title: Validation of the Portuguese version of functional assessment of cancer therapy-fatigue (FACT-F) in Brazilian cancer patients.
abstract: OBJECTIVE
  The purpose of this study was to validate the Portuguese version of the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) in order to establish its assessment properties, including validity and reliability in a sample of Brazilian cancer patients.
  
  
  METHODS
  Two hundred seventy patients with different types of cancer were included for this study; the mean age was 50.5 years. The reliability was assessed by internal consistency and reproducibility. Construct validity was assessed through convergent validity and discriminant validity. Convergent validity was examined by comparing the FACT-F to the SF-36. Discriminant validity of the FACT-F evaluated the ability of the scale to differentiate defined groups, discriminating patients according to Eastern Cooperative Oncology Group Performance Status and different stages of disease.
  
  
  RESULTS
  FACT-F had high internal consistency (Cronbach alpha coefficient was 0.78 for physical well-being, 0.68 for social/family well-being, 0.75 for emotional well-being, 0.74 for functional well-being, 0.91 for fatigue, and 0.92 for total FACT-F). The range of test-retest intraclass correlation was from 0.72 to 0.91 (p < 0.0001). The Pearson product correlation revealed good correlations between the total FACT-F and subscales of the SF-36 in most dimensions, ranging from r = 0.51 to r = 0.76, except for SF-36 physical (r = 0.31). The positive correlations between the SF-36 vitality scale and FACT-F total (r = 0.76) and the fatigue subscale (r = 0.77) support the convergent validity.
  
  
  CONCLUSIONS
  The Portuguese version of FACT-F is a reliable and valid instrument to assess quality of life and fatigue, representing a valid tool to screen cancer-related fatigue in Brazilian cancer patients.
authors.affiliation: Physical Therapy Department, Brazilian National Cancer Institute-INCA, Rua do Rezende 128, Centro-Rio de Janeiro, RJ 20231-092, Brazil. nelimuraki@gmail.com
authors.forename: Neli Muraki
authors.initials: NM
authors.lastname: Ishikawa
authors.forename: Luiz Claudio Santos
authors.initials: LC
authors.lastname: Thuler
authors.forename: Alessandra Grasso
authors.initials: AG
authors.lastname: Giglio
authors.forename: Clarissa Seródio da Rocha
authors.initials: CS
authors.lastname: Baldotto
authors.forename: Carlos José Coelho
authors.initials: CJ
authors.lastname: de Andrade
authors.forename: Sophie Françoise Mauricette
authors.initials: SF
authors.lastname: Derchain
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil; D005221:Fatigue / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009369:Neoplasms / Q000628:therapy*; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult