Small changes in six-minute walk distance are important in diffuse parenchymal lung disease

SummaryThe aim of this study was to determine the minimal important difference for the six-minute walk distance in people with diffuse parenchymal lung disease.MethodsForty-eight subjects (24 idiopathic pulmonary fibrosis) undertook the six-minute walk test before and after an 8-week exercise program. The minimal important difference was calculated using a distribution-based and an anchor-based method. A global rating of change scale was used as the external criterion to judge patients as clinically unchanged or changed.ResultsThe mean change in six-minute walk distance in improved subjects was 50.0m, compared to 4.0m in unchanged subjects and a reduction of 64.3m in those classified as worse (p