Cross-cultural adaptation and validation of the fatigue severity scale among kannada-speaking individuals with neurological disorders: A cross-sectional study in South India

Abstract

Purpose: The Fatigue Severity Scale (FSS) has been translated and validated in many languages across the world. Since it is a self-reported scale, it is necessary for clients to understand the components in order to quantify them. However, to date, the version in Kannada, the language spoken locally in the state of Karnataka in South India, has not been validated. This study aimed to perform cross-cultural adaptation and determine concurrent validity and test-retest reliability of the Kannada version FSS among Kannada-speaking individuals with neurological disorders. Method: A cross-sectional study was conducted in the neuro-rehabilitation unit of a tertiary care hospital in southern Karnataka. Cultural adaptation of the scale was targeted at the Kannada-speaking population. It was pilot tested among 30 individuals with neurological conditions. The adapted scale was then evaluated for concurrent validity along with the Visual Analogue Fatigue Scale, by correlating the scores of fatigue assessed by both the scales among 83 participants. Reassessment of fatigue was done on all the participants the following day, to determine the test-retest reliability of the Kannada-version FSS scale among individuals with neurological disorders. Results: The Kannada version of the Fatigue Severity Scale showed an excellent correlation with Visual Analogue Fatigue Scale scores (r = 0.71, p<0.001) and good intra class correlation coefficient (α=0.92) with reassessment scores.” The fatigue scores showed no significant difference (F=0.9, p=0.5) when compared across various neurological conditions.” Conclusion and Implications: The culturally-adapted Kannada version of the Fatigue Severity Scale has proved to be a valid and reliable tool to assess severity of fatigue among Kannada-speaking individuals with neurological disorders. It could therefore be used routinely as an efficient tool for the effective assessment and management of fatigue in clients with all types of neurological conditions.