Fig. 2

Overview of the cluster analyses categorized in ABCD groups. The three different cluster analyses (resp. used variables: mMRC and exacerbation frequency, CAT and exacerbation frequency and Burgels eight clinical variables) are shown categorized in group A, B, C and D. The definition of the ABCD group in the reproduction phenotype is based on mMRC. Definition ABCD groups: Group ‘A’ includes patients with mMRC 0–1 or CAT < 10 and 0–1 exacerbation per year; group ‘B’ includes patients with mMRC ≥ 2 or CAT ≥ 10 and 0–1 exacerbation per year; group ‘C’ includes patients with ≥ 2 exacerbations or ≥ 1 exacerbation leading to hospital admission with mMRC 0–1 or CAT < 10 and group ‘D’ includes patients with ≥ 2 exacerbations or ≥ 1 exacerbation leading to hospital admission with mMRC ≥ 2 or CAT ≥ 10; mMRC: modified Medical Research Council; CAT: COPD Assessment Test