Which statement about COPD diagnosis and assessment is most accurate?

• A. Chest X-ray alone is diagnostic for COPD.
• B. Sputum culture is essential for COPD diagnosis.
• C. Spirometry demonstrating obstruction, supplemented by symptom questionnaires like mMRC or CAT, is central to assessment.
• D. ECG is diagnostic for COPD evaluation.

Answer: (C)

Spirometry showing persistent airflow obstruction is the diagnostic cornerstone for COPD, best demonstrated by post-bronchodilator testing with a reduced FEV1/FVC ratio (commonly below 0.70). Once obstruction is established, assessing symptoms and exacerbation risk guides management, with tools like the mMRC dyspnea scale or the COPD Assessment Test (CAT) helping quantify impact on daily life and classify patients for treatment decisions. A chest X-ray cannot diagnose COPD; it may show hyperinflation or other findings but cannot confirm obstructive physiology. Sputum culture isn’t needed to diagnose COPD and is reserved for suspected infection or specific clinical situations. An ECG isn’t a diagnostic tool for COPD either, though it can help evaluate potential cardiovascular comorbidity.