Figure 1From: Correlating changes in lung function with patient outcomes in chronic obstructive pulmonary disease: a pooled analysisOutcome means in ΔFEV 1 categories versus category midpoint value. Plots show data with Loess smooth curves superimposed. ΔFEV1, change from baseline in trough forced expiratory volume in 1 second; TDI, Transition Dyspnoea Index; ΔSGRQ, change from baseline in St George's Respiratory Questionnaire.Back to article page