We operationally defined tobacco use (TOB) as someone having smoked a total of 100 cigarettes over lifetime and having a >0 score on the Fagerström Test for Nicotine Dependence (FTND; Heatherton et al., 1991), and no tobacco use was defined as someone with <100 lifetime cigarettes with a zero on FTND. Because FTND was not administered during the early phase of COGA data collection, a separate yes/no question from the SSAGA (“Have you ever smoked cigarettes daily for a month or more?”) was substituted to define tobacco use for those without the FTND data.
