COPD keywords

chronic airflow obstruction* OR chronic airway obstruction* OR chronic bronchitis OR chronic lung disease OR chronic obstructive airway disease OR chronic obstructive bronchitis OR chronic obstructive bronchopulmonary disease OR chronic obstructive lung OR chronic obstructive pulmonary OR chronic obstructive respiratory OR chronic respiratory disease OR coad OR copd OR pulmonary emphysema OR obstructive lung disease OR obstructive respiratory disease OR obstructive respiratory tract disease