Principle variables in 6-min walk related to a poor prognosis in patients affected by idiopathic pulmonary fibrosis

Value predictors of a poor prognosis
Distance m<250
SpO2 nadir %<88
HRR bpm<13
DSP %·m<200

SpO2: arterial oxygen saturation measured by pulse oximetry; HRR: heart rate recovery after 1 min following the test; DSP: distance saturation product, the product of the 6-min walk distance and the lowest registered SpO2.