Clinical Characteristics of Asthma and COPD Overlap for Patients With Asthma and COPD in Hong Kong

This study is to assess the prevalence of Asthma COPD Overlap in subjects with diagnosed asthma and chronic obstructive pulmonary disease (COPD). The subsequent morbidity and mortality of subjects will be followed up for 3 years.

Rationale: Around 15 to 20% of COPD patients have features of asthma. These patients have more frequent and more severe exacerbations, and higher medical utilization. The Global Initiative for Asthma (GINA) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines have given joint recommendations on the identification, diagnosis and treatment of these patients having Asthma-COPD Overlap (ACO). These are at present expert opinions and further studies are needed to establish the optimal definitions and treatment options. The recommendations proposed by the guidelines have been adapted for use in the Asia area countries. Nonetheless, the application to clinical practice has not been well established and there are no prevalence data available on the COPD with asthma symptom population or asthma with COPD symptoms population based on the recommended features for identification. This is the current data gap in Asia. Primary objective: To determine the proportion and clinical characteristics of patients with ACO as defined by the joint GINA and GOLD recommendation amongst diagnosed COPD and asthma patients seen at the out-patient clinics