# Validity and Reliability of the Fatigue Severity Scale in an Adult Swedish Burn Population

## TL;DR

The study shows that the Fatigue Severity Scale is a reliable and valid tool for measuring fatigue in adult Swedish burn patients.

## Contribution

The study validates the FSS for use in a specific Swedish burn population, confirming its reliability and concurrent validity.

## Key findings

- The FSS showed high internal consistency with Cronbach’s alpha of 0.96 at both 6 and 12 months.
- The FSS demonstrated strong concurrent validity with the BFI, with Spearman’s rho of 0.816 and 0.863 at two timepoints.

## Abstract

What are the main findings?
The Fatigue Severity Scale (FSS) demonstrates a high concurrent validity compared to the Brief Fatigue Inventory (BFI).A high internal consistency was found (α >
0.9) for all items in both FSS and BFI.

The Fatigue Severity Scale (FSS) demonstrates a high concurrent validity compared to the Brief Fatigue Inventory (BFI).

A high internal consistency was found (α >
0.9) for all items in both FSS and BFI.

What are the implications of the main findings?
The FSS will be a useful tool in connection with clinical follow-ups at the Burn Center in Uppsala.

The FSS will be a useful tool in connection with clinical follow-ups at the Burn Center in Uppsala.

Background: A burn injury is a complex trauma often followed by complications, one of which is fatigue. The objective of this study was to validate the Fatigue Severity Scale (FSS) in an adult Swedish burn cohort. Methods: A prospective cohort study was performed at the Burn Center at Uppsala University Hospital in Uppsala, Sweden. All patients who were registered for follow-up 6 months after their burn injury were asked to participate. Included patients completed questionnaires at 6 and 12 months postburn. Psychometric properties were investigated, including internal consistency (Cronbach’s alpha) and concurrent validity, comparing FSS with the Brief Fatigue Inventory (BFI), which was considered to be the “gold standard.” Convergent validity was investigated among the fatigue assessments and quality of life, depression/anxiety, and daily activities. Results: In total, 70 included patients attended both visits. FSS demonstrated high internal consistency (Cronbach’s alpha: 0.96 at both timepoints). There was high concurrent validity between FSS and BFI on both occasions (Spearman’s rho: 0.816 and 0.863, respectively), and the convergent validity was strong. Conclusions: The result indicates that the two fatigue scales correspond well to each other and that the FSS, therefore, is a valid and reliable assessment of fatigue in adult Swedish burn patients.