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

Recruiting

Brief Summary: 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.

Detailed Description: 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

Recruitment & Eligibility

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

Primary Outcome Measures

Name	Time	Method
Percentage of prevalence of Asthma COPD overlap among the asthma and COPD subjects.	3 years	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. (Assessment: % of subjects with ACO among patients with asthma and COPD respectively)

Secondary Outcome Measures

Name	Time	Method
Percentage of patient with treatment that is different from the guidelines recommendation	3 years	To evaluate the gap between guideline recommendations and real-world clinical practice in identifying COPD patients with asthma and asthma patients with COPD
The percentages of patients on various medications (e.g. inhaled steroid, LABA, LAMA)	3 years	To review the medications given to COPD patients with asthma and asthma patients with COPD compared to guideline recommendations
The pecentages of patients receiving different symptoms control assessments (e.g. use of Asthma control test, use of COPD assessment test)	3 years	To review the current practices of symptom control assessment
Percentages of subjects with morbidity (e.g. congestive heart failure)	3 years	To assess the 3 year morbidity of ACO patient compared to COPD and asthma patients.
Percentages of subjects with mortality	3 years	To assess the 3 year mortality of ACO patient compared to COPD and asthma
Percentages of patients with various Genetic markers	3 years	Genetic markers got differentiating ACO patients from patients with COPD or asthma