict of interest statement

Conflicts of Interest: JM, CF, KW, and DB are employees of Carrot Inc, the developer of the Pivot Breath Sensor used in this study. They receive salary and stock options from Carrot Inc. DU is the President and CEO of Carrot Inc and an investor in the company.

©Jennifer D Marler, Craig A Fujii, Kristine S Wong, Joseph A Galanko, Daniel J Balbierz, David S Utley. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 02.10.2020.

Figures

Figure 1

Pivot Breath Sensor and color coding of carbon monoxide values.

Figure 2

Study participant flow: Consolidated Standards of Reporting Trials (CONSORT) diagram.

Figure 3

Attitudes towards quitting smoking, ratings (scale 1-10) at baseline vs. 12 weeks. Estimate of means and standard errors based on linear mixed model. Readiness to quit smoking (RTQ), Difficulty to quit smoking (DTQ), Success to quit smoking (STQ).

Figure 4

Participant goals at baseline and 12 weeks.

Figure 5

Percent change in cigarettes per day (CPD) over time. Estimate of means and standard errors based on linear mixed model.

Figure 6

Participant Feedback: Effect of breath sensor on motivation to quit smoking (week 1).

Figure 7

Participant Feedback: Effect of breath sensor on number of cigarettes smoked per day (week 1).

Figure 8

Participant Feedback: Impact of carbon monoxide values on thoughts about quitting (week 1).

Figure 9

Participant Feedback: Thoughts on the Pivot Breath Sensor (week 2).

Figure 10

Participant Feedback: Pivot Breath Sensor’s ability to help someone quit smoking (week 2).

Figure 11

Participant Feedback: Has the breath sensor taught you about your carbon monoxide (CO) levels? (week 3).

Figure 12

Participant Feedback: Has the breath sensor taught you about your smoking behavior? (week 3).

Figure 13

Participant Feedback: Understanding of CO levels and trends as they relate to smoking behavior (week 4).

Figure 14

Breath sensor use.

Figure 15

Participant Feedback: Reasons for not using the breath sensor (week 12).