Additional file 2: of A meta-analysis of four randomized clinical trials to confirm the reliability and responsiveness of the Shortness of Breath with Daily Activities (SOBDA) questionnaire in chronic obstructive pulmonary disease

Schematic of the study design used in each of the four included studies. *Studies DB2113361 [11] and DB2113373 [13]. †Studies DB2113360 (Study 1) and DB2113374 (Study 2) [12]. Baseline SOBDA score refers to data collected during the 7 days prior to V2. SOBDA, Shortness of Breath with Daily Activities; V, visit. (PDF 990 kb)