Walking speed and economic outcomes for walking-impaired patients with multiple sclerosis.

This article estimates the impact of walking speed (measured using the Timed 25-Foot Walk [T25FW]) on three economic outcomes: productivity (annual earnings), care burden (value per year) and quality of life (utility score). Empirical data are not available to directly measure these relationships. Therefore, this article develops indirect estimates by characterizing the impact of the T25FW on the Expanded Disability Status Scale (EDSS), and the impact of the EDSS on economic outcomes. Use of the EDSS as a bridge introduces uncertainty, which precludes robust quantification of the relationship between walking speed and economic outcomes. Nonetheless, the analysis provides plausible ranges for the magnitude of these relationships.