Do you remember learning about the asymptote in high school geometry? It’s that funny curve that gets closer and closer to a line through infinity, but never actually touches it. We say the curve “asymptotically” approaches zero.

Smokers are a little like this. As the rate of smoking asymptotically approaches zero, we are left with a population that is more and more “hardened” in its smoking habit. Around 70% of current smokers have no interest in quitting. So the smoking behaviors of the ~14% of people still smoking now are, person-for-person, harder to change than they were in the much larger fraction of the population who smoked five years ago. That is, as the population of smokers shrinks, it becomes ever harder to get the remaining smokers to stop. So most studies of smoking interventions like drugs, nicotine replacement, or therapy, ignore people who express little interest in quitting. Coordinators for most studies instead recruit people whose “readiness to change” is higher:

But a new study (paywall) takes this population of hardened smokers head-on with, of all things, a video game. Investigators recruited 433 smokers who reported they were not ready to quit. They randomized the smokers to get usual care with nicotine replacement therapy lozenges, or to get access to nicotine replacement therapy plus “Take a Break,” a 3-week mobile “game experience” that included 5 behavioral components: motivational messaging, challenge quizzes, brief abstinence goal setting, mobile health apps for cravings management (three “relaxation” apps were offered), and reward points for participation (in the form of gift cards).

To determine if the game had an effect, they looked at the time to their first quit attempt and tested carbon monoxide levels at 6 months to verify any claims of smoking cessation (smoking increases carbon monoxide levels in your blood, which, blech).

Apps are tricky because people tend to lose interest pretty quickly. Only about half of the game participants got through 100% of their daily challenge quizzes in the first week in the study. Roughly three-fourths set a brief abstinence goal of 1-2 days away from cigarettes, and 75% used the apps to manage their nicotine cravings. The game-treated participants set a sooner “time to quit,” and at six months, 18% (28 of 160) of game participants versus 10% (17 of 171) of nicotine replacement-only participants had carbon monoxide level–verified smoking cessation, roughly a doubling of the likelihood of smoking cessation once the fancy statistical analysis was done.

Those numbers look kind of sad, but remember that we’re talking about a very difficult population in the study, people who had expressed almost no interest in changing at the study’s onset. Through that lens, this is really a remarkable outcome, albeit in a small study. The best-performing clinics in the U.S. only get around 15% of their smokers to quit in any given year, and that is in a group of patients whose readiness to quit is undoubtedly higher than the population of this study.

As far as I can tell, the app isn’t available commercially yet. When “Take A Break” or its descendant products are available, though, we should think hard about using them. Smoking is still one of the leading causes of death, disability, and medical expenditures, so even a hefty price tag for such a product would be worth doubling the number of smokers who successfully quit in any six-month period.

As we’ve talked about before, we get pitched a lot of apps at KBGH. Do you have any positive experiences with skill-building or behavior change apps? If so, please share!

As the Medical Director of the Kansas Business Group on Health, I’m sometimes asked to weigh in on hot topics that might affect employers or employees. This is a reprint of a blog post from KBGH.