Fig. 14:  Dyspnea not only affects the quality of life, it also appears to affect the quantity of life.  Two graphics show this comparison.^[9]  A study published in 2002 looked at three stages of COPD, based on the FEV₁ (an older categorization of COPD severity), and showed little difference between stages 1, 2, and 3, based on FEV₁ severity.  However, when looking at dyspnea (the grading system in the Figure is a bit different from the MRC scale), it can be seen that the patients who only have dyspnea with hurrying were much less likely to die over 5+ years than the ones who are too dyspneic to leave the house.  So dyspnea is certainly associated with an increased mortality risk.  Whether it is causal or just an epiphenomenon remains to be determined, but this Figure nicely illustrates that knowing the level of severity of dyspnea in a patient allows the physician to be able to make some sort of prognostication.