The New England Journal of Medicine just published a smoking cessation study that measured how financial rewards and penalties affect quit rates. While the study generated moderate media interest (examples here and here), the big story was buried deep in a supplemental table: the quit rate was always abysmal.
Investigators from the University of Pennsylvania, led by Dr. Scott Halperin, recruited 4,017 CVS Caremark employees, relatives and friends who smoke and randomized them to one of five interventions. The control group received cessation pamphlets from the American Cancer Society; CVS employees were also provided with free behavior therapy and pharmaceutical nicotine. In addition to pamphlets, the other four groups had one of four interventions: they received up to $800 rewards for quitting as (1) individuals or (2) in small-group settings, or they paid deposits of $150 that were refunded and coupled with rewards upon quitting, either as (3) individuals or (4) in small groups.
Halperin et al. analyzed quit rates at six months after enrollment, concluding: “Reward-based programs were much more commonly accepted than deposit-based programs, leading to higher rates of sustained abstinence from smoking. Group-oriented incentive programs were no more effective than individual-oriented programs.” More importantly, they also reported the results after what is normally considered the gold standard for follow-up -- one year. Here is a summary of the findings:
|Quit-Smoking Rates From the CVS Caremark Study at One Year|
|Intervention||Number of Participants Who Quit / Total||Success Rate|
|Usual Care||16 / 468||3.4%|
|Individual Reward||37 / 498||7.5%|
|Group Reward||45 / 519||8.7%|
|Individual Deposit||21 / 582||3.5%|
|Group Deposit||29 / 471||6.2%|
|All Participants||148 / 2,538||5.8%|
All told, only six of every 100 smokers quit at one year. This represents about a 50% relapse rate from the six-month results that Halperin and colleagues used for their analyses. That rate applies only to the 2,538 smokers who did not drop out before the study started. Considering all 4,017 eligible smokers, the quit rate was 3.7%, the same or even lower than the quit rate in the general population.
Halperin and his colleagues deserve credit for trying to use economic incentives to change smoking cessation rates. Unfortunately, their study proves once again that most smokers are unwilling or unable to quit.