Principle variables in 6-min walk test related to a poor prognosis in patients affected by COPD

Value predictors of a poor prognosis
Distance m≤334
6MWspeed m·s−1≤0.8
6MWW m·kg−1≤20 000
DSP %·m≤290

6MWspeed: calculated by dividing the 6-min walk distance by the total walking time; 6MWW: 6-min walking work, the product of the 6-min walking distance and the patient weight; DSP: distance saturation product, the product of the 6-min walk distance and the lowest registered arterial oxygen saturation measured by pulse oximetry.