Understanding the role of numeracy and education in perceptions of e-cigarette harm and chemical exposure

Communicating about lower levels of harmful chemicals in e-cigarettes versus cigarettes may be important for informing adults who smoke about potential e-cigarette harm reduction benefits. Yet understanding and beliefs may depend on numeracy and education. This study explored how measures of numeracy and education relate to perceptions of chemical exposure and harm from e-cigarettes versus cigarettes among adults who smoke.

We analyzed data from a 2021 online survey with a nationally representative sample of 1018 US adults who currently smoke cigarettes, including measures of objective numeracy, subjective numeracy (preference for numbers vs. words), and education level (treated as independent variables), and measures of perceived harm and chemical content from e-cigarettes versus cigarettes (treated as outcomes). Weighted frequencies, chi-square tests, and logistic regression models examined associations between numeracy, education and the perception outcomes, adjusting for demographics and e-cigarette use.

Those with correct responses on the objective numeracy item had greater odds of believing that e-cigarettes contain fewer harmful chemicals than cigarettes, even after adjusting for education (adjusted odds ratio  = 1.8, 95% CI = 1.1 to 2.8), while subjective numeracy and education measures were not independently associated with this belief. None of the predictor variables (objective numeracy, subjective numeracy, education) were significantly associated with the broader belief that e-cigarettes are less harmful than cigarettes.

Our findings suggest that objective numeracy may play a significant role in beliefs about the level of harmful chemicals in e-cigarettes versus cigarettes.

Findings underscore the need to better understand how cognitive factors like numeracy shape tobacco decision-making, especially given the evolving science about e-cigarette safety and related communications.