Smoking can dramatically increase the risks of peripheral artery disease (PAD), which restricts blood flow to the extremities and can lead to mobility limitations, amputations and heart attacks. For the current study, researchers examined data on 1,272 patients in Australia, the Netherlands and the U.S. with new or worsening PAD symptoms in their legs and ankles.
Overall, one third of patients were current smokers, but fewer than one in five were referred to smoking cessation counseling and just one in 10 were prescribed a medication to help them quit.
The study offers fresh evidence of just how difficult smoking cessation can be.
Researchers checked with patients on their smoking status when they started the study and again after three, six and 12 months.
After three months, the smokers' odds of quitting were just 21 percent.
Among smokers who hadn't quit at that point, their odds of quitting over the next nine months ranged from 11 to 12 percent.
Slightly more than one-third of people who initially managed to quit relapsed and started smoking again, the study also found.
And at 12 months, 72 percent of smokers continued to smoke.
The study wasn't designed to prove whether or how more physician support might directly impact smokers' odds of successful cessation.
One limitation of the study is that researchers relied on patients to accurately report on any smoking history or cessation efforts, and it's possible some people provided incorrect information, the authors note in the Journal of the American Heart Association.
Researchers also lacked data on what factors might have influenced doctors' decisions about whether to recommend counseling or medications to smokers to aid with cessation.
There are many reasons doctors might not intervene to help smokers quit, said Dr. Joseph Ladapo, a researcher at the David Geffen School of Medicine of the University of California, Los Angeles, who wasn't involved in the study.
Sometimes, smoking cessation is not high on the physician's priority list for the patient, and other times doctors may not know or may not ask a patient about current smoking habits, Ladapo said by email. Other times, doctors might not realize that counseling patients in the office can be effective.