text: STUDY DESIGN AND METHODS: This population-based study included 2,857 adults who were 
  experiencing respiratory symptoms. These individuals had not been previously diagnosed 
  with any lung conditions and were recruited from 17 Canadian centers using random digit 
  dialing. Each participant underwent spirometry testing both before and after using a bron- 
  chodilator to determine if they met the diagnostic criteria for COPD, asthma, or preserved 
  ratio impaired spirometry (PRISm), or if their spirometry results were normal. An age- 
  matched control group (n ¼ 231) was similarly recruited using random digit dialing. A 
  dyspnea impact assessment score from 0 to 100 was produced using questions from the 
  COPD Assessment Test and St. George’s Respiratory questionnaire. 
  RESULTS: Individuals with PRISm (n ¼ 172) reported more impactful dyspnea (mean score, 
  63.0; 95% CI, 59.5-66.4) than those with undiagnosed asthma (n ¼ 265; mean score, 56.6; 
  95% CI, 53.9-59.3) or undiagnosed COPD (n ¼ 330; mean score, 57.5; 95% CI, 55.1-59.9). All 
  groups reported signiﬁcantly more impactful dyspnea than the control group (mean score, 
  13.8; 95% CI, 11.8-15.7). Patient-speciﬁc risk factors including age, sex, BMI, smoking, and 
  comorbidities explained 20.6% of the variation in dyspnea. An additional 12.4% of the 
  variation was explained by disease classiﬁcation and another 1.7% by the severity of lung 
  function impairment assessed with spirometry. After adjusting for age, sex, and BMI, greater 
  dyspnea impact was associated with increased health care utilization, lower quality of life, and 
  reduced work productivity. 
  INTERPRETATION: Our ﬁndings showed that in community-based adults with undiagnosed 
  respiratory symptoms, those identiﬁed with PRISm experienced the greatest impact of dys- 
  pnea. Dyspnea imposes burdens on the health care system and is associated with impaired 
  quality of life and work productivity. 
  CHEST 2024; 166(6):1296-1308 