Virgil Mathiowetz1. 1. Program in Occupational Therapy, Department of Physical Medicine & Rehabilitation, University of Minnesota, MMC 388, 420 Delaware Street SE, Minneapolis, Minnesota 55455, USA. mathi003@umn.edu
Abstract
OBJECTIVE: The test-retest reliability and the convergent validity of the Fatigue Impact Scale (FIS) were evaluated using secondary data from 54 persons with multiple sclerosis (MS). METHODS: This reliability and validity study used FIS data from before and after two control periods to evaluate test-retest reliability. Convergent validity of the FIS with the Fatigue Severity Scale and with subscales of the SF-36 Health Survey was evaluated using data collected before the first control period. RESULTS: No significant differences between before and after FIS measurements and intraclass correlation coefficients ranging from .68 to .85 indicate that the FIS has good test-retest reliability except for the physical subscale. The expected moderate correlations between the FIS and several subscales of the SF-36 support its convergent validity. In contrast, the unexpected low correlation between the FIS and Fatigue Severity Scale does not support convergent validity. CONCLUSION: The FIS has adequate reliability and validity and is recommended to evaluate the effectiveness of fatigue management interventions such as energy conservation education for persons with MS.
OBJECTIVE: The test-retest reliability and the convergent validity of the Fatigue Impact Scale (FIS) were evaluated using secondary data from 54 persons with multiple sclerosis (MS). METHODS: This reliability and validity study used FIS data from before and after two control periods to evaluate test-retest reliability. Convergent validity of the FIS with the Fatigue Severity Scale and with subscales of the SF-36 Health Survey was evaluated using data collected before the first control period. RESULTS: No significant differences between before and after FIS measurements and intraclass correlation coefficients ranging from .68 to .85 indicate that the FIS has good test-retest reliability except for the physical subscale. The expected moderate correlations between the FIS and several subscales of the SF-36 support its convergent validity. In contrast, the unexpected low correlation between the FIS and Fatigue Severity Scale does not support convergent validity. CONCLUSION: The FIS has adequate reliability and validity and is recommended to evaluate the effectiveness of fatigue management interventions such as energy conservation education for persons with MS.
Authors: Regina Rendas-Baum; Min Yang; Francoise Cattelin; Gene V Wallenstein; John D Fisk Journal: Qual Life Res Date: 2010-07-10 Impact factor: 4.147
Authors: Roy G Elbers; Marc B Rietberg; Erwin E H van Wegen; John Verhoef; Sharon F Kramer; Caroline B Terwee; Gert Kwakkel Journal: Qual Life Res Date: 2011-10-20 Impact factor: 4.147