If you don't quit smoking, there's a 67 percent chance it'll kill you, study says

This Tuesday, July 15, 2014 photo shows the tobacco in cigarettes in Philadelphia. A study ties a host of new diseases to smoking, and says an additional 60,000 to 120,000 deaths each year in the United States are probably due to tobacco use. The study by the American Cancer Society and several universities is published in the Thursday, Feb 12, 2015 edition of the New England Journal of Medicine. It looks beyond lung cancer, heart disease and other conditions already tied to smoking and adds breast cancer, prostate cancer and even routine infections to the list. (AP Photo/Matt Rourke)

In case you weren't convinced of the dangers of smoking, a new study offers a stark figure: Up to two-thirds of those who continue smoking will die as a result, researchers say in a press release.

The Australian study was a big one, based on assessments of the health of 200,000 people over four years; the men and women are part of the southern hemisphere's biggest longitudinal study on aging, the release notes.

"We found that smokers have around threefold the risk of premature death of those who have never smoked," says researcher Emily Banks. "We also found smokers will die an estimated 10 years earlier than non-smokers." That was true for both men and women, Banks says, as the Sydney Morning Herald reports.

The two-thirds figure supports similar results from the UK and US. The average smoker in the study kept up the habit for 38.5 years, and the majority smoked at least 15 cigarettes daily.

That's particularly worrying given that mortality rates were about twice as high "in those smoking around 10 cigarettes per day." A pack a day means death rates fourfold or fivefold what a nonsmoker experiences, the study finds.

"Our findings are an important reminder that the war on tobacco is not yet won, and tobacco control efforts must go on," Banks notes. Looking on the bright side, the study shows "it's never too late to quit, no matter what your age or how much you smoke," says another expert, as HealthDay News reports.

(Another recent study finds that smoking kills more people than we thought.)

This article originally appeared on Newser: Keep Smoking, and There's a 67% Chance It'll Kill You