# Dual use of combustible and electronic cigarettes: A fine-grained naturalistic cohort study to investigate dynamic use patterns and trajectories that lead to smoking cessation

> **NIH NIH R01** · MEDICAL UNIVERSITY OF SOUTH CAROLINA · 2024 · $645,039

## Abstract

As the tobacco product landscape continues to shift, there has been a dramatic increase in poly-tobacco use,
particularly the dual use of combustible and electronic (e-)cigarettes. The health implications of dual use are
unclear, as are the treatment and policy decisions as to how to best manage it. On one hand, dual use has the
potential to decrease both individual and population harm, insofar that toxicant exposure is lowered and eventual
cessation of combustible cigarettes becomes possible, as growing evidence suggests. However, harm reduction
is maximized only when dual users transition completely away from combustible cigarette smoking, and when
that transition is sustained. Indeed, the potential benefits of e-cigarettes are unrealized if dual users fail to quit
smoking. Thus, dual use has the potential to reduce or perpetuate harm. The critical difference between these
two outcomes is how these harm reducing/promoting tobacco products are used interchangeably; i.e., patterns
and trajectories over time. Unfortunately, the natural course of dual use, particularly in comparison to exclusive
smoking or vaping, is unclear. Cohort studies of dual use, often derived as secondary analyses from national
surveillance projects with yearly assessments, suggest that, for some, dual use can be either transient or
prolonged. Almost all of these studies lack detail on anything beyond use status (using vs. not), and particularly
lack detail on daily patterns of use over time. A focused and more granular assessment of dual use patterns is
needed to understand who these individuals really are, and how their smoking and vaping behaviors do and do
not change over time. Within a nationally based cohort study of dual users (n=396), and exclusive users of both
combustible (n=198) and e-cigarettes (n=198), natural use histories will be assessed through a combination of
a) detailed daily diaries over 3 months, b) serial bursts of nightly diaries that coincide with c) episodic monthly
surveys over a 1-year follow-up, and d) biological verification of combustible cigarette smoking. Study aims are
to 1) describe, and 2) compare the consistency of use behaviors over time, within and across cohorts. As a third
aim, using a within-subjects approach, we aim to assess the defining day-to-day patterns of dual use that best
predict subsequent abstinence from combustible cigarette smoking. The proposed project is the largest and
longest study of dual users (vs. exclusive users) ever conducted with a priori design considerations to more fully
understand the complex interplay between these two products, one of which is the root cause of significant
cancer incidence and mortality, and the other is a controversial harm reduction option with fast growing
population appeal. Building upon a successful program of cancer prevention research using naturalistic research
designs, remote methods, and team science, the proposed study expands our foundational knowledge regarding
tobacco use ...

## Key facts

- **NIH application ID:** 10999155
- **Project number:** 1R01DA061566-01
- **Recipient organization:** MEDICAL UNIVERSITY OF SOUTH CAROLINA
- **Principal Investigator:** Matthew J Carpenter
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $645,039
- **Award type:** 1
- **Project period:** 2024-07-01 → 2029-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10999155

## Citation

> US National Institutes of Health, RePORTER application 10999155, Dual use of combustible and electronic cigarettes: A fine-grained naturalistic cohort study to investigate dynamic use patterns and trajectories that lead to smoking cessation (1R01DA061566-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10999155. Licensed CC0.

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