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

 Subjects must fulfil all of the following criteria:

 -  All patients with confirmed diagnosis of COPD (post-bronchodilator FEV1/FVC<0.7 based
 on the medical records) 1 or asthma (defined as those with a consistent history and
 prior documented evidence of variable airflow obstruction, with evidence of an
 increase in FEV1 greater than 12% or 400 mL following bronchodilator or bronchial
 hyperresponsiveness on bronchial provocation testing, when stable) 6

 -  Aged >40 years old

 -  Signed written informed consent to participate in the study

 Exclusion Criteria:

 -  Patients currently with acute exacerbation of COPD by GOLD definition (any worsening
 of a patient's respiratory symptoms that is beyond normal day-to-day variations and
 requires a change in medication) 1 or acute exacerbation of asthma by GINA guideline.
 6

 -  Patients with respiratory diseases that can show similar symptoms to chronic airway
 diseases such as bronchiectasis, tuberculosis (TB)-destroyed lung parenchyma,
 endobronchial TB, and lung cancer, or those who have history of these diseases based
 on physician's judgment

 -  Patients currently diagnosed with pneumonia and acute bronchitis

 -  Patients currently randomized in other clinical studies