Background Rates of mortality and readmission are high in patients hospitalised with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). In this population, the prognostic value of the Medical Research Council Dyspnoea Scale (MRCD) is uncertain, and an extended MRCD (eMRCD) scale has been proposed to improve its utility. Coexistent pneumonia is common and, although the CURB-65 prediction tool is used, its discriminatory value has not been reported.

Methods Clinical and demographic data were collected on consecutive patients hospitalised with AECOPD. The relationship of stable-state dyspnoea severity to in-hospital mortality and 28-day readmission was assessed. The discriminatory value of CURB-65, MRCD and eMRCD, in the prediction of in-hospital mortality, was assessed and compared.

Results 920 patients were recruited. 10.4% died in-hospital and 19.1% of the 824 survivors were readmitted within 28 days of discharge. During their stable state prior to admission, 34.2% of patients were too breathless to leave the house. Mortality was significantly higher in pneumonic than in non-pneumonic exacerbations (20.1% vs 5.8%, p<0.001). eMRCD was a significantly better discriminator than either CURB-65 or the traditional MRCD scale for predicting in-hospital mortality, and was a stronger prognostic tool than CURB-65 in the subgroup of patients with pneumonic AECOPD.

Conclusions The severity of dyspnoea in the stable state predicts important clinical outcomes in patients hospitalised with AECOPD. The eMRCD scale identifies a subgroup of patients at a particularly high risk of in-hospital mortality and is a better predictor of mortality risk than CURB-65 in exacerbations complicated by pneumonia.