Objective: To identify predictors of smoking cessation success or failure with and without transdermal nicotine patch treatment.
Design: Two independent randomized, double-blind, placebo-controlled studies using the nicotine patch assessing outcome at the end of treatment and at 6-month follow-up; each study used a different mode of adjuvant counseling.
Patients: Subjects were daily smokers (> or = 15 cigarettes per day), aged 21 to 65 years with expired air carbon monoxide levels of at least 10 ppm, and motivated to quit. Eighty-eight subjects participated in study 1, and 112 subjects participated in study 2.
Intervention: Study 1 consisted of 8 weeks of 22-mg nicotine patch therapy with intensive group counseling. Study 2 consisted of 4 weeks of 22-mg nicotine patch therapy and 2 weeks of 11-mg nicotine patch therapy with brief individual counseling.
Main outcome measures: The prediction of smoking cessation (at end of treatment and after 6 months) based on pretreatment and intratreatment measures in smokers using active or placebo nicotine patches.
Results: Pretreatment markers, such as the Fagerstrom Tolerance Questionnaire score, number of cigarettes smoked per day, years smoked, expired air carbon monoxide level, or baseline blood nicotine and cotinine levels, showed no consistent relationship with successful smoking cessation across both studies. Of the intratreatment markers examined, withdrawal severity and nicotine replacement levels also were not consistently predictive of cessation success. However, any smoking during the second week of treatment was a consistent and powerful predictor of failure at the end of treatment and after 6 months. Among active nicotine patch patients who smoked at all during week 2 after quitting, 83% and 97% (studies 1 and 2, respectively) were smoking at 6-month follow-up. Conversely, abstinence during the second week of treatment predicted successful smoking cessation. Among active nicotine patch patients who were totally abstinent during week 2 after quitting, 46% and 41% (studies 1 and 2, respectively) were abstinent at 6-month follow-up. Of all nicotine patch patients in both studies who were smoking at 6-month follow-up, 74% began smoking during week 1 or 2. Among all placebo patch patients who were smoking at 6-month follow-up, 86% began smoking during week 1 or 2.
Conclusions: Smoking status (abstinent or smoking) during the first 2 weeks of nicotine patch therapy, particularly week 2, was highly correlated with clinical outcome and can serve as a powerful predictor of smoking cessation. Early smoking behavior also predicted outcome among placebo patch users. Traditional measures of dependence are not consistently predictive of cessation success. Clinicians are advised to emphasize the importance of total abstinence after a quit attempt and to follow-up with patients within the first 2 weeks of quitting; smoking during this critical time should be assessed and treatment may be altered as appropriate.