Background: The reasons for relapse to smoking are not fully understood but several factors are of importance. Addiction to nicotine seems to play a prominent role but there are several other contributing factors.
Methods: To determine predictors of outcome in smoking cessation, we performed univariate and multivariate analyses in a large smoking cessation trial comprising 289 subjects. Weight gain and withdrawal symptoms were analyzed separately as predictors. To determine self-perceived reasons for relapse we created a questionnaire, which was answered by 132 relapsers.
Results: Previous attempts to quit smoking and a low saliva cotinine concentration were significantly associated with abstinence in the nicotine-treated group. A trend toward higher abstinence rates was found among males and among subjects with a low nicotine dependency score. Logistic regression analysis showed higher success rates in subjects with the largest weight gain during the first weeks of quitting in contrast to higher relapse rates in subjects who had the greatest weight gain after 3 months. A high score on withdrawal symptoms was not predictive of relapse. Subjects with "slips" had a markedly increased relapse rate. Craving for cigarettes was the most often self-reported (48%) reason for relapse.
Conclusions: The relation between weight gain, withdrawal scoring, and outcome seems rather complex. Craving for cigarettes was the most reported reason for relapse.