Construct validation of multiple sclerosis walking scale-12 scores among black individuals with multiple sclerosis: preliminary evidence.

BACKGROUND: The validity of inferences from 12-item Multiple Sclerosis Walking Scale (MSWS-12) scores has been established in homogeneous samples consisting largely of White people with multiple sclerosis (MS). There is evidence for differences in walking performance between Black and White people with MS, possibly explained by embodiment associated with structural racism and social determinants of health. The differences in walking performance might extend into perceptions of walking impairment as measured by the MSWS-12. PURPOSE: This study examined the construct validity of inferences from MSWS-12 scores as a patient-reported outcome measure (PROM) of walking impairment in Black people with MS. METHOD: The sample included 179 participants with MS who self-identified as either Black (n = 55) or White (n = 124). The participants completed the MSWS-12, Timed 25-Foot Walk (T25FW), Six-Minute Walk (6MW), Timed-Up-and-Go (TUG), Short Physical Performance Battery (SPPB), Brief International Cognitive Assessment for MS (BICAMS), Fatigue Severity Scale (FSS), Hospital Anxiety and Depression Scale (HADS), and 36-item Short-Form Survey (SF-36). The data analyses were performed using IBM SPSS. RESULTS: MSWS-12 scores had strong correlations with T25FW, 6MW, TUG, SPPB in the overall sample (|r's| of .72, .75, .65, & .67, respectively), and Black (|r's| of .63, .72, .65, & .65, respectively) and White (|r's| of .77, .78, .66, & .69, respectively) samples. The correlations were weak-to-moderate between MSWS-12 with BICAMS, FSS, and HADS. There was a pattern of strong associations between MSWS-12 scores with SF-36 physical scores (|r's| of .79, .80, & .79, respectively), yet weak correlations with mental scores (|r's| of .07, .00, & .08, respectively) for the overall, Black, and White samples. CONCLUSIONS: Our results provide preliminary support for the interpretation of MSWS-12 scores as a measure of walking impairment in clinical research and practice involving Black individuals with MS.