Should we measure dyspnoea in everyone?

Abstract

The paper by Nielsen et al in this journal reports the prevalence of dyspnea in 15 countries throughout the world as 27%. Dyspnea is a powerfully aversive sensation frequently overlooked despite its prevalence and the severity of distress it causes. Despite its ‘subjective’ nature, dyspnea is a powerful predictor of morbidity and mortality. We suggest that this is because the information provided by enteroceptors is so rich that it is as valuable as the more precise but relatively sparse information provided by clinical tests. Relatively simple measures of dyspnea, such as the Medical Research Council Breathlessness Scale used by Nielsen et al, can provide meaningful information at very little cost.

The left panel shows 5-year mortality rates of patients classified by pulmonary function test according to the ATS guidelines: Stage I, FEV₁ > 50% of predicted; Stage II FEV₁ = 35 to 49% of predicted; and Stage III, FEV < 35% of predicted. The right panel shows 5-year mortality of patients classified by dyspnea grade as measured with the Medical Research Council Breathlessness Scale (MRC): Grade II (short of breath when hurrying on the level or walking up a slight hill); Grade III (have to walk slower than most people on the level); Grade IV (have to stop for breath after walking about 100 yards (or after a few minutes) on the level); Grade V (too breathless to leave the house, or breathless after undressing). Data from Nishimura et al [19].