(CNN) — Just the thought of quitting cold turkey is probably enough to make any smoker uneasy. But a new study adds support to the notion that people who give up cigarettes all at once are more likely to be successful than those who wean themselves off gradually.

Researchers looked at nearly 700 long-term heavy smokers in England who wanted to kick the habit. They instructed half of the participants to quit abruptly — that is, pick a quit day when they would give up smoking entirely. The other half were told to scale back their cigarettes gradually for two weeks leading up to their quit day.

But even the abrupt-quit group was not exactly going it alone. The researchers gave them nicotine patches to use for two weeks before their quit day. During this period, the gradual group also got patches, as well as gum, lozenges and other types of short-acting nicotine replacement therapy to help them as they cut back. After the quit day, both groups got patches and short-acting therapy, in addition to counseling.

The researchers found that 49% of the participants in the abrupt-quit group were not smoking by one month after their quit day, compared with 39.2% in the gradual-quit group. By six months, success rates had dropped, but the difference between the groups was still there: 22% of the abrupt quit group was not smoking, compared with 15.5% of the gradual-quit group.

Even though the more cold turkey method came out on top, the quit rates for both methods were still “quite good,” said Nicola Lindson-Hawley, a postdoctoral researcher at the Nuffield Department of Primary Care Health Sciences at the University of Oxford in England. Lindson-Hawley is the lead author of the study, which was published Monday in the Annals of Internal Medicine.

“Health care workers should offer abrupt quitting first, but if that is not an option, gradual quitting can be a second-line approach,” Lindson-Hawley said. “We understand that people might be dead set against quitting abruptly so if the only way they would consider quitting is gradually then the results of this trial suggest it shouldn’t be ruled out.”

Guidelines on smoking cessation generally urge smokers to quit abruptly. Although some studies have seen no difference between the methods, others suggest that going cold turkey could yield higher success rates.

The high success rates in the current study for both groups is in line with the level of abstinence in the general population achieved through the Stop Smoking Service in the UK, which offers social support and nicotine replacement therapy, Lindson-Hawley said.

But rates are much lower when people people try to go it alone, Lindson-Hawley said. Only a small number of people get help to quit smoking, and a small number of people in the general population — about 5% to 7% — manage to remain smoke-free a year after quitting.

“There is really good evidence for nicotine replacement therapy like patches and gum, that are also very safe, and also Chantix (varenicline)” to help people quit smoking, Lindson-Hawley said.

In addition to the method of quitting, a person’s attitude about quitting may help determine whether he or she will be successful. The current study found that participants who preferred trying to quit abruptly before the study started — suggesting they were especially motivated to quit — were also more likely to be kick the habit.

In the abrupt quit group, rates of abstinence at four weeks were 58% among participants who had wanted to quit cold turkey, but only 42% among those who had preferred quitting gradually. In the gradual quit group, success rates at four weeks were 45.8% and 34.6% among those who had wanted to quit cold turkey or gradually, respectively.

“There are two things that are important in quitting. One is confidence, belief in your ability to be successful. … And the second is desire, the commitment to do it,” said Michael P. Eriksen, dean of the Georgia State University School of Public Health, who was not involved in the current study.

The study did not detect a difference in the confidence levels between the two groups.

“One of the implications [of this study] is we need to really get people to understand that quitting cold turkey is more effective, it kind of gets it over with,” Eriksen said.

For her part, Lindson-Hawley suspects that quitting gradually might leave people out in the cold by prolonging cravings and withdrawal symptoms.

“We hypothesize that you get it all out of the way in one go [by quitting abruptly]. In the gradual group, because they were put through it in a gradual way, they lost the motivation,” Lindson-Hawley said. In support of this possibility, the study found that fewer participants in the gradual quit group managed to actually quit on their predetermined quit day, as compared with the abrupt quit group.

“Rather than discouraging people from quitting at all, [the findings] will encourage them to quit abruptly, to go cold turkey and line up whatever support you need,” which can include nicotine replacement therapy, setting up counseling or locating quit lines you can call, Eriksen said.

“I used to smoke and stopped cold turkey and never touched a cigarette since and it’s been over 40 years,” Eriksen said. “To me it was really a matter of doing it and being fed up, but also liking smoking and knowing I couldn’t stop gradually.”