Fig. 10:  Finally this Figure illustrates the latest four-group Global Obstructive Lung Disease COPD rating scale,^[6] which is commonly employed in various gradings and rankings.  This scale defines 4 categories of disease, groups A, B, C, and D, using two major variables to assign patients into one of these 4 categories: 

• the number of exacerbations per year or
• the risk of exacerbations, as determined by spirometry;
• the impact of the disease on the patient, assessed with the Modified MRC questionnaire, which goes from 0 to 4 in this case, or
• the COPD assessment test, which assesses the effect of the disease on the patient’s quality of life.  

In sum, dyspnea is now included in several COPD staging schemas, which emphasizes the importance of dyspnea in assessing the severity of the disease.