Effect of mobility impairment categorized by Patient Determined Disease Steps and the NARCOMS Mobility Performance Scale on indirect and intangible costs#.

EQ-5D = EuroQol 5 Dimension, MS = Multiple Sclerosis, PDDS = Patient Determined Disease Steps (scores of 0–2 representing “no walking disability”, 3–5 as “mild-to-moderate” and 6–8 as “severe-to-total”), PS = Performance Scale, Q = question number, SD = standard deviation, WTP = willingness-to-pay.*No mobility impairment was used as referent,†P#Sample sizes for each scale varied due to survey completeness.