Answers to open question “is there a sign or symptom you consider essential to define BE–COPD association”

Open questionAnswers nDetailed answers
Total responders29
Expectoration18Bronchorrhea, chronic sputum, chronic phlegm, phlegm production, purulent sputum
Recurrent infections11Frequent infections, frequent lower respiratory infections, more than one exacerbation per year, infections including pneumonia

Answers were grouped into three clusters according to similarity of answers. Detailed answers are listed in third column.