From the Guidelines
Chronic Obstructive Pulmonary Disease (COPD) is classified into four stages based on symptoms and lung function. The classification of COPD can be based on either the American Thoracic Society (ATS)/European Respiratory Society (ERS) criteria or the Global Initiative of Chronic Obstructive Lung Disease (GOLD) criteria, as outlined in 1.
Classification Based on ATS/ERS Criteria
- Mild: Forced Expiratory Volume in one second (FEV1) ≥ 70% predicted
- Moderate: FEV1 60-69% predicted
- Moderately severe: FEV1 50-59% predicted
- Severe: FEV1 35-49% predicted
- Very severe: FEV1 < 35% predicted
Classification Based on GOLD Criteria
- Mild: FEV1/FVC < 0.70 and FEV1 ≥ 80% predicted
- Moderate: FEV1/FVC < 0.70 and 50% ≤ FEV1 < 80% predicted
- Severe: FEV1/FVC < 0.70 and 30% ≤ FEV1 < 50% predicted
- Very severe: FEV1/FVC < 0.70 and FEV1 < 30% predicted or FEV1/FVC < 0.70 and FEV1 < 50% predicted with chronic respiratory failure, as stated in 1. However, the GOLD 2017 report, as mentioned in 1, refines the assessment of COPD by separating spirometric assessment from symptom evaluation, proposing ABCD groups derived from patient symptoms and history of exacerbations. The treatment typically involves a combination of medications, including bronchodilators and inhaled corticosteroids, with pulmonary rehabilitation and oxygen therapy recommended for advanced stages.
From the FDA Drug Label
The efficacy and safety of roflumilast in COPD was evaluated in 8 randomized, double-blind, controlled, parallel-group clinical trials in 9394 adult patients (4425 receiving roflumilast 500 mcg) 40 years of age and older with COPD The classification of Chronic Obstructive Pulmonary Disease (COPD) is not explicitly stated in the provided drug labels. COPD is described as a condition with nonreversible obstructive lung disease characterized by an FEV1/FVC ratio ≤70%.
- The severity of airflow obstruction is categorized based on the FEV1 percentage predicted, with ranges including:
- Mild: not specified
- Moderate: 40% to 70% predicted
- Severe: ≤50% predicted
- Very severe: ≤30% predicted However, the labels do not provide a clear classification system for COPD. 2
From the Research
Classification of Chronic Obstructive Pulmonary Disease (COPD)
The classification of COPD is based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) severity stage, which categorizes patients into groups based on:
- Symptoms
- Exacerbations
- Forced expiratory volume in one second (FEV1) 3 The GOLD classification system splits patients with COPD into four categories: A, B, C, and D, based on the level of symptoms and risk of future exacerbations 4.
GOLD Classification Categories
The four categories of the GOLD classification system are:
- Category A: Low risk, fewer symptoms
- Category B: Low risk, more symptoms
- Category C: High risk, fewer symptoms
- Category D: High risk, more symptoms 4 The GOLD classification system has undergone revisions, with the 2017 revision introducing changes to the classification categories 5.
Clinical Utility of the GOLD Classification
The GOLD classification system has been shown to be useful in discerning groups of COPD patients, but it may not be adequate as a basis for individual management plans in rehabilitation due to large inter-individual variability 6. The classification system has been found to be associated with outcomes such as mortality and hospitalizations, with patients worsening in COPD severity having a stepwise increased mortality and hospitalizations 3.
Comparison of GOLD Classifications
Comparisons of the GOLD 2011 and GOLD 2017 classifications have shown moderate agreement between the two classifications, with approximately half of the patients classified as GOLD D 2011 changing to GOLD B 2017 5. The ability to predict exacerbations was similar between the two classifications, with GOLD B 2017 exacerbating 17% more than GOLD B 2011 5.