Chronic Obstructive Pulmonary Disease, or COPD, refers to a group of diseases that cause airflow blockage and breathing-related problems, including emphysema and chronic bronchitis.
Chronic lower respiratory disease, primarily COPD, was the third leading cause of death in the United States in 2014.
Tobacco smoke is a key factor in the development and progression of COPD in the United States, although exposure to air pollutants in the home and workplace, genetic factors, and respiratory infections also play a role.
Almost 15.7 million Americans -- 6.4% -- reported that they have been diagnosed with COPD, but the actual number may be higher, as COPD is known to be underdiagnosed.
The prevalence of COPD generally increases with age. An estimated 24% of all Americans 65 years and older have COPD.
Although the primary cause of COPD is smoking, studies have also shown strong links between exposure to indoor and outdoor air pollution and COPD.
The most common indoor exposures are smoke from tobacco, fireplaces and wood stoves, while outdoor exposures include ozone and particle pollution, and emissions from vehicles and industrial sources. Job-related exposures include fumes, gases, and dusts.
In 2003, the American Thoracic Society showed that about 19% of all COPD cases were attributable to occupational exposures, with 31% in people who have never smoked.
Many people with COPD also have other chronic diseases, with asthma being the most common. People with active asthma were estimated to be 10 times more likely to develop chronic bronchitis, and 17 times more likely to develop emphysema compared to those without asthma. Prior respiratory infections are also a key risk factor for COPD.
COPD is also strongly associated with cardiovascular disease. One study of 45,000 patients with COPD, showed heart failure, myocardial infarction, and stroke were leading causes of death. Another study found that the prevalence of all cardiovascular diseases was higher in patients with COPD, resulting in higher risk of hospitalization and death.
Vermont Tracking provides annual data about hospitalizations for COPD starting in 2001, and emergency department visits for COPD starting in 2003.
Hospitalizations are inpatient admissions of Vermont residents to hospitals in Vermont, New Hampshire, New York, and Massachusetts. Emergency department visits are emergency room visits to Vermont, New Hampshire, New York, and Massachusetts hospitals by Vermont residents.