title: Psychometric properties of the Polish version of the Multidimensional Fatigue Inventory-20 in cancer patients.
abstract: BACKGROUND
  Multidimensional questionnaires estimating cancer-related fatigue (CRF) as a symptom cluster or a clinical syndrome primarily have been used and validated in English-speaking populations. However, cultural issues and language peculiarities can affect CRF assessment
  
  
  OBJECTIVE
  The main aims of this study were to evaluate the psychometric properties of the Polish version of the Multidimensional Fatigue Inventory-20 (MFI-20) and to deliver to clinicians a multidimensional tool for CRF assessment in Polish-speaking patients with cancer.
  
  
  METHODS
  After forward-backward translation procedures, the Polish version of MFI-20 was administered to 340 cancer patients. The Polish MFI-20 was appraised in terms of acceptability, reliability, and validity. Internal consistency was assessed by calculating Cronbach's alpha coefficients. Structural validity was evaluated with confirmatory factor analysis.
  
  
  RESULTS
  The translated MFI-20 was well accepted; 90% of subjects fully completed the questionnaire. The overall Cronbach's alpha coefficient was 0.9, ranging from 0.57 to 0.81. All correlation coefficients among Numeric Rating Scale-fatigue, fatigue-related items from the European Organization for Research and Treatment of Cancer Quality of Life Core-30 questionnaire, and the MFI--20 were statistically significant (P < 0.001). Confirmatory factor analysis demonstrated good structural validity and revealed only three dimensions in the Polish version of the MFI-20-physical and mental fatigue as well as reduced motivation.
  
  
  CONCLUSIONS
  The Polish version of the MFI-20 is well accepted by patients, reliable, and a valid instrument to assess CRF in Polish cancer patients.
authors.affiliation: Department of Palliative Medicine, Medical University of Gdańsk, Poland. Electronic address: tomaszbuss@gumed.edu.pl.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Buss
authors.affiliation: Department of Surgical Nursing, Medical University of Gdańsk, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kruk
authors.affiliation: Department of Endocrinology and Internal Medicine, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Wiśniewski
authors.affiliation: Department of Palliative Medicine, Medical University of Gdańsk, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Modlinska
authors.affiliation: Department of Palliative Medicine, Medical University of Gdańsk, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Janiszewska
authors.affiliation: Department of Palliative Medicine, Medical University of Gdańsk, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Lichodziejewska-Niemierko
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005221:Fatigue / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000175:diagnosis*; D009483:Neuropsychological Tests; D011044:Poland; D011594:Psychometrics / Q000379:methods / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards*; D014175:Translating; D055815:Young Adult
keywords: Fatigue; Multidimensional Fatigue Inventory; cancer; reliability; validity