title: Psychometric characteristics of the Brazilian-Portuguese versions of the Functional Rating Index and the Roland Morris Disability Questionnaire.
abstract: METHODS
  Translation, cross-cultural adaptation and psychometric testing of self-report outcome measurements.
  
  
  OBJECTIVE
  The aims of this study were to adapt the Functional Rating Index (FRI) to Brazilian-Portuguese and to test the psychometric properties of this new questionnaire and the Brazilian-Roland Morris Disability Questionnaire (RMDQ).
  
  
  BACKGROUND
  Self-report measures are commonly used in clinical practice and in research studies. Most existing questionnaires were developed in English and there is only 1 Brazilian-Portuguese cross-cultural adaptation of a spine outcome measure.
  
  
  METHODS
  The FRI was translated and adapted into Brazilian-Portuguese according to the Guidelines for the process of cross-cultural adaptation of self report measures. The Brazilian-Portuguese FRI and RMDQ were tested for internal consistency, reliability, ceiling and floor effects, construct validity, and responsiveness in 140 low back pain (LBP) patients.
  
  
  RESULTS
  A very high level of internal consistency (Cronbach's alpha = 0.92) and reliability [ICC = 0.95 (95% confidence interval, 0.93-0.97)] was shown for both instruments. The FRI and RMDQ were highly correlated (r = 0.80), while both the FRI and RMDQ were moderately correlated with pain at baseline (r = 0.67 and 0.55, respectively). No ceiling or floor effects were detected; however, the responsiveness of both questionnaires was quite small (RMDQ ES = 0.10 [84% confidence interval, 0.04-0.16] and FRI ES = 0.18 [84% confidence interval, 0.11-0.24]).
  
  
  CONCLUSIONS
  The results of this study indicate that the Brazilian-Portuguese versions of the FRI and RMDQ are reliable and valid instruments for the measurement of disability in Brazilian-Portuguese-speaking patients with LBP presenting for physiotherapy treatment. Both instruments are suitable for use in clinical practice and research studies.
authors.affiliation: Back Pain Research Group, School of Physiotherapy, University of Sydney, Lidcombe NSW, Australia. lcos3060@usyd.edu.au
authors.forename: Leonardo Oliveira Pena
authors.initials: LO
authors.lastname: Costa
authors.forename: Chris G
authors.initials: CG
authors.lastname: Maher
authors.forename: Jane
authors.initials: J
authors.lastname: Latimer
authors.forename: Paulo Henrique
authors.initials: PH
authors.lastname: Ferreira
authors.forename: Giovanni Campos
authors.initials: GC
authors.lastname: Pozzi
authors.forename: Rodrigo Nogueira
authors.initials: RN
authors.lastname: Ribeiro
mesh_terms: D000328:Adult; D001938:Brazil; D032882:Comprehension; D003431:Cross-Cultural Comparison; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007802:Language; D017116:Low Back Pain / Q000175:diagnosis* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D026741:Physical Therapy Modalities; D011174:Portugal; D011594:Psychometrics; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires