Measurement of Electronic Cigarette Frequency of Use among Smokers Participating in a Randomized Controlled Trial.

Introduction:
This text provides an analysis of the relationship between self-reported electronic cigarette (e-cig) use and actual use as measured by an automatic puff counter. The study aimed to determine the predictive value of self-reported e-cig use measures in predicting actual use (puffs) and to evaluate the value of the Penn State Electronic Cigarette Dependence Index (PSECDI) in measuring e-cig use.

Key Points:

* The study used data from a two-site randomized controlled trial evaluating the effects of e-cigs on toxicant exposure in smokers attempting to reduce their cigarette consumption.
* Participants randomized to an e-cig condition self-reported their e-cig frequency of use (times per day) on the PSECDI and kept daily diary records of the number of puffs per day from the e-cig automatic puff counter.
* a linear mixed-effects model was used to determine the predictive value of the times per day measure, and correlations were used to further investigate the relationship.
* The study found that self-reported e-cig use in times per day was a significant predictor of e-cig puffs per day (p < .01), with a Spearman correlation of r = .58.
* however, examination of individual participant responses revealed some potential difficulties in reporting and interpreting times per day due to the difference in use patterns between cigarettes and e-cigs.
* The study also found that quantifying e-cig use in patterns similar to cigarettes is problematic.
* The main message of the study is that self-reported measures of e-cig frequency of use are predictive of actual use, but there are challenges in quantifying e-cig use in patterns similar to cigarettes.

Main Message:
The study highlights the importance of developing valid and reliable measures of e-cig use, particularly in the context of regulatory decision-making. While self-reported measures of e-cig frequency of use are predictive of actual use, there are challenges in quantifying e-cig use in patterns similar to cigarettes. The study suggests that further research is needed to develop more precise and accurate measures of e-cig use that can inform regulatory decision-making.

Yingst J, Foulds J, Veldheer S, et al. Measurement of Electronic Cigarette Frequency of Use among Smokers Participating in a Randomized Controlled Trial. Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco. 2020;22(5):699-704. doi:10.1093/ntr/nty233