Its subjects were 29,000 Finnish men aged 50 and up, all of them long-term smokers.
Up to half of all long-term smokers will prematurely develop a debilitating disease, most often heart disease, chronic lung disease or cancer.
As of January 30, 2013, all cigarette packages must include graphical warning labels that show the detrimental effects on the health of long-term smokers.
Out of every 100 long-term smokers, about 15 to 20 get COPD with symptoms.
The industry suffered a stunning legal setback when a Florida jury awarded a long-term smoker $750,000 for damages caused by his habit.
About 1 in 4 long-term smokers will get COPD, if they live long enough.
Between 15% and 20% of long-term smokers will develop COPD.
Heavier or more long-term smokers may need extra help: smoking cessation drugs can be prescribed and have been proven to be successful.
Everyone in the tobacco debate agrees that reducing youth smoking would have major benefits because nearly all long-term smokers start as teen-agers.
In trials the drug beat a placebo among long-term smokers who had averaged 21 cigarettes a day for about 25 years.