Primary Aim: Characterize e-cig use patterns both acutely and over 2 years and relate them to patterns of CC use (including reduced CC use), nicotine dependence and related variables (e.g., withdrawal suppression), and attempts and success in quitting CC use. Investigators will use ecological momentary assessment (EMA) to obtain fine grained, real-time data on e-cig and CC use. These data will be used to test the hypotheses that increasing and higher levels of e-cig use, measured in real-time, will be negatively related to CC use, nicotine dependence, and CC withdrawal severity and positively related to CC quit attempts and CC cessation success.
Secondary Aim 1: Determine how the use of e-cigs is related to biomarkers of tobacco exposure and cancer risk, and to acute and chronic pulmonary health outcomes. Investigators will examine the relation between e-cig use and cancer biomarkers, exposure biomarkers, and pulmonary function.
Secondary Aim 2: Identify person factors, contextual variables, and patterns of behaviors and symp-toms that predict e-cig and CC use patterns and key outcomes (e.g., CC cessation, health-related outcomes), and identify variables that moderate relations between e-cig use and such outcomes. Investigators will attempt to identify contextual variables and person factors that predict increased e-cig use, decreased CC use (including cessation), reduced nicotine dependence, and significant changes in biomarkers and health outcomes. Further, investigators will identify variables that moderate such relations, revealing factors and events that make changes in e-cig and CC use, and associated outcomes, especially likely.
