Smokers who wore nicotine patches for six months were twice as likely to quit as those who unknowingly received placebos after wearing real patches for two months, according to a new study.

However, smoking rates were the same among both groups a year after the study began, Reuters reported Feb. 1.

Study author Caryn Lerman of the University of Pennsylvania School of Medicine and colleagues found that the outcomes for long-term patch use with similar to those found among patients taking the medications Chantix or Zyban. Lerman said the findings suggest that “we may need to reconsider our guidelines about the length of treatment and consider, at least for some smokers, longer-term therapy.”

The study tracked 568 daily smokers. It was published in the Annals of Internal Medicine.