Poor sensitivity of symptoms in early detection of COPD

The prevalence of chronic obstructive pulmonary disease (COPD) has been increasing. However, COPD is often underdiagnosed. The objective of this study was to determine how many outpatients had persistent airflow limitation and could be diagnosed as COPD by post-bronchodilator spirometry. We also evaluated whether the newly diagnosed patients had any symptoms. All outpatients with liver or general diseases over 40 years old who regularly visited to our hospital were tested for pulmonary function by spirometry. Patients with airflow limitation by the first screening spirometry had further examinations including post-bronchodilator spirometry and chest radiograph by pulmonary specialists. A total of 288 patients accepted a first spirometry. The most common chronic diseases of these patients were chronic hepatitis (33.7%), fatty liver (26.4%), liver cirrhosis (8.3%), diabetes (3.5%) and hypertension (3.1%). Approximately half of the patients had a smoking history. 44 of 288 patients (15.3%) showed airflow limitation by pre-bronchodilator spirometry. Of these, 8 patients did not show airflow limitation by a repeat pre-bronchodilator spirometry nor did 5 patients by post-bronchodilator spirometry. The rest were diagnosed as COPD (80.6%), asthma (16.1%) and bronchiectasis (3.2%). The prevalence of COPD was 8.7%. Approximately half of the patients (13/25, 52.0%) diagnosed as COPD had never complained of any respiratory symptoms. Because symptoms such as dyspnea on exertion, cough and sputum are less sensitive for the diagnosis of COPD, the propagation of spirometry in a general practice/setting should be recommended for establishing the diagnosis rate of COPD rather than relying on the presence of respiratory symptoms.