10.1111/(ISSN)1468-1331 ENE European Journal of Neurology Eur J Neurol 1351-5101 1468-1331 10.1111/ene.15411 ENE15411 EJoN-22-0697.R1 ORIGINAL ARTICLE ORIGINAL ARTICLES Validation of new diagnostic criteria for fatigue in patients with Parkinson disease Fatigue diagnostic criteria in PD SICILIANO et al. Siciliano Mattia https://orcid.org/0000-0001-5246-2109 1 2 Kluger Benzi 3 De Micco Rosa https://orcid.org/0000-0002-6397-8888 rosita.demicco@gmail.com * 1 Chiorri Carlo 4 Sant'Elia Valeria 1 Silvestro Marcello 1 Giordano Alfonso 1 Tedeschi Gioacchino 1 Passamonti Luca 5 6 Trojano Luigi https://orcid.org/0000-0002-0328-9642 2 Tessitore Alessandro 1 Department of Advanced Medical and Surgical Sciences University of Campania "Luigi Vanvitelli" Naples Italy Department of Psychology University of Campania "Luigi Vanvitelli" Caserta Italy Departments of Neurology and Medicine University of Rochester Medical Center Rochester New York USA Department of Educational Sciences University of Genoa Genoa Italy Department of Clinical Neurosciences University of Cambridge Cambridge UK Institute of Molecular Bioimaging and Physiology National Research Council Milan Italy Correspondence Rosa De Micco, Department of Advanced Medical and Surgical Sciences, MRI Research Center Vanvitelli–FISM, University of Campania "Luigi Vanvitelli," Piazza Miraglia 2, 80138, Naples, Italy. Email: rosita.demicco@gmail.com 06 06 2022 02 05 2022 21 03 2022 12 05 2022 © 2022 European Federation of Neurological Societies © 2022 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology. 2022 © 2022 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology. http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. Abstract Background and purpose

Although disabling fatigue is common in Parkinson disease (PD), available consensus‐based diagnostic criteria have not yet been empirically validated. The aim of this study was to evaluate the clinimetric properties of the criteria.

 Methods

A sample of outpatients with PD was evaluated for demographic, clinical, behavioral, and cognitive features. Fatigue was diagnosed according to the new diagnostic criteria and was rated by means of the Parkinson Fatigue Scale (PFS) and Fatigue Severity Scale (FSS). Acceptability, concurrent and discriminant validity, and interrater reliability were evaluated with binary logistic regression analyses and Cohen kappa (κ).

 Results

Of 241 included patients, 17 (7.1%) met the diagnostic criteria for PD‐related fatigue. Eight of nine symptoms described in Section A of the diagnostic criteria occurred in >50% of patients with fatigue. Acceptability (missing data = 0.8%) of the criteria was good, as was their concurrent validity with the PFS (odds ratio = 3.65) and FSS (odds ratio = 3.63). The discriminant validity of fatigue criteria with other PD‐related behavioral and cognitive features was good (odds ratio < 1.68). The interrater reliability was excellent (κ = 0.92).

 Conclusions

This is the first study to test the clinimetric properties of case definition diagnostic criteria for PD‐related fatigue. Our results suggest that current diagnostic criteria may be useful in both clinical practice and research. Future longitudinal studies should examine their long‐term stability.

 fatigability fatigue nonmotor symptoms Parkinson disease validation