If at first you don't succeed, when should you try again? A prospective study of failed quit attempts and subsequent...

To assess the association between likelihood of success of smoking cessation attempts and time since most recent attempt.

Prospective study of 823 smokers who reported a failed quit attempt in the last 12 months at baseline and ≥1 quit attempt over 6-month follow-up. The input variable was time in months between the end (and in an exploratory analysis, the start) of the most recent failed quit attempt reported retrospectively at baseline and start of the first attempt made during the 6-month follow-up period. The outcome variable was success in the latter quit attempt.

Success rates for failed quitters who waited <3, 3-6, and 6-12 months between their failed quit attempt ending and making a subsequent quit attempt were 13.8%, 17.5%, and 19.0% respectively. After adjustment for covariates, the odds of cessation relative to those who made a subsequent quit attempt within 3 months were 1.42 (95%CI 0.79-2.55) and 1.52 (95%CI 0.81-2.86) for those who waited 3-6 and 6-12 months respectively before trying again. Bayes factors indicated the data were insensitive. The exploratory analysis showed the odds of cessation were 1.55 (95%CI 0.78-3.08), 1.92 (95%CI 0.94-3.92), and 2.47 (95%CI 1.04-5.83) greater for those with an interval of 3-6, 6-12, and 12-18 months respectively than those who tried again within 3 months.

While pre-planned analyses were inconclusive, exploratory analysis of retrospective reports of quit attempts and success suggested the likelihood of success of quit attempts may be positively associated with number of months since beginning a prior quit attempt. However, only the longest inter-quit interval examined (12-18 months) was associated with significantly greater odds of quit success relative to a <3 month interval in fully adjusted models; all other comparisons were inconclusive.