title: Brazilian Portuguese version of the Revised Fibromyalgia Impact Questionnaire (FIQR-Br): cross-cultural validation, reliability, and construct and structural validation.
abstract: This study aimed to culturally adapt and validate the Revised Fibromyalgia Impact Questionnaire (FIQR) to Brazilian Portuguese, by the use of analysis of internal consistency, reliability, and construct and structural validity.
  
  
  
  A total of 100 female patients with fibromyalgia participated in the validation process of the Brazilian Portuguese version of the FIQR (FIQR-Br).The intraclass correlation coefficient (ICC) was used for statistical analysis of reliability (test-retest), Cronbach's alpha for internal consistency, Pearson's rank correlation for construct validity, and confirmatory factor analysis (CFA) for structural validity.
  
  
  
  It was verified excellent levels of reliability, with ICC greater than 0.75 for all questions and domains of the FIQR-Br. For internal consistency, alpha values greater than 0.70 for the items and domains of the questionnaire were observed. Moderate (0.40 < r < 0.70) and strong (r > 0.70) correlations were observed for the scores of domains and total score between the FIQR-Br and FIQ-Br. The structure of the three domains of the FIQR-Br was confirmed by CFA.
  
  
  
  The results of this study suggest that that the FIQR-Br is a reliable and valid instrument for assessing fibromyalgia-related impact, and supports its use in clinical settings and research. The structure of the three domains of the FIQR-Br was also confirmed. Implications for Rehabilitation Fibromyalgia is a chronic musculoskeletal disorder characterized by widespread and diffuse pain, fatigue, sleep disturbances, and depression. The disease significantly impairs patients' quality of life and can be highly disabling. To be used in multicenter research efforts, the Revised Fibromyalgia Impact Questionnaire (FIQR) must be cross-culturally validated and psychometrically tested. This paper will make available a new version of the FIQR-Br since another version already exists, but there are concerns about its measurement properties. The availability of an instrument adapted to and validated for Brazilian Portuguese may make it possible to reliably verify the effects of rehabilitation programs on disability from fibromyalgia. The FIQR-Br showed results comparable with other versions of the FIQR in other languages, thereby enabling comparison of effects of rehabilitation interventions on disability from fibromyalgia conducted in Brazil with results of studies carried out in other parts of the world.
authors.affiliation: a Ribeirão Preto Medical School , University of São Paulo (USP) , Ribeirão Preto, São Paulo , Brazil.
authors.forename: Jaqueline Basilio
authors.initials: JB
authors.lastname: Lupi
authors.affiliation: b Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto, São Paulo , Brazil.|d Post Graduate Program in Rehabilitation and Functional Performance , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto, São Paulo , Brazil.
authors.forename: Daniela Cristina
authors.initials: DC
authors.lastname: Carvalho de Abreu
authors.affiliation: a Ribeirão Preto Medical School , University of São Paulo (USP) , Ribeirão Preto, São Paulo , Brazil.|d Post Graduate Program in Rehabilitation and Functional Performance , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto, São Paulo , Brazil.
authors.forename: Mariana Candido
authors.initials: MC
authors.lastname: Ferreira
authors.affiliation: c Clinical Immunology Division of Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto, São Paulo , Brazil.
authors.forename: Renê Donizeti Ribeiro de
authors.initials: RDR
authors.lastname: Oliveira
authors.affiliation: d Post Graduate Program in Rehabilitation and Functional Performance , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto, São Paulo , Brazil.|e Department of Neurosciences and Behavioral Sciences , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto, São Paulo , Brazil.
authors.forename: Thais Cristina
authors.initials: TC
authors.lastname: Chaves
mesh_terms: D000328:Adult; D001938:Brazil; D003431:Cross-Cultural Comparison; D004185:Disability Evaluation; D005163:Factor Analysis, Statistical; D005221:Fatigue; D005260:Female; D005356:Fibromyalgia / Q000503:physiopathology* / Q000523:psychology* / Q000534:rehabilitation*; D006801:Humans; D007802:Language; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
keywords: Revised Fibromyalgia Impact Questionnaire; disability; fibromyalgia; questionnaire validation