A systematic review of 17 studies involving nearly 6,300 participants showed that despite incentives ranging from lottery tickets to cash payments, quit smoking contests did not help people to kick the habit.
In one study, participants were encouraged to toss their cigarettes down the toilet and rewarded with one lottery ticket per day. Another offered payments of 10 dollars per month and participation in a monthly worksite lottery.
Yet another offered cash prizes ranging from 100 dollars to 250 dollars, along with certificates of recognition.
"In my view, none of them was effective," said review co-author Kate Cahill at the University of Oxford.
"One of our main conclusions was that if incentives work at all, they only work while they're in place; if you revisit those quitters 12 or 24 months down the line, they [smokers offered incentives] were generally no more successful" than counterparts not offered incentives," she added.
One-year cessation rates for participants in one study were 22 percent - more than double that of those not offered incentives.
However, by the one-year evaluation, the quit rate for participants was much closer to that of non-participants.
In addition, the difference between participants and the group not offered incentives "had become non-significant at the two-year follow up," the reviewers found.
"An effective incentive should be large enough to attract smokers motivated to try and quit, but not so attractive that the desire to win outweighs the seriousness of the quit attempt," said the reviewers.
Michael Fiore, director of the University of Wisconsin Center for Tobacco Research and Interventions said that the cessation contests in the review clearly did not offer a big bang for the buck.
However, he added, "Maybe some of these programs have collateral benefit, in that they encourage people - who may not have thought about quitting - to quit."
The review appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration.