text: All participants ﬁlled out the COPD Assessment Test 
  (CAT) questionnaire. Elevated CAT scores indicate a 
  greater burden of respiratory symptoms impacting 
  daily activities and health status.13 The St. George’s 
  Respiratory Questionnaire (SGRQ)14-16 was used to 
  assess respiratory disease-related quality of life. Higher 
  SGRQ scores indicate poorer health status. Both the 
  CAT and SGRQ questionnaires were completed prior  The composite dyspnea impact measure was scaled so its 
  minimum value was 0 if the response to each of the 15 
  questions was 0, and the maximum value was scaled to 
  100 if the individual responses for all 15 questions rep- 
  resented the most severe dyspnea response. 