NEW YORK -- When it comes to offering cash to get smokers to quit, more people go for the carrots than the stick - but the stick gets better results.

In a study released Wednesday, smokers with $150 of their own money at stake were far more likely to quit than smokers who didn't have to wager their money to get the cash rewards.

"A bit of a stick was much better than pure carrot," said the study's lead author, Dr. Scott Halpern of the University of Pennsylvania.

But here's the catch: Few people were willing to bet on themselves. Nearly everyone who was offered the rewards-only option, though, signed up for a stop smoking program.

As employers try to hold down health care costs, growing numbers of them have been using financial incentives to encourage workers to quit smoking or get healthier in other ways. But there's been relatively little research on what works best, said senior author Dr. Kevin Volpp.

The Penn researchers collaborated with CVS Health, the second largest U.S. drugstore operator, for the study. About 2,500 smokers took part - CVS employees, their relatives or friends.

THE INCENTIVES

Past research has found money is persuasive. Volpp and his colleagues tried to see what difference it made if employees stood not only to win money for quitting, but also to lose money.

About 1,000 smokers were offered the chance to win up to $800 if they could quit for six months. Participation was high - about 90 percent signed up.

Another 1,000 were asked to put $150 down as a deposit. It they quit for six months, they would get their $150 back plus $650 - a total of $800. Only 14 percent took that offer.

Another group of about 500 were offered no cash incentive, but did get the company's standard offering of counseling and nicotine replacement therapy.

THE OUTCOME

The few that put in their own money were a committed bunch. About half of them made it six months without a cigarette. That was a much better than the 17 percent of the rewards-only group that made it to the finish line.

But there were so many people in the rewards-only program that the actual number who quit in that group was much higher - 156, compared to 78.

Only 28 of the people offered no cash incentives quit - a measly 6 percent.

To get the largest number of people to stop, "it looks like the better bet might be for employers to supply pure reward," said Cliff Douglas, the American Cancer Society's vice president for tobacco control. He was not involved in the research.

The study was published in Thursday's New England Journal of Medicine.

TOO-HIGH STAKES

The study's authors say there's a compelling story in the success rate for the smokers who had money on the line. But they also say the $150 deposit apparently scared many away.

One participant, Camelia Escarcego of Rialto, California, said she is unemployed and wouldn't have been able to come up with the deposit. Her sister works for CVS and Escarcego ended up in the rewards-only group.

A 12-year smoker, Escarcego, 55, said the hundreds of dollars was enough motivation.

"That helped me to have a little bit of money in my pocket," she said.

Next month, CVS is to launch a quit smoking program for its 200,000 employees that will require a lower deposit of $50 and will award $700 to those who quit for a year.