The types of regular cigarette smokers: a latent class analysis.

The present study sought to refine cigarette smoking exposure by examining whether individuals with a history of regular cigarette smoking could be classified into meaningful subgroups based on their smoking habits, nicotine dependence, and quit attempts. Data were obtained from 3,025 male and female twins aged 22-59 years who participated in two longitudinal studies based on the Virginia Twin Registry. Latent class analysis was used to identify the number and nature of subgroups of smokers reporting similar smoking habits based on 18 characteristics. Estimates of prevalence for different classes of smoking were obtained along with expected frequencies of endorsements for each smoking behavior by class. Distributions of demographic characteristics, psychopathology, and personality were examined as external validators. The results demonstrated considerable heterogeneity and revealed eight classes of smokers who differed in their degree of nicotine dependence, cessation attempts, and ability to quit smoking. Smoking classes ranged from individuals who were all former smokers with low nicotine dependence who attempted to quit once and were successful, to individuals who were all current smokers with little desire to quit, to individuals with high nicotine dependence with multiple quit attempts, only a subset of which were successful. Estimates of prevalence for each class were 9%-20%. Our findings support the idea that regular cigarette smokers are highly heterogeneous and highlight the need for smoking exposure refinement in future studies. Acknowledging the complexity of cigarette smoking and classifying smokers into more specific subgroups based on their smoking behavior in future studies will enable more accurate evaluation of disease etiology and risk and could lead to more appropriate smoking cessation interventions.