How much unsuccessful quitting activity is going on among adult smokers? Data from the International Tobacco Control Four Country cohort survey

AIMS: To document accurately the amount of quitting, length of quit attempts and prevalence of plans and serious thought about quitting among smokers. DESIGN: We used longitudinal data from 7 waves of the International Tobacco Control Policy Evaluation Four Country Survey (ITC-4). We considered point-prevalence data and cumulative prevalence over the 7 years of the study. We also derived annual estimates of quit activity from reports of quit attempts starting only within more recent time-frames, to control for biased recall. SETTING: Australia, Canada, the United Kingdom and the United States. PARTICIPANTS: A total of 21,613 smokers recruited across seven waves. MEASUREMENTS: Reported life-time quit attempts, annual quit attempts, length of attempts, time since last attempt started, frequency of aborted attempts, plans to quit and serious thought about quitting. FINDINGS: Around 40.1% (95% CI: 39.6-40.6) of smokers report attempts to quit in a given year and report an average of 2.1 attempts. Based on free recall, this translates to an average annual quit attempt rate of 0.82 attempts per smoker. Estimates derived only from the preceding month to adjust for recall bias indicate an annual rate of approximately one attempt per smoker. There is a high prevalence of quit-related activity, with more than a third of smokers reporting thoughts or actions related to quitting in a given month. More than half the surveyed smokers eventually succeeded in quitting for at least 1 month, and a majority of these for over 6 months. CONCLUSIONS: Smokers think a great deal about stopping and make many unsuccessful quit attempts. Many have been able to last for extended periods and yet they still relapsed. More attention needs to be focused on translating quit-related activity into long-term abstinence.