The study included 568 adults who smoked 10 or more cigarettes a day for at least the past year. The smokers who used nicotine patches for the entire 24 weeks of the study (extended therapy) were about twice as prone to quit smoking as those who used nicotine patches for eight weeks and then received placebo patches for the remainder of the study. Standard therapy — as recommended by manufacturers — is eight weeks.

By the end of the study, 31.6 percent of extended-therapy participants had not smoked in the past seven days, compared to 20.3 percent of those on standard therapy. More than 19 percent of those in the extended-therapy group did not smoke at all during the study, compared to 12.6 percent of those in the standard-therapy group, the study authors noted.

In addition, smokers on extended therapy abstained from cigarettes longer and were more apt to stop smoking again if they suffered a relapse, according to the report in the Feb. 2 issue of the Annals of Internal Medicine.

“Our data suggest that the many smokers who relapse while trying to quit will be especially helped by extended treatment, which appears to make it easier for smokers to ‘get back on the wagon’ after a small smoking slip, instead of having it turn into a full-blown relapse,” study author Robert Schnoll, an associate professor of psychiatry at the University of Pennsylvania School of Medicine, stated in a university news release.

After one year, participants in both the extended-therapy and standard-therapy groups had similar rates of smoking abstinence — 14.5 percent and 14.3 percent, respectively. But those in the extended-therapy group were more likely (29.1 percent) to report periods of smoking abstinence lasting more than seven days in a row during the year than those in the standard-therapy group (21.3 percent).