The Global Initiative for Chronic Obstructive Lung Disease (GOLD) provides criteria for the diagnosis and management of chronic obstructive pulmonary disease (COPD). Although all patients may have their own unique course with COPD, the GOLD stages are a good starting place for clinicians to determine COPD severity.
The GOLD stages of COPD categorize the disease by severity to help clinicians manage symptoms, slow the progression, and improve quality of life. The four stages range from mild disease to very severe.
How Prevalent is COPD?
According to the American Lung Association, COPD is the 3rd leading cause of death in the United States. It is estimated that over 16 million people have a COPD diagnosis. COPD often involves a combination of symptoms that include breathlessness, wheezing, and fatigue.
COPD should be considered in any patient that has shortness of breath, chronic cough, and a history of exposure to risk factors, including smoking, occupational dust, vapors, fumes, or other chemicals. Diagnostic testing that may help confirm a diagnosis includes:
- Imaging to rule out other lung conditions
- Pulmonary function tests
- Arterial blood gas measurement
- Exercise testing
What Are the COPD Gold Stages?
COPD GOLD stages are determined by the results of a pulmonary function test. One main test used is the forced expiratory volume test (FEV1). The FEV1 measures the volume of air someone can exhale in one second.
The FEV1 is compared with predicted values expected in a healthy person of similar gender, body size, ethnicity, and age. Typically, people with COPD can blow out anywhere from about 80 % of predicted to less than 30 %, depending on the severity of their lung disease.
Below are the four stages of COPD:
Stage 1: Stage one indicated mild COPD. The percentage of predicted FEV1 is 80% or greater. Although it can vary, symptoms may also be mild. Some people may not even experience symptoms.
Stage 2: Stage 2 is moderate disease. FEV1 is 50 to 79%. Symptoms may be noticeable at this stage.
Stage 3: Stage 3 is considered severe disease. FEV1 is 30 to 49% of predicted. Symptoms may become more severe and exacerbations more frequent.
Stage 4: Stage 4 signals very severe disease. FEV1 is 29 % or less of predicted. At this stage, symptoms may occur daily, and life expectancy is significantly decreased.
What is the COPD Assessment Test (CAT)?
Spirometry provides insight into airflow limitations but does not tell the entire story. Individual patient symptoms help determine which therapeutics may be most effective.
In the past, the level of breathlessness played a large part in assessing symptoms. But researchers determined that COPD impacts people beyond just shortness of breath. Recommendations now include performing an assessment using the COPD Assessment Test (CAT), which identifies and determines the severity of different symptoms associated with COPD, such as cough, chest tightness, fatigue, and phlegm.
An individual with COPD rates their symptoms from 0 to 5 based on how much they impair day to day functioning. The test is tabulated, and the results are scored from 0 to 40. The higher the number, the more the symptoms interfere with daily life. Clinicians should also consider the number of COPD exacerbations to determine the risk for future flare-ups.
Treatment for COPD by stage and symptoms
Classification and assessment of COPD include combining the symptom assessment along with spirometry and exacerbation history to develop a treatment plan for COPD. The GOLD stages indicate the severity of airflow limitations. But the CAT score provides information regarding symptoms. Including the assessment of symptoms and exacerbation history helps a doctor consider the whole patient and not just look at numbers, such as the FEV1 percentage.
The treatment for COPD depends on the stage of disease and symptoms. The initial management of COPD includes:
- Smoking cessation
- Flu vaccination to prevent infection
- Education, such as spacer training and pulmonary rehab classes
- Management of comorbidities
Keep in mind, although the stage of COPD plays a role in selecting treatment, it is not a one size fits all approach to managing COPD. For example, one person that is stage 3 COPD may have less severe symptoms than someone else that is the same stage.
In general, initial medication management for stable COPD with only occasional dyspnea may include one short-acting beta-agonists bronchodilator (SABA). People with stage 1 or 2 and a low CAT score may have stable COPD.
A SABA relaxes the smooth muscle in the airways, which leads to dilation and potentially a reduction in chest tightness, wheezing, and shortness of breath. Examples of a SABA include:
Long-acting beta-agonist bronchodilators may also be used to manage COPD, especially in stage 2 or later. This class of medication also relaxes the muscles of the airways but lasts longer than SABAs. Examples of LABAs include:
Inhaled corticosteroids (ICS) should be considered in some cases, such as when COPD is not well controlled with bronchodilators. ICS reduce inflammation in the airways. In some cases, people with stage 3 and 4 COPD may require additional medication management, such as inhaled corticosteroids or combination LABA/ICS.
Common LABA/ICS medications include:
Additional treatment, including antibiotics, oxygen therapy, and BiPAP, may also be considered, especially in the later stages of COPD.
When determining the most appropriate COPD treatment plan, the GOLD stages of COPD, along with the CAT score and exacerbation history, are helpful. But the management of COPD must also consider access, cost, and patient preference.