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Objective: This quasi-experimental study was conducted to determine whether differences existed in the total distance walked and energy expended between two conditions of administering the 6-Minute Walk test (6MW) across different levels of disability in people with multiple sclerosis (MS). Methods: The sample comprised 160 individuals with MS. One group of participants (n = 82) completed a 6MW while wearing a portable metabolic unit (K4b2, Cosmed, Italy) in a square hallway with four corridors and performing 90° turns. Another group (n = 78) completed a 6MW while wearing the same metabolic unit in a single corridor and performing 180° turns. Main outcome measures included total distance walked (in feet) and oxygen consumption (in milliliters per minute) expressed as 30-second averages for 1 minute before the 6MW and over the entire 6MW. Disability status was assessed using the Patient-Determined Disease Steps scale. Results: Participants undertaking the 6MW in a single corridor (1412 ft) walked 37 ft (2.7%) farther than those undertaking the test in a square hallway (1375 ft), but this difference was not statistically significant (F = 0.45, P = .51). Those completing the 6MW in a single corridor expended more energy than those completing the 6MW in the square hallway with four corridors (F = 3.41, P < .01). Conclusions: Either protocol is acceptable, but researchers should be aware of the additional physiological demands when administering the 6MW in a single corridor with 180° turns.

Introduction There has been increased interest in the objective monitoring of free-living walking behavior using accelerometers in clinical research involving persons with multiple sclerosis (MS). The current investigation examined and compared the accuracy of the StepWatch activity monitor and ActiGraph model GT3X+ accelerometer for capturing steps taken during various speeds of prolonged, over-ground ambulation in persons with MS who had mild, moderate, and severe disability. Methods Sixty-three persons with MS underwent a neurological examination for generation of an EDSS score and undertook two trials of walking on the GAITRite electronic walkway. Participants were fitted with accelerometers, and undertook three modified six-minute walk (6MW) tests that were interspersed with 10–15 minutes of rest. The first 6MW was undertaken at a comfortable walking speed (CWS), and the two remaining 6MW tests were undertaken above (faster walking speed; FWS) or below (slower walking speed; SWS) the participant's CWS. The actual number of steps taken was counted through direct observation using hand-tally counters. Results The StepWatch activity monitor (99.8%–99.9%) and ActiGraph model GT3X+ accelerometer (95.6%–97.4%) both demonstrated highly accurate measurement of steps taken under CWS and FWS conditions. The StepWatch had better accuracy (99.0%) than the ActiGraph (95.5%) in the overall sample under the SWS condition, and this was particularly apparent in those with severe disability (StepWatch: 95.7%; ActiGraph: 87.3%). The inaccuracy in measurement for the ActiGraph was associated with alterations of gait (e.g., slower gait velocity, shorter step length, wider base of support). Conclusions This research will help inform the choice of accelerometer to be adopted in clinical trials of MS wherein the monitoring of free-living walking behavior is of particular value.

Background and Objective: Minimal clinically important difference (MCID) values of 4 and 6 points have been proposed for interpreting meaningful change in Multiple Sclerosis Walking Scale-12 (MSWS-12) scores. This study examined the validity of those MCID values based on capturing corresponding changes in other walking outcomes in persons with multiple sclerosis (MS). Methods: On 2 occasions separated by 6 months, 82 persons with MS completed the MSWS-12, timed 25-ft walk (T25FW), 6-min walk (6MW), and gait analysis, and then wore an accelerometer over a 7-day period. We generated change scores for the MSWS-12 and formed groups of stable, worsened, and improved perceived walking based on both 4- and 6-point changes. The groups were compared for corresponding changes in other walking measures over time using mixed-model ANOVAs. Results: The mixed-model ANOVAs did not identify statistically significant group-by-time interactions on the T25FW (p = 0.98 and p = 0.67), the 6MW (p = 0.89 and p = 0.72), gait (p = 0.54 and p = 0.21), or accelerometry (p = 0.40 and p = 0.68) for MCID values of 4- or 6-point changes in MSWS-12 scores. Conclusions: We did not confirm that MCID values of 4 and 6 points for the MSWS-12 correspond with changes in performance, gait, and free-living assessments of walking in MS.

Objective: This quasi-experimental study was conducted to determine whether differences existed in the total distance walked and energy expended between two conditions of administering the 6-Minute Walk test (6MW) across different levels of disability in people with multiple sclerosis (MS). Methods: The sample comprised 160 individuals with MS. One group of participants (n = 82) completed a 6MW while wearing a portable metabolic unit (K4b2, Cosmed, Italy) in a square hallway with four corridors and performing 90° turns. Another group (n = 78) completed a 6MW while wearing the same metabolic unit in a single corridor and performing 180° turns. Main outcome measures included total distance walked (in feet) and oxygen consumption (in milliliters per minute) expressed as 30-second averages for 1 minute before the 6MW and over the entire 6MW. Disability status was assessed using the Patient-Determined Disease Steps scale. Results: Participants undertaking the 6MW in a single corridor (1412 ft) walked 37 ft (2.7%) farther than those undertaking the test in a square hallway (1375 ft), but this difference was not statistically significant (F = 0.45, P = .51). Those completing the 6MW in a single corridor expended more energy than those completing the 6MW in the square hallway with four corridors (F = 3.41, P < .01). Conclusions: Either protocol is acceptable, but researchers should be aware of the additional physiological demands when administering the 6MW in a single corridor with 180° turns.

