The number of people diagnosed with pulmonary disease such as chronic bronchitis and emphysema increased nearly 65 per cent over a decade, according to a new Ontario study.

The prevalence of chronic obstructive pulmonary disease (COPD) among adults over age 35 increased 64.8 per cent from 1996 to 2007, researchers from the Institute for Clinical Evaluative Sciences (ICES) reported in Monday's issue of the Archives of Internal Medicine.

'Many people with COPD I see have quit already or they were exposed to second-hand smoke and they get the disease.'—Dr. Andrea Gershon

COPD is a progressive and irreversible blocking of the airway that is usually caused by emphysema and chronic bronchitis. There is no cure but it can be prevented and mitigated with treatment.

The symptoms of COPD — shortness of breath and coughing — emerge over time, usually after age 55. Today's COPD patients likely started smoking decades ago.

More than 700,000 Ontarians over 35 — 10 per cent of the province's adult population — live with this disease.

"Despite improvements in overall survival, it remains the fourth leading cause of death in North America and the leading cause of hospitalization in Canada," said the study's principal investigator, respirologist Dr. Andrea Gershon.

Gershon, an ICES scientist in Toronto, said its the first known large-scale study to examine the prevalence of COPD over time and document its upward trend. The results likely apply to the rest of Canada and other developed countries, Gershon said.

In the long run, Gershon said, she hopes COPD will be defeated through smoking prevention programs.

Mortality rate fell less for women

"Smoking bothers me and it bothers me when I see people smoking, but I also don't think that awful things should happen to them. And many people with COPD I see have quit already or they were exposed to second-hand smoke and they get the disease."

Some female COPD patients were exposed to second-hand smoke from their husbands, she noted.

"It breaks my heart," Gershon said. "Obviously, there's lots of parts of the profession that are tough, but that's one of them."

The other tough part for Gershon is telling people who quit smoking 20 years ago that they have COPD anyway.

Overall, the age- and sex-standardized mortality rate from all causes among people with COPD decreased from 5.7 per cent in 1986 to 4.3 per cent in 2007. The decrease was greater in men, 25.9 per cent, compared with women at 21.2 per cent.

Several factors may be contributing to higher COPD survival, including:

• Lower smoking rates.
• Better treatments for comorbidity — other diseases that often kill people with COPD, such as heart disease.
• Introduction of COPD treatments in the last 20 years such as medications that prevent hospitalization and emergency department visits, and pulmonary rehabilitation.

Given how common COPD is among adults, Gershon said, it's a public health concern for society.

Government smoking cessation programs are a great start, she said, but there could also be programs to help people with COPD to quit, get medications and get pulmonary rehabilitation — a combination of physiotherapy exercises, education and occupational therapy to help maximize what people can do with their reduced lung function so they don't spiral downwards.

In 2008, researchers in Quebec called pulmonary rehabilitation the best treatment to improve shortness of breath and quality of life for people with COPD, but noted only two per cent of patients in Canada are offered it.

The study was funded by the Ontario Ministry of Health and Long-Term Care, the Canadian Institutes of Health Research, Public Health Agency of Canada, University of Toronto and ICES.