In the U.S. more than 16 million people with smoking–related illnesses continue to use cigarettes. According to a new study in the American Journal of Preventive Medicine, current and former smokers who suffer from disease are more likely to have reported using an e–cigarette, meaning these patients may see e–cigarettes as safer or less harmful than combustible cigarettes and a way to reduce the risks posed by traditional smoking.

Use of electronic cigarettes has significantly increased in recent years. In 2010, only 2% of American adults had ever used an e–cigarette, but by 2014, that number had jumped to 12.6%. While most people see e–cigarettes as a safer alternative to traditional combustible smoking, many questions remain unanswered about their effects.

Using data from the 2014 and 2015 National Health Interview Survey (NHIS), investigators found that current smokers who also suffered from one or more medical conditions were more likely to have used an e–cigarette than "healthy" smokers (those without any comorbidities). The study included 36,697 adults in 2014 and 33,672 adults in 2015.

"This large sample provides the first national estimates of the prevalence of e–cigarette use among U.S. adults with medical comorbidities," explained lead investigator Gina R. Kruse, MD, MPH, Assistant Professor of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston. "Current smokers with medical comorbidities use e–cigarettes at higher rates than smokers without medical comorbidities. Very few never smokers with medical comorbidities have ever used e–cigarettes, except in the youngest age groups."

The data revealed that not only are smokers with comorbidities more likely to use e–cigarettes, but that e–cigarette use continues to rise, especially among present smokers (47.6% in 2014 vs. 53.5% in 2015). Current smokers with asthma, COPD, or cardiovascular disease reported e–cigarette use more often than other groups. Among former smokers, individuals with COPD reported more e–cigarette use compared to those without chronic disease; however, former smokers with cancer had lower odds of current e–cigarette use.

"Smokers with asthma, COPD, or cardiovascular disease probably use e–cigarettes for the same reasons as other adults: to quit cigarettes, reduce cigarette consumption, or reduce the harms from smoking," said Dr. Kruse. "Smokers with these chronic diseases may feel an urgent need to quit or reduce combustible cigarette use and may be willing to try new products. Conversely, among adults with cancer, the low prevalence of e–cigarette use may be because even a reduced harm product is seen as too late to help them."

While health care providers and researchers are still trying to fully understand possible health risks associated with e–cigarettes, there is a growing consensus that their use can possibly help people quit combustible cigarettes and curb tobacco–related risks. Switching to e–cigarettes might have greater positive impact for current smokers with health problems.

"E–cigarette use by current and former smokers with medical comorbidities is substantial, especially among individuals with chronic lung or cardiovascular disease. Clinicians should routinely ask these patients about e–cigarette use, assessing potential risks and benefits in terms of reducing or quitting combustible cigarette use. Clinicians should also actively consider all pathways to help their patients quit combustible cigarettes and recommend evidence–based treatments," commented Dr. Kruse.