A study by the federal Agency for Healthcare Research and Quality found that nearly 38 percent of people with the chronic lung disease emphysema still smoke, as do almost 25 percent of those with asthma.
And the agency said Tuesday that the patients continued smoking even though at least 60 percent of them said they had been told by a doctor to stop within the last year.
The federal Centers for Disease Control and Prevention reports that about 15 million Americans suffer from asthma. The American Lung Association estimates the number may be as high as 17.7 million, with an additional 2.8 million suffering from emphysema.
The agency's Dr. Steven B. Cohen said the data will allow researchers to detect trends and determine whether people with chronic illnesses continue to smoke in large numbers in coming years. AHRQ is the government's lead agency for research on health care quality, costs, outcomes and patient safety.
"We're trying to assess the individuals who are current smokers and get a sense of whether, in the past 12 months, they have been advised to quit," Cohen said.
The findings were no surprise to Dr. Norman H. Edelman. "We see people like that all the time," the Long Island physician said.
"What it points out is nicotine is a true addiction, just like being addicted to heroin or cocaine or other narcotics. You are perfectly aware of deleterious effects but it's hard to break an addiction," said Edelman, who teaches at the State University of New York at Stony Brook.
The findings, part of a statistical brief on smoking, were issued without discussion by the Health and Human Services agency.
The report also noted that 20 percent of people with high blood pressure or heart problems continue to smoke, as do 18.5 percent of people with diabetes, diseases that affect millions more Americans.
Cohen said that the overall statistics on the number of adults who smoke are similar to other studies, but those studies haven't looked specifically at people with chronic illnesses.
Edelman, who serves as a spokesman for the American Lung Association, said that in addition to the problems of quitting smoking, some people who develop disease take the attitude that the damage is already done so they may as well continue to enjoy cigarettes.
But, he stressed, research has shown that it's always beneficial to stop smoking.
"Physicians have to be much more active in helping people quit," he said. "They have to recommend programs, they have to monitor programs, make sure patients are using pharmaceutical aids to quit. In general, we believe physicians should play a more active role" in helping people quit.
The new findings are based on a self-administered questionnaire given to 15,661 adults in late 2000 and early 2001 as part of an effort to evaluate their health care.
Overall, the report found that 23.1 percent of adult Americans smoke. The Centers for Disease Control and Prevention reported earlier that 23.3 percent were smokers in 2000, down from 25 percent in 1993.
The new study found the lowest smoking rates among Hispanics, 16.8 percent. By comparison 23.6 percent of non-Hispanic blacks smoke, as do 23.8 percent of non-Hispanic whites and other persons.
As other studies have shown, people who didn't finish high school are more likely to smoke than those who graduated, 32.8 percent compared to 15.8 percent.
And, at 54.6 percent, men made up more than half of smokers.