A large new survey across four countries has found that smokers attempting to quit have considerably more success when they use nicotine patches or prescription medications than when they go it alone without anti-smoking aids.
Past research has yielded conflicting evidence on the effectiveness of drug treatments for smoking cessation - they seem to help in clinical trials, but to make less of a difference in real-life settings.
How the study was done
When researchers accounted for differences between those who tried to quit with the help of medications and those who went 'cold-turkey' - including their respective recollections of past quit attempts - the new study, published online in Addiction, found some quitting aids were linked to four- to six-fold higher success rates.
"This study confirms that the positive result seen in clinical trials translates into the real world," said Dr Saul Shiffman, a psychologist at the University of Pittsburgh who was not involved in the research.
Karin Kasza at Roswell Park Cancer Institute in Buffalo, New York and her colleagues surveyed more than 7400 adult smokers in the U.S., Canada, Australia and the UK, then tracked those individuals to see how many had succeeded in staying smoke-free for at least six months.
About 2200 people used a prescription medication or nicotine replacement therapy, the rest did not.
Among those who used no medication to quit, 5% remained abstinent from cigarettes for six months. In comparison, 16% of nicotine patch users, 15% of people who used bupropion (Zyban), and 19% of people who used varenicline (Chantix) stayed off cigarettes for six months.
What the study found
After taking into account factors that could affect people's success, such as how long and how heavily they had smoked, the researchers determined that bupropion and the nicotine patch were each tied to a four-fold increase in quitting success compared with no medications, and varenicline to a nearly six-fold increase.
8% of people who used oral nicotine replacement products, such as gum, stayed abstinent for six months - but the difference relative to those using no quitting aids was not statistically significant.
Of the high quit rates among people using drugs or patches, Kasza said that previous studies in real-world settings have not shown as much success, so her findings are unexpected.
"But compared to clinical trial results, this is much closer in line with what they found," she said.
Kasza believes the difference between her studies and others is the reliance of this kind of investigation on memory.
Previous research has found that people who do not use medications to help them quit are less likely to remember a failed quit attempt than are people who failed to quit while using medications.
In other words, if you ask people about their past experiences in trying to quit smoking, "if they're without treatment, they forget them. If they're with treatment, they remember them," explained Dr John Hughes, a psychiatrist at the University of Vermont who was not involved in the new study.
Not a magic bullet
"Since they're now current smokers, they're remembering the (attempts) that failed with treatment and not the ones that failed without," he said.
This would over-represent the times that people failed to quit while using medications, making the drugs appear less helpful.
To get around the problem, Kasza's group asked people at the outset of the study to recall past attempts to quit within the last month, to ensure the memories were fresh.
They also included only abstinence attempts that lasted longer than a day, to exclude less "serious" resolutions to give up cigarettes.
Overall, the researchers found, people who tried to quit without any aids were likely to be younger, have lower incomes, be less addicted to nicotine and have higher confidence in their ability to break the smoking habit than those who used medications.
Dr Hughes, who, like Dr Shiffman, has been a consultant for companies that market smoking-cessation drugs, said the current study is the best to date comparing medication users to non-users in real-world situations because it is large, it includes people from several countries and it takes into account the influence of memory.
The study does not prove that the medications are responsible for the greater success in quitting, but merely that people who use them are more likely to quit.
Dr Shiffman said that based on the number of studies that have found a positive effect from anti-smoking drugs, it is worth it for smokers to give them a try.
"The disappointing reality is that even when people use these medications to help them quit," Kasza said, "relapse is still the norm. It's better than nothing, but it's by no means a magic bullet."
(Reuters Health, September 2012)
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