Establishing the Test-Retest Reliability and Minimal Detectable Change of the Multiple Sclerosis Resiliency Scale

Abstract

ABSTRACT BACKGROUND The Multiple Sclerosis Resiliency Scale (MSRS) was designed to assess factors connected to resilience when facing MS-related challenges. Although the MSRS has demonstrated good internal consistency and construct validity, its test-retest reliability has yet to be established. Identifying the minimal detectable change (MDC) of the scale will also improve its utility as an outcome measure for resilience-based interventions. This study aimed to determine the test-retest reliability and MDC of the MSRS. METHODS Participants were 62 persons with MS who completed the MSRS twice, with a mean ± SD of 16.60 ± 3.97 days (range, 14–30 days) between assessments. Test-retest reliability was evaluated using a 2-way, random-effects, single-measurement intraclass correlation coefficient (ICC), with agreement between time 1 and time 2 visualized with a Bland-Altman plot. The MDC was calculated using the standard error of measurement with a 95% CI. RESULTS At time 1, the mean ± SD MSRS score was 77.19 ± 11.97 (range, 45.83–97.00); at time 2, the mean ± SD score was 76.38 ± 12.75 (range, 46–98). The MSRS total score had good test-retest reliability (ICC = 0.88), with the subscale ICCs ranging from 0.77 (MS Peer Support) to 0.93 (Spirituality). The MDC for the total score was 11.95. CONCLUSIONS These findings suggest that the MSRS has good test-retest reliability and that persons with MS with a difference of 12 points or more between assessments have experienced a reliable change. The results support the utility of the MSRS as a potential outcome measure for MS-related resilience.