Figure 2From: Health-related quality of life, utility, and productivity outcomes instruments: ease of completion by subjects with COPDSubjects' mean scoring according to severity of COPD (GOLD criteria: FEV1 % predicted normal values, ≥ 80% = Stage I mild, 50. – 79% = Stage IIA moderate, 40. – 49% = Stage IIB moderate, <30% = Stage III severe)Back to article page