Fig. 2
From: Measuring disease activity in COPD: is clinically important deterioration the answer?
Exacerbations versus composite CID in measuring meaningful disease progression at 3-years in TORCH [48]. a33% of the ITT were exacerbation positive in the first 6 months; b54% of the ITT were CID positive in the first 6 months. CID, clinically important deterioration; FEV1, forced expiratory volume in 1 s; ITT, intent-to-treat; SGRQ, St George’s Respiratory Questionnaire