Effect of nicotine chewing gum in combination with group counseling on the cessation of smoking.
We studied the effectiveness of chewing gum containing nicotine, in combination with group counseling, for subjects who were attempting to stop smoking. We used the Horn-Russell scale, based on a smoking questionnaire, to measure dependence on cigarettes; 173 smokers were grouped as highly dependent on nicotine or as having medium to low degrees of dependence. In a randomized double-blind study, the 60 highly dependent smokers were given gum containing 4 mg of nicotine (n = 27) or 2 mg of nicotine (n = 33), and the 113 smokers with medium or low dependence were given gum containing 2 mg of nicotine (n = 60) or a placebo gum (n = 53). All smokers took part in group counseling. In the highly dependent group, abstinence from cigarettes was chemically verified after six weeks, one year, and two years; 81.5 percent, 44.4 percent, and 33.3 percent of the subjects given gum containing 4 mg of nicotine were abstinent after those follow-up periods; the rates of abstinence were 54.5 percent, 12.1 percent, and 6.1 percent, respectively, for the subjects given gum containing 2 mg of nicotine. In the group with medium or low dependence, the rates of abstinence after the same periods were 73.3 percent, 38.3 percent, and 28.3 percent for the subjects given gum containing 2 mg of nicotine and 41.5 percent, 22.6 percent, and 9.4 percent for those given placebo gum. The differences in outcomes were significant at the 5 percent level for all comparisons, with the exception of the 2-mg nicotine gum versus the placebo gum at one year. This study indicates that the effectiveness of nicotine gum is not due to a placebo effect and that it is related to dose. The use of nicotine gum in appropriate doses should be helpful to persons who are attempting to stop smoking.