Chronic obstructive pulmonary disease (COPD) is a term used to describe a group of chronic lung diseases including chronic bronchitis and emphysema. COPD makes it more difficult to breathe and overtime this can get worse.
Two main assessment systems - GOLD stages 1 to 4 and GOLD ABCD - are used to determine your stage and grade of COPD.
The information gathered during these assessments is important because it is used to help diagnose, manage and monitor COPD.
Spirometry is a test used to help determine what stage of COPD you have
Spirometry is the name given to the breathing or pulmonary function test used to help determine how well your lungs work and the stage of COPD you have. It measures how much your airways or bronchial tubes may have narrowed.
It is a simple and painless test which involves blowing into a plastic mouthpiece connected to the spirometry machine.
Two of the things that spirometry measures are forced expiratory volume in one second (FEV1) and forced vital capacity (FVC).
FEV1 measures the maximum amount of air that you can forcibly breathe out in one second. FVC is the maximum amount of air that you can forcibly exhale in one breath while breathing out as fast as you can.
The ratio between these two - the FEV1/FVC ratio - indicates how much air you can forcibly exhale from your lungs.
The results from spirometry tests are used to help diagnose and monitor COPD and other conditions. When used to assess COPD, at least one short-acting inhaled bronchodilator drug - a drug that opens up the airways - is administered before spirometry is carried out to reduce the variability in results.
The GOLD system uses results from spirometry to classify COPD into 4 stages
COPD results in less air flowing into and out of a person’s airways. A FEV1/FVC ratio of less than 70 percent indicates that a person has airflow limitations and possibly COPD.
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) has developed a classification system that categorizes COPD into 4 stages based on airflow limitation severity.
The 4 GOLD stages used to classify airflow limitation severity in people with COPD (FEV1/FVC ratio of less than 70 percent) are listed in the table below.
|GOLD 1||Mild||FEV1 ≥ 80% predicted|
|GOLD 2||Moderate||50% ≤ FEV1 < 80% predicted|
|GOLD 3||Severe||30% ≤ FEV1 < 50% predicted|
|GOLD 4||Very severe||FEV1 < 30% predicted|
GOLD also uses the ABCD grading system to better understand the impact of COPD on an individual
The 4 GOLD stages listed above are used to classify a person’s airflow limitation severity. They are just one part of the GOLD assessment system for COPD.
In addition to the 4 GOLD stages, GOLD has also introduced questionnaires, as part of its ABCD grading system, to learn more about how much of a burden people find their COPD symptoms.
The two questionnaires used are the:
- Modified British Medical Research Council (mMRC) Questionnaire - used to assess breathlessness (dyspnea). mMRC asks a patient to describe their degree of breathlessness using a scale. The scale ranges from mMRC Grade 0 - I only get breathless with strenuous exercise - through to mMRC Grade 4 - I am too breathless to leave the house or I am breathless when dressing and undressing.
- COPD Assessment Test (CAT) - used to assess a range of COPD symptoms. CAT asks patients a series of questions and gets them to rate them on a scale of 0 to 5. CAT asks about how much you cough, how much phlegm you have, how tight your chest feels, how breathless you get walking up stairs or a hill, if you have to limit activities at home, how confident you are leaving your home, how well you sleep and how much energy you have. CAT scores range from 0-40.
The information from the questionnaires is combined with a person’s history of moderate to severe exacerbations or flare-ups of their COPD to determine their GOLD ABCD grade.
COPD ABCD grade
Low symptoms, low risk
High symptoms, low risk
Low symptoms, high risk
High symptoms, high risk
COPD and life expectancy
COPD is a chronic illness rather than a terminal disease. Mild COPD that is diagnosed early and well-managed may have little or no impact on a person’s life expectancy. People with severe COPD, however, lose about 8-9 years of life on average.
The exact life expectancy of a person with COPD will vary depending on a range of factors including the results of their GOLD assessments, their age, health and other factors such as smoking status.
The results of the BODE (Body mass index, Obstruction, Dyspnea and Exercise) Index may be used to help predict survival. The BODE Index looks at a range of different variables and provides a composite score that is more accurate than looking at the variable alone. The BODE method looks at:
- Body mass index (BMI, kg/m2)
- Airflow Obstruction (FEV1)
- Dyspnea or breathlessness (mMRC)
- Exercise capacity (distance walked in 6 minutes)
|FEV1 (% predicted)||
|Distance walked in 6 minutes||≥350||250-349||150-249||≤149|
People with a lower BODE Index score are expected to have a higher life expectancy than those with a higher score.
Healthcare professional use classifications systems to determine what stage and grade of COPD you have, including:
- GOLD stages 1 to 4 (spirometric grades) to measure the severity of your airflow limitation
- GOLD ABCD groups to determine your symptom burden and risk of exacerbation
This comprehensive approach provides them with the information they need to diagnose, treat and monitor COPD.
The life expectancy of people with COPD varies greatly depending on a range of different factors. Check out our tips here for improving your quality of life if you have COPD.
- Asthma and Respiratory Foundation NZ. What Is Spirometry? Available at: https://www.asthmafoundation.org.nz/your-health/living-with-copd/what-is-spirometry. [Accessed March 22, 2022].
- American Lung Association. What Is Spirometry and Why It Is Done. February 19, 2020. Available at: https://www.lung.org/lung-health-diseases/lung-procedures-and-tests/spirometry. [Accessed March 22, 2022]
- Global Initiative For Chronic Obstructive Lung Disease (GOLD). Website. Available at: https://goldcopd.org/. [Accessed March 22, 2022].
- Global Allergy & Airways Patient Platform (GAAPP). COPD Life Expectancy. Available at: https://gaapp.org/copd/life-expectancy/. [Accessed March 22, 2022].
- Celli BR, Cote CG, Marin JM, et al. The body-mass index, airflow obstruction, dyspnea, and exercise capacity index in chronic obstructive pulmonary disease. N Engl J Med. 2004;350(10):1005-1012. doi:10.1056/NEJMoa021322.