More Americans are giving up cigarettes, and a new study suggests electronic cigarettes may be the reason why.

After stalling for 15 years, the U.S. quit-smoking rate rose to nearly 6 percent in 2014-2015, up from less than 5 percent in prior years, according to national survey data.

Researchers at the University of California, San Diego School of Medicine believe e-cigarettes have helped fuel the increase.

“From 2014 to 2015, more e-cigarette users tried to quit cigarette smoking and succeeded in quitting than those who didn’t use e-cigarettes,” said lead researcher Shu-Hong Zhu, director of the university’s Center for Research and Intervention in Tobacco Control.

Reviewing survey responses from nearly 25,000 current and former smokers in 2014-2015, Zhu and his colleagues found that “vapers” were more likely than nonusers to make a quit attempt (65 percent versus 40 percent). And they were more likely to succeed for at least three months (8 percent versus 5 percent), he said.

A 1 percent increase in the smoking cessation rate represents about 350,000 additional smokers, Zhu said.

In background notes, the researchers said use of electronic cigarettes in the United States became noticeable around 2010 and increased dramatically by 2014 — which would coincide with the rising quit-smoking rates.

But scientists remain divided over whether e-cigarettes are a “gateway” to smoking or a less harmful tool that helps smokers quit. This new study seems to support the second theory.

“People should be open to consider e-cigarettes as a way to help them quit, especially if they have used everything else in the past,” Zhu said. “The important thing is that people continue to try.”