<http://schema.org/description>
"The six-minute walking distance test (6MWD), a test that measures a patient's ability to tolerate exercise and physical activity, is an effective tool for understanding disease severity in patients with chronic obstructive pulmonary disease (COPD), according to a three-year global study of patients with COPD sponsored by drug manufacturer GlaxoSmithKline."^^<http://www.w3.org/2001/XMLSchema#string>
<http://medicalxpress.com/news/2011-05-distance-accurate-indicator-disease-severity.html>