Epidemiological studies indicate that patients with asthma–COPD overlap constitute about 1/3 of patients with obstructive airway diseases. However, in daily practice the coexistence of asthma and COPD does not seem to be diagnosed often. What are the possible reasons for this discrepancy?
If a patient enters a screening program and the first computed tomography (CT) is negative, how often are CT scans usually repeated in those with no pulmonary nodules? Is it necessary to repeat the CT scan if the first screening was negative?