What are the diagnostic criteria for Chronic Obstructive Pulmonary Disease (COPD)?

From the Guidelines

COPD should be diagnosed based on a post-bronchodilator FEV1/FVC ratio less than 0.7, as recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) report 1. The diagnosis of COPD should consider individuals with chronic respiratory symptoms and/or exposure to risk factors, such as cigarette or biomass smoke exposure. According to the GOLD report, forced spirometry demonstrating airflow obstruction after bronchodilation is required to confirm the diagnosis of COPD. The combination of clinical evaluation and spirometry reduces the potential for COPD overdiagnosis and overtreatment, which may occur if either step is omitted. Some key points to consider in the diagnosis and management of COPD include:

• The use of post-bronchodilator spirometry to confirm airflow obstruction that is not fully reversible 1
• The classification of COPD severity using the GOLD criteria, which considers FEV1 percentage of predicted value 1
• The evaluation of symptom burden using validated tools like the COPD Assessment Test (CAT) or Modified Medical Research Council (mMRC) dyspnea scale 1
• The importance of early diagnosis to allow for interventions like smoking cessation, which can significantly slow disease progression 1
• The need to exclude other conditions causing similar symptoms, such as asthma, bronchiectasis, heart failure, and tuberculosis 1

From the Research

COPD Diagnosis Criteria

• The diagnosis of chronic obstructive pulmonary disease (COPD) should be suspected in patients with risk factors, such as a history of smoking, who report dyspnea at rest or with exertion, chronic cough with or without sputum production, or a history of wheezing 2.
• COPD may be suspected based on findings from the history and physical examination, but must be confirmed by spirometry to detect airflow obstruction 3, 2.
• The current diagnostic criterion for airflow obstruction is a ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) < 70% 4.

Spirometry in COPD Diagnosis

• Spirometry is essential in the diagnosis of COPD, as it helps to detect airflow obstruction and assess the severity of the disease 3, 4.
• Screening spirometry is advocated and becomes feasible in the physician office setting with the availability of compact, relatively affordable apparatus that meets the appropriate technical specifications 4.
• Spirometry should be complemented by measurement of lung volumes using body plethysmography in those with evidence of airflow obstruction 4.

Clinical Predictors of COPD

• Findings that are most helpful to rule in COPD include a smoking history of more than 40 pack-years, a self-reported history of COPD, maximal laryngeal height, and age older than 45 years 2.
• The combination of three clinical variables-peak flow rate less than 350 L per minute, diminished breath sounds, and a smoking history of 30 pack-years or more-is another good clinical predictor, whereas the absence of all three of these signs essentially rules out airflow obstruction 2.