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.