Measuring fatigue in persons with spinal cord injury.

Abstract

To evaluate the psychometric properties of the Fatigue Severity Scale (FSS) in persons with spinal cord injury (SCI). A 2-week methodologic study was conducted to assess the internal consistency, reliability, and construct validity of the FSS. A tertiary spinal cord rehabilitation facility. 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. Not applicable. 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). 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 alpha=.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. The FSS has acceptable reliability with regard to internal consistency, test-retest reliability, and validity in persons with motor complete SCI.