text: There were signiﬁcant but modest differences in mean 
  dyspnea levels across the 17 study sites (data not 
  shown), which are not explained by the risk factors we 
  accounted for in our study. This ﬁnding is not surprising 
  because some of the potential contributing factors 
  previously mentioned and other site-speciﬁc factors 
  The affective dimension of dyspnea can be captured 
  using additional questionnaires (eg, Multidimensional 
  Dyspnea Proﬁle, Dyspnea-12). Studies have explored the 
  use of the Multidimensional Dyspnea Proﬁle in 
  
  TABLE 7 ] Unadjusted and Adjusted Dyspnea Associations With Quality of Life (SF-36) 