Clinical importance of steps taken per day among persons with multiple sclerosis

PLoS One. 2013 Sep 4;8(9):e73247. doi: 10.1371/journal.pone.0073247. eCollection 2013.

Abstract

Background: The number of steps taken per day (steps/day) provides a reliable and valid outcome of free-living walking behavior in persons with multiple sclerosis (MS).

Objective: This study examined the clinical meaningfulness of steps/day using the minimal clinically important difference (MCID) value across stages representing the developing impact of MS.

Methods: This study was a secondary analysis of de-identified data from 15 investigations totaling 786 persons with MS and 157 healthy controls. All participants provided demographic information and wore an accelerometer or pedometer during the waking hours of a 7-day period. Those with MS further provided real-life, health, and clinical information and completed the Multiple Sclerosis Walking Scale-12 (MSWS-12) and Patient Determined Disease Steps (PDDS) scale. MCID estimates were based on regression analyses and analysis of variance for between group differences.

Results: The mean MCID from self-report scales that capture subtle changes in ambulation (1-point change in PDSS scores and 10-point change in MSWS-12 scores) was 779 steps/day (14% of mean score for MS sample); the mean MCID for clinical/health outcomes (MS type, duration, weight status) was 1,455 steps/day (26% of mean score for MS sample); real-life anchors (unemployment, divorce, assistive device use) resulted in a mean MCID of 2,580 steps/day (45% of mean score for MS sample); and the MCID for the cumulative impact of MS (MS vs. control) was 2,747 steps/day (48% of mean score for MS sample).

Conclusion: The change in motion sensor output of ~800 steps/day appears to represent a lower-bound estimate of clinically meaningful change in free-living walking behavior in interventions of MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Case-Control Studies
  • Disease Progression
  • Female
  • Humans
  • Male
  • Middle Aged
  • Multiple Sclerosis / diagnosis
  • Multiple Sclerosis / physiopathology*
  • Regression Analysis
  • Time Factors
  • Walking*

Grant support

This research was supported by an investigator-initiated grant from Acorda Therapeutics. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The funders did receive and read a copy of the paper and provided approval before submission.