Relationship between the strength of craving as assessed by the Tobacco Craving Index and success of quitting smoking in Japanese smoking cessation therapy

Background We previously developed the Tobacco Craving Index (TCI) to assess craving of smokers. In the present study, we validated the relationship between the TCI grade over the 5 sessions of Japanese smoking cessation therapy (SCT) and success of quitting smoking among 889 Japanese patients. Methods The Japanese SCT consists of 5 sessions of SCT (first session and sessions 2, 4, 8 and 12 weeks later). In the TCI questionnaire, patients are asked to rate their strength of craving and frequency of craving, each on a four-point Likert scale. Patients are classified into one of four grades based on their responses (0, I, II, III, with III indicating severe craving). The TCI questionnaire was administered to each participant at each session of the SCT. This study included participants of Japanese SCT who answered the TCI at the first session of the SCT at five Japanese smoking cessation clinics. Patients who dropped out of the SCT from the second to the fifth sessions were considered to have failed smoking cessation. To elucidate how much the TCI grade predicts smoking status at the last session, we performed multivariate logistic regression analysis with adjustment for confounding factors. Results Participants who had higher TCI grade(III) in the 2^nd through 5^th sessions showed significantly lower probability for success of quitting smoking than those who had lower TCI grades(0 or I) (adjusted odds ratio: 2^nd session: 0.30, 3^rd session: 0.15, 4^th session: 0.06, 5^th session: 0.02). Conclusions We validated the usefulness of the TCI grade for assessing probability of quitting smoking by using a large number of smoking cessation settings.