Productive cough associated with patient-reported outcomes and computed tomography analysis results in idiopathic pulmonary fibrosis: a single centre cross-sectional study

Comparison of a) St George's Respiratory Questionnaire (SGRQ), b) Leicester Cough Questionnaire (LCQ), c) the Cough and Sputum Assessment Questionnaire (CASA-Q), and d) normally attenuated lung volume as a percentage of the whole lung volume (NLs%) among non-cough, dry cough, and productive cough groups of patients with idiopathic pulmonary fibrosis.