Measuring Fatigue in Persons With Spinal Cord Injury

Abstract

Anton HA, Miller WC, Townson AF. Measuring fatigue in persons with spinal cord injury. Objective To evaluate the psychometric properties of the Fatigue Severity Scale (FSS) in persons with spinal cord injury (SCI). Design A 2-week methodologic study was conducted to assess the internal consistency, reliability, and construct validity of the FSS. Setting A tertiary spinal cord rehabilitation facility. Participants Forty-eight community-living subjects at least 1 year post-SCI with American Spinal Injury Association (ASIA) grade A or B SCI and no medical conditions causing fatigue. The sample was predominantly male (n=31 [65%]) with tetraplegia (n=26 [54%]) and ASIA grade A injuries (n=30 [63%]). The average duration since injury was 14.9 years. Interventions Not applicable. Main Outcome Measures The ASIA Impairment Scale, the FSS, a visual analog scale for fatigue (VAS-F), the vitality scale of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and the Center for Epidemiologic Studies Depression Scale (CES-D). Results Mean FSS score ± standard deviation at baseline was 4.4±1.4, with 54% (n=26) scoring greater than 4. The internal consistency of the FSS was excellent (Cronbach α=.89). Two-week test-retest reliability was adequate (intraclass correlation coefficient, .84; 95% confidence interval, .74–.90). The magnitude of the relationship was as hypothesized for the VAS-F ( r=.67) and CES-D ( r=.58) and lower than hypothesized for the vitality subscore ( r=−.48) of the SF-36. Conclusions The FSS has acceptable reliability with regard to internal consistency, test-retest reliability, and validity in persons with motor complete SCI.