Figure 3. Discrimination between emphysema, bronchitis and asthma-associated COPD patients based on comorbidities using between-group principal component analysis (axes 1–2).

Hospitalization cases are displayed in the first 2 axes of the between-group PCA (smoothed blue colored density). The ellipsoids summarize the dispersion of the 3 COPD subtypes in the factorial map. Comorbidities are coded according to ICD-10 codes and depicted by framed labels. The number displayed on the upper left corner indicates the size of the grid.