The Parkinson fatigue scale: an evaluation of its validity and reliability in Greek Parkinson’s disease patients

Abstract

Objective

Fatigue is one of the most frequent and important nonmotor symptoms of patients with Parkinson disease (PD), affecting quality of life. Although, in some cases, it may be a severe and debilitating complaint, it remains relatively unexplored. The PFS-16 is a fatigue measure, specifically designed for PD patients. The aim of this study was to investigate the psychometric properties of Parkinson fatigue scale (PFS-16) in Greek PD patients.

Methods

In total, 99 patients with PD were assessed. The following psychometric properties were tested: data quality, floor/ceiling effects, reliability (internal consistency, test–retest reliability), and construct validity. Construct validity was evaluated by examining correlations with other variables including other fatigue measures such as Fatigue Severity Scale (FSS) and the vitality scale (SF-VT) of SF-36. Moreover, assumptions were explored about "known" groups concerning fatigue.

Results

The mean score for the PFS-16 was 2.95 (± 0.91); acceptability was good with negligible floor and ceiling effects. Results showed high internal consistency (Cronbach's alpha, 0.96) and test–retest reliability (ICC, 0.93). Strong correlations were observed between the PFS-16 and other fatigue (FFS and SF-VT) measures (rs = 0.77 and − 0.70, p < 0.001), revealing appropriate validity. Furthermore, predictions for "known" groups validity were verified.

Conclusion

The Greek version of the PFS-16 showed satisfactory reliability and validity and thus can be regarded as a useful tool in assessing fatigue in PD.

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