Table 1.

Definitions for Initial Baseline Probabilities in the Markov Models

Tobacco Use States	Definition
Non-current use	Individuals met criteria (1) or (2): 1) never use, which included never used a tobacco product OR smoked no tobacco products in their lifetime (including cigarettes, cigars, pipes, little cigars, e-cigarettes, and hookah) 2) non-current use, which included tried a tobacco or nicotine product only once OR never used a tobacco or nicotine product monthly AND had used neither cigarettes nor e-cigarettes in the past 30 days.
Cigarette use	Individuals used cigarettes during the past 30 days at the current wave.
Dual cigarette and e-cigarette use	Individuals used cigarettes and e-cigarettes during past 30 days at the current wave.
E-cigarette use	Individuals used e-cigarettes during the past 30 days at current wave.
Former use	Individuals reported no past 30-day use of either product at the current wave but reported past 30-day use of either product at a prior wave.