Background: Few studies have investigated the association between age at smoking initiation and Fagerström test for nicotine dependence (FTND) in adulthood. The goal of this study was to develop the Korean version of FTND (FTND-K) and to examine the relationship between age at smoking initiation and nicotine dependence.
Methods: This investigation used data from 268 current smokers who visited the Center for Cancer Prevention and Early Detection in the National Cancer Center, Korea. The internal consistency of the FTND-K was assessed by Cronbach's coefficient alpha. Pearson's correlation coefficients were used to assess the relationships between the FTND-K sum scores and urinary cotinine levels. One-way analysis of variance (ANOVA) and t-tests were used to assess differences in the FTND-K sum score between groups. Factor associated with nicotine dependence were identified through stepwise multiple logistic regression analysis.
Results: The standardized Cronbach's alpha of FTND-K was 0.72. A significant positive correlation was seen between the FTND-K sum score and urinary cotinine level (correlation coefficient = 0.49, P < 0.05). Age at smoking initiation had a significant association with the FTND-K sum score in univariate analysis. In multivariate analysis, nicotine dependence was higher in smokers that started smoking cigarettes at 19 years or earlier than in those that started at 25 years or later (OR = 11.25, 95% CIs, 1.46-97.10).
Conclusions: The FTND-K is a valid assessment tool of nicotine dependence with acceptable levels of internal consistency and close correlation to urinary cotinine level. The finding that those who initiate smoking at an early age tend to be more nicotine dependent underscores and reinforces the public health significance of delaying smoking onset.