Electronic Nicotine Delivery Systems: Comparative Topography Assessments

Objectives: Due to rapidly emerging electronic nicotine delivery system (ENDS) technologies, increasing use in the US, and the unclear impact on users' health, investigating behavior associated with ad libitum ENDS use is an important research topic. ENDS use behavior is typically assessed either by direct observation or through smoking topography recording units; however, systematic comparisons between these methods are lacking. Therefore, we sought to compare 2 common methods to quantify ENDS topography. Methods: Current ENDS users (N = 18) used their own brand ENDS ad libitum in a clinical laboratory. We compared smoking topographybased recording units (desktop Clinical Research Support System; CReSS) and observational video-recordings with frame-by-frame (FxF) analysis methods to quantify ENDS topography. Results: Although CReSS analyses tended to estimate higher puff count and shorter average puff duration than FxF analyses, estimates of total puff duration were not different. Furthermore, both topography analysis methods showed significant associations with estimated nicotine intake. Conclusions: Neither the CReSS nor the FxF method is suited perfectly for analyzing ENDS topography. However, because FxF analysis is time-consuming and cumbersome, smoking topography-based recording unit methods may offer a more practical approach to measure ENDS topography; however, researchers must consider its limitations.