Debunking myths about self-quitting (1989): a classic study.
The study was conducted because a prior paper, based on a small number of people (161) had suggested that people who quit on their own are generally quite successful (more so than people who go for professional treatment) and that heavy smokers were just as likely to quit successfully on their own as light smokers. The researchers decided to pool together the data from 10 larger studies of “self-quitters” (smokers making a quit attempt without receiving any formal treatment), in order to get to the truth on these questions.
They picked 10 “prospective” self-quitting studies that followed people up for at least 6 months (most were at least 12 months) and that provided biochemical or other verification of people’s claim to have quit. Using prospective studies avoids the self-selection and recall biases you get when you simply recruit a group of people and ask them what it was like for them when they tried to quit. The 10 studies had taken place all over the country and included over 5,000 smokers and so this was thought more likely to provide results that would be generalizable to the population of smokers trying to quit on their own in the United States. One other good aspect of this study was that it included different measures of quitting, and assessed outcomes at numerous time points, enabling an analysis of both continuous “not a puff” quitting after a single attempt, as well as long term “point prevalence” abstinence, that may be the result of repeated quits and relapses over time.
The median “not a puff” continuous quit rate a year later was 4.2% and the median “point prevalence, not smoked in the past week” quit rate at 12 months was 14%. Those who tried to quit completely on their own, and those who had a manual to help them had similar quit rates. The study also found that heavy smokers (those smoking over a pack a day) were less than half as likely to quit for a year as less heavy smokers (a pack per day or less).
The study examined whether the number of previous quit attempts predicted the likelihood of successful quitting on this quit attempt. It found that although those who had never tried to quit before had slightly lower quit rates, there was no significant relationship between the number of prior quit attempts and success this time. A substantial proportion (24%) of those who had quit at 6 months had relapsed back to smoking by 12 months.
So this study was successful in debunking a number of myths about quitting smoking that were prevalent at the time. It showed that smokers who simply try to quit on their own with no assistance, do not (as had been claimed, and is still sometimes claimed) have surprisingly high quit rate. In this study the one year quit rates were in the range 4-14% depending on your definition. It also showed that quit rates vary by simple measures of baseline ‘dependence,” with heavier smokers having lower quit rates than less heavy smokers. It also found that the number of previous quit attempts has relatively little influence on a smoker’s chances of successfully quitting on the next quit attempt. Finally the study showed that a substantial proportion of smokers (around a quarter) who quit for 6 months, are likely to relapse in the next 6 months. One of the main conclusions of the study was that, “quitting smoking (by oneself or with the aid of a program) should be viewed as a process and not as a discrete event.” Wise words.
20 years later, even although the core findings from this study have been replicated many times, we still hear some of the myths about quitting smoking being repeated. The classic mistake (which resulted in the small study that prompted this one) is to try to figure out how people quit by asking a handful of successful self-quitters what it was like for them. Don’t be surprised if they tell you that the last time (i.e. the successful one, so far) wasn’t too hard. But that would be missing out on data from the other 95% of quit attempts that were not successful.
Cohen S, Lichtenstein E, Prochaska JO, Rossi JS, Gritz ER, Carr CR, Orleans CT, Schoenbach VJ, Biener L, Abrams D, et al. Debunking myths about self-quitting. Evidence from 10 prospective studies of persons who attempt to quit smoking by themselves. Am Psychol. 1989 Nov;44(11):1355-65.