Objective: To assess differences in demographic and smoking characteristics between smokers who have and have not used nicotine replacement therapy (NRT).
Design: Mail survey of US smokers from a national research panel.
Participants: Smokers 18 years and over who returned a survey on smoking (n = 9630). The sample was weighted to match the US smoker population on age and sex.
Main outcome measures: Compared smokers who had/had not used NRT in a quit attempt (ever NRT use or over the counter (OTC) NRT use) on: demographic characteristics, nicotine dependence, history of craving and withdrawal, expected difficulty quitting, and self reported history of smoking related medical illness and psychopathology.
Results: NRT users (both ever-users and OTC users) were more likely to be older, male, and better educated. They were also heavier smokers, had experienced more craving and withdrawal upon quitting, and scored higher on measures of dependence. These differences were evident among light smokers, and remained even when smoking rate and time to first cigarette were controlled.
Conclusion: Smokers who elect to use NRT differ from non-NRT users in ways that predispose them to failure in cessation. Controlling for smoking rate and time to first cigarette does not eliminate these differences, even among light smokers. These differences must be considered when comparing the effectiveness of NRT among samples of smokers who self select their treatment and are likely to bias such outcome comparisons.