Fig. 6

Relative six-minute walk test (6MWT) minimal clinically important difference (MCID) using distribution-based methods. Sources: 1 & 2 = du Bois, 2010 [29] and du Bois, 2011 [30]; 3 = Swigris, 2010 [31]; 4 = Holland, 2009 [44]; 5 = Holland, 2010 [43]; 7 = Puhan, 2008 [51]; 8 = Puhan, 2011 [44]; 10 = Wise, 2005 [52]; 11 = Lee, 2014 [46]; 15 = Mathai, 2012 [49]; 17 = McDonald, 2013 [54]; 18 = Kwok, 2013 [50]. The green, red, blue, and orange bars represent studies conducted in patients with respiratory, cardiovascular, muscular, and other (i.e., frail elderly) diseases, respectively. COPD: chronic obstructive pulmonary disease; IPF: idiopathic pulmonary fibrosis; PAH: pulmonary arterial hypertension