This observation held up among both heavy and light smokers, regardless of whether or not nicotine replacement therapy was accompanied by professional cessation counselling.

“Even though other well-controlled studies have shown that nicotine replacement therapy can be effective, our study looked at real-world use over the long-term,” said study lead author Hillel Alpert, a research scientist with the Harvard School of Public Health’s Center for Global Tobacco Control in Boston. “And in the real world, cigarettes are simply a very powerful addiction. And NRT is apparently not an effective replacement for that addiction.”

Alpert and his colleagues published their findings in the Jan. 9 online edition of Tobacco Control. The research was funded by the U.S. National Cancer Institute.

The study authors noted that an estimated 70 percent of smokers interviewed said they wanted to quit, and more than 45 percent said they made an effort to do so in the past year.

The researchers looked at the experiences of nearly 800 Massachusetts residents who had recently quit smoking before enrolling in the study.

During three two-year “waves” (starting in 2001 and ending in 2006), each of the participants was asked about any nicotine replacement therapy use, which in addition to patches or gums could also include nicotine inhalers and nasal sprays. All were also asked if they had received counseling from a doctor or other professional, or whether they had joined any program designed to help them quit. Relapse rates were also noted.

The result: Within each two-year survey time frame, about one-third of the quitters had begun to smoke again. Nicotine replacement therapy appeared to have no impact on the relapse rate, meaning that those who used the therapy for six weeks or longer were as likely to relapse as those who hadn’t.

The study authors concluded that the findings raise “serious questions” about the effectiveness of nicotine replacement therapy as experienced by most smokers: namely, outside a carefully controlled clinical setting.

The researchers suggested that the findings might have broad public health implications, given pending plans under the federal health reform law that Medicare, Medicaid and private insurance plans cover the costs of nicotine replacement therapy.

“The FDA (U.S. Food and Drug Administration) has the responsibility for regulating medications to help smokers quit, as well as new responsibilities concerning tobacco products themselves,” Alpert said. “So, on the one hand, it (the FDA) should only approve medications that are proven to be effective in helping smokers quit long-term. And it has the authority to intervene to actually reduce the addictiveness of cigarettes, which is what this study suggests is the real issue rendering NRT ineffective.”

Stanton Glantz, a professor of medicine in the division of cardiology at the University of California, San Francisco’s Center for Tobacco Control Research and Education, said the new study “is a real challenge to the routine use of over-the-counter NRT outside of a clinical setting.”

“The findings don’t surprise me,” he added. “And they perhaps serve as an important cautionary tale about the way we might want to use our public dollars, and what is, and what is not, good public health policy.”

“For example, we already know that increasing the price of cigarettes, public messaging, and strong legislation restricting indoor smoking work, and work very well, as a matter of policy,” Glantz noted. “But this study suggests that NRT doesn’t actually buy you anything when used over the counter. So using public funds to support NRT use in that way may not be such a great idea.

“But at the same time,” he added, “this is just one study, and it’s not terribly huge. And this study isn’t saying that these pharmacologic aids don’t work at all. It just says that NRT doesn’t work in the unsupervised, over-the-counter context. So we don’t necessarily want to throw out the baby with the bathwater.”