The Fagerström Test for Nicotine Dependence (FTND; also called the Fagerström Test for Cigarette Dependence (Fagerstrom, 2012)) is perhaps the most widely used measure for studying genetic and epidemiological risk factors of nicotine dependence and likelihood of smoking cessation (Haddock et al., 1999; Heatherton et al., 1991). It focuses on core dependence criteria, including heavy use/tolerance and withdrawal (Baker et al., 2012), and remains an especially strong predictor of smoking cessation (Fagerstrom et al., 2012; Fidler et al., 2011). Its use across diverse studies with varying participant characteristics makes measurement invariance a vital psychometric issue to support the accuracy of analytic findings across a variety of studies.
