Findings from a new study, conducted by a team of researchers at Dartmouth’s Geisel School of Medicine and collaborating institutions and published in the journal e-clinical Medicine, a member of the Lancet family of journals, show beneficial effects on functionally important respiratory symptoms when persons who smoke switch completely to e-cigarettes.
There is controversy about whether substituting noncombustible tobacco products for cigarettes can improve respiratory symptoms, such as wheezing and nighttime coughing, as this has been difficult to study.
“The problem is that a lot of people have tried e-cigarettes but most of them don’t completely substitute e-cigarettes for their cigarettes. Instead, they use both products,” says James Sargent, MD, a professor of pediatrics, of biomedical data science, and of community and family medicine at Geisel and lead author on the study.
“Persons who adopt e-cigarette use but also continue to smoke (dual use) continue to expose themselves to cigarette smoke,” he says. “Since they’re not completely eliminating exposure to the many thousands of chemicals found in tobacco smoke, they are likely to experience the same respiratory problems that smokers have,” he says. “We wanted to determine if completely or partially substituting e-cigarettes for cigarettes would be beneficial for persons concerned about respiratory symptoms.”
For their study, the investigators analyzed national survey data from the Population Assessment of Tobacco and Health Study—an observational cohort study funded by the FDA’s Center for Tobacco Products and NIH’s National Institute on Drug Abuse. The current study followed about 5,600 U.S. adults (over age 18) who smoked cigarettes at the beginning of the study (2014-2015) and did not have lung diseases such as COPD, chronic bronchitis, or emphysema. The findings apply broadly to people in the United States.
The study team created one-to-two-year observation periods (from 2014 to 2021), comparing functionally important respiratory symptoms (wheezing and nighttime coughing) in four groups—those who continued smoking cigarettes, those who adopted dual use, those who switched completely to e-cigarettes, and those who quit tobacco entirely.
“We wanted to determine if completely or partially substituting e-cigarettes for cigarettes would be beneficial for persons concerned about respiratory symptoms.”
- James Sargent, MD
“We were interested in knowing, for people that didn’t have symptoms, what was the risk of developing symptoms at follow-up across the four groups?” he explains. “And then, for people with symptoms, what was the likelihood their symptoms would go away across the four groups?”
The team found that only those who switched completely to e-cigarettes had a lower risk of developing respiratory symptoms and a higher likelihood that previous symptoms, if present, would go away. In both cases, complete switchers had about the same respiratory symptom risk as people who quit using tobacco entirely. On the other hand, there was no benefit for those who added e-cigarettes but did not discontinue smoking.
“We think our study’s findings provide important information for persons who use cigarettes who are willing to consider completely switching to a potentially lower-harm product,” says Sargent, who has developed a fact sheet that highlights risk scenarios based on the findings from the study.
Founded in 1797, the Geisel School of Medicine at Dartmouth strives to improve the lives of the communities it serves through excellence in learning, discovery, and healing. The Geisel School of Medicine is renowned for its leadership in medical education, healthcare policy and delivery science, biomedical research, global health, and in creating innovations that improve lives worldwide. As one of America’s leading medical schools, Dartmouth’s Geisel School of Medicine is committed to training new generations of diverse leaders who will help solve our most vexing challenges in healthcare.