Introduction There has been increased interest in the objective monitoring of free-living walking behavior using accelerometers in clinical research involving persons with multiple sclerosis (MS). The current investigation examined and compared the accuracy of the StepWatch activity monitor and ActiGraph model GT3X+ accelerometer for capturing steps taken during various speeds of prolonged, over-ground ambulation in persons with MS who had mild, moderate, and severe disability. Methods Sixty-three persons with MS underwent a neurological examination for generation of an EDSS score and undertook two trials of walking on the GAITRite electronic walkway. Participants were fitted with accelerometers, and undertook three modified six-minute walk (6MW) tests that were interspersed with 10–15 minutes of rest. The first 6MW was undertaken at a comfortable walking speed (CWS), and the two remaining 6MW tests were undertaken above (faster walking speed; FWS) or below (slower walking speed; SWS) the participant's CWS. The actual number of steps taken was counted through direct observation using hand-tally counters. Results The StepWatch activity monitor (99.8%–99.9%) and ActiGraph model GT3X+ accelerometer (95.6%–97.4%) both demonstrated highly accurate measurement of steps taken under CWS and FWS conditions. The StepWatch had better accuracy (99.0%) than the ActiGraph (95.5%) in the overall sample under the SWS condition, and this was particularly apparent in those with severe disability (StepWatch: 95.7%; ActiGraph: 87.3%). The inaccuracy in measurement for the ActiGraph was associated with alterations of gait (e.g., slower gait velocity, shorter step length, wider base of support). Conclusions This research will help inform the choice of accelerometer to be adopted in clinical trials of MS wherein the monitoring of free-living walking behavior is of particular value.

Background and Objective: Minimal clinically important difference (MCID) values of 4 and 6 points have been proposed for interpreting meaningful change in Multiple Sclerosis Walking Scale-12 (MSWS-12) scores. This study examined the validity of those MCID values based on capturing corresponding changes in other walking outcomes in persons with multiple sclerosis (MS). Methods: On 2 occasions separated by 6 months, 82 persons with MS completed the MSWS-12, timed 25-ft walk (T25FW), 6-min walk (6MW), and gait analysis, and then wore an accelerometer over a 7-day period. We generated change scores for the MSWS-12 and formed groups of stable, worsened, and improved perceived walking based on both 4- and 6-point changes. The groups were compared for corresponding changes in other walking measures over time using mixed-model ANOVAs. Results: The mixed-model ANOVAs did not identify statistically significant group-by-time interactions on the T25FW (p = 0.98 and p = 0.67), the 6MW (p = 0.89 and p = 0.72), gait (p = 0.54 and p = 0.21), or accelerometry (p = 0.40 and p = 0.68) for MCID values of 4- or 6-point changes in MSWS-12 scores. Conclusions: We did not confirm that MCID values of 4 and 6 points for the MSWS-12 correspond with changes in performance, gait, and free-living assessments of walking in MS.

Objective Fatigue is one of the most common, debilitating and life altering symptoms experienced by those with multiple sclerosis (MS) and has become the focus of therapeutic interventions and clinical rehabilitation. There is limited evidence regarding the psychometric properties and clinical relevance of fatigue outcomes for interpreting the effectiveness of intervention and rehabilitation strategies. This study determined the reliability, precision and clinically important change of the uni-dimensional Fatigue Severity Scale (FSS) and the multi-dimensional Modified Fatigue Impact Scale (MFIS). Methods The FSS and MFIS along with physical, psychological and cognitive clinical outcomes were administered to a sample of 82 persons with MS in a clinical research setting on two time points, separated by six months. Intraclass correlation coefficient (ICC) analyses established reliability; standard error of measurement (SEM) and coefficient of variation (CV) determined precision; minimal detectable change (MDC) defined clinically important change. Results Participants varied in type of MS and disability status, with 77% of participants classified as having substantial fatigue, based on the criteria of a mean FSS score ≥ 4. The MFIS (ICC = 0.863) and the FSS (ICC = 0.751) had acceptable reliability over six months. Precision was reasonable for both scales (based on SEM and CV estimates) but better for the FSS. MDC estimates were established and were lower for the FSS. Conclusion Reliability of the FSS and MFIS falls within acceptable ranges, and precision and clinically important change estimates provide guidelines for interpreting change in scores from these outcomes in clinical research of intervention and rehabilitation approaches for managing fatigue.

Objective Fatigue is one of the most common, debilitating and life altering symptoms experienced by those with multiple sclerosis (MS) and has become the focus of therapeutic interventions and clinical rehabilitation. There is limited evidence regarding the psychometric properties and clinical relevance of fatigue outcomes for interpreting the effectiveness of intervention and rehabilitation strategies. This study determined the reliability, precision and clinically important change of the uni-dimensional Fatigue Severity Scale (FSS) and the multi-dimensional Modified Fatigue Impact Scale (MFIS). Methods The FSS and MFIS along with physical, psychological and cognitive clinical outcomes were administered to a sample of 82 persons with MS in a clinical research setting on two time points, separated by six months. Intraclass correlation coefficient (ICC) analyses established reliability; standard error of measurement (SEM) and coefficient of variation (CV) determined precision; minimal detectable change (MDC) defined clinically important change. Results Participants varied in type of MS and disability status, with 77% of participants classified as having substantial fatigue, based on the criteria of a mean FSS score ≥ 4. The MFIS (ICC = 0.863) and the FSS (ICC = 0.751) had acceptable reliability over six months. Precision was reasonable for both scales (based on SEM and CV estimates) but better for the FSS. MDC estimates were established and were lower for the FSS. Conclusion Reliability of the FSS and MFIS falls within acceptable ranges, and precision and clinically important change estimates provide guidelines for interpreting change in scores from these outcomes in clinical research of intervention and rehabilitation approaches for managing fatigue.