Electronic cigarettes (e cigarettes) have been characterised as significantly less harmful than smoked tobacco by an increasing number of public health authorities. However, the proportion of American adults who perceive e cigarettes to be equally or more harmful than traditional cigarettes has increased over the last few years.

To quantify this, an analysis of the U.S. Population Assessment of Tobacco and Health (PATH) study was conducted to examine changes in how adults in the United States perceived the relative harm from wave 1 (September 2013 to December 2014) to wave 2 (October 2014 to October 2015).

According to the survey, 65 % of adult smokers perceived e cigarettes to be equally or more harmful than combustible cigarettes in 2015. This is a significant increase over the 54 % who reported the same perception in 2013.

The proportion of adult current and everyday smokers who believed e cigarettes were just as, or more, harmful than smoking increased substantially from 43 % in 2013 to 57 % in 2015 (+14 %). This is despite the growing independent scientific evidence base reporting the relative safety of e cigarettes compared to combustible tobacco during that time.

Misperceptions of the relative harm of e cigarettes compared with conventional cigarettes need to be urgently addressed, particularly among smokers who may benefit from switching to e cigarettes. Of the smokers that switched to e cigarettes between 2013 (wave 1) and 2015 (wave 2), 95 % correctly identified e cigarettes as being less harmful than conventional cigarettes.

If nothing is done to change the misperceptions of the relative harm of e cigarettes compared with conventional cigarettes, based on current trends, it is estimated that in five years, 70 % of the U.S. smokers will perceive e cigarettes as harmful as, or more harmful than, cigarettes.