text: Dyspnea regressed on lung function variables representing severity of impairment, after removing contributions of patient-speciﬁc factors and spirometry 
  disease group Tables 4 and 5 (1.7% of variability explained). Boldface indicates statitistical signiﬁcance. BD ¼ bronchodilator; PRISm ¼ preserved ratio 
  impaired spirometry. 