(The New York Times News Service) -- While nicotine replacement therapies make it easier for heavy smokers to quit the habit, the gum, lozenges, and patches do not appear to work long term to keep former smokers from lighting up again a few years later.

In a study published Monday in the journal Tobacco Control, researchers at the Harvard School of Public Health said they are surprised and disappointed by their results, which found that two-thirds of people resumed smoking within four years, even when nicotine therapies were used in conjunction with behavioral counseling.

The findings were based on nearly 800 Massachusetts smokers who had quit within the two years before joining the study, which began about a decade ago. That was after the state kicked off a Tobacco Cessation and Prevention Program, raising taxes on cigarettes, and initiating programs to help smokers quit and to keep others from starting.

"One of the cornerstones of this program was to enhance counseling and access to nicotine replacement therapies," said study coauthor Gregory Connolly, who helped launch the antismoking campaign at the state health department where he previously worked. "Yet what we found is that they have absolutely no effect."

The study found that one-third of recent quitters who used nicotine replacement therapies relapsed within two years after the study began, regardless of how long they used the therapy or whether they had counseling. That was the same relapse rate as among people who used no smoking-cessation aids.

After four years, an additional one-third resumed smoking in all the groups studied.

"It's very easy to get someone to quit smoking," said Connolly, who heads the public health school's Center for Global Tobacco Control, "but hard to get them to stay off cigarettes over a long period of time. The challenge is to come up with a better mousetrap."

The latest findings, he said, should give public health officials pause in terms of how much money they allocate toward smoking cessation programs.

Medicaid beneficiaries in Massachusetts can obtain FDA-approved smoking-cessation medications, including nicotine replacement therapies and drugs such as the antidepressant bupropion (Zyban) or varenicline (Chantix) for just $1 to $3 per month.

Another study published last week found that the $183 spent by the state for each Medicaid participant resulted in a $571 savings in hospital costs for smoking-related heart attacks and other cardiac events.

Lois Keithly, director of the Tobacco Cessation and Prevention Program at the Massachusetts Department of Public Health, said the Medicaid study, which looked at 75,000 smokers, is a more telling indicator of how well the state's smoking cessation programs are working.

"I think the Medicaid patients received more comprehensive interventions, including counseling that occurred in a medical setting," she said. "We know that nicotine replacement therapy works for some people, and we'd hate to say that, for an entire population, we shouldn't use it."

But the Medicaid study followed smokers for only a short time after they quit, while the Harvard study tracked them for several years, examining how most smokers quit in the real world, said Connolly. They often get sporadic counseling, if at all, and use nicotine therapies on their own, usually for less than the recommended minimum of six weeks, he said.

Earlier randomized controlled trials of nicotine patches, gum, and lozenges, usually funded by manufacturers of these products, tracked quitters for a year or less while providing them with frequent counseling to help them stop and use the products correctly.

Even with these ideal circumstances, "the efficacy of these products is real, but very small," said Jed Rose, director of the center for smoking cessation at Duke University Medical Center. "About 10 to 20 percent of smokers using nicotine therapies in these studies remain successful at quitting a year later, which is about double the success rate for those in the study who were given placebos."

While Rose agrees that better smoking-cessation aids are needed, he said he was not convinced by the conclusions of the Harvard study that nicotine aids are useless because of what he called a serious flaw in the design.

"Those who chose to use nicotine replacement were self-selected and might have felt they'd have a harder time quitting than those who chose not to use it, so it's a bit like comparing apples with oranges," he said.

Rose has been conducting research studies, some funded by cigarette-maker Philip Morris USA, to see whether smokers who wear nicotine patches two weeks before they quit, not recommended by the Food and Drug Administration, will cut back on cigarettes before taking their last puff.

Some do, he said, and usually have more success with patches after they quit, while those who do not cut back may benefit more from using Chantix or Zyban.

While nicotine replacement therapies make it easier for heavy smokers to quit the habit, the gum, lozenges, and patches don't appear to work long-term to keep ex-smokers from lighting up again a few years later. In a study published yesterday in the journal Tobacco Control, Harvard School of Public Health researchers said they are surprised and disappointed by their results, which found that two-thirds of people resumed smoking within four years.

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