title: Cross-cultural adaptation and validation of a Brazilian Portuguese version of the chronic pain grade.
abstract: OBJECTIVE
  To verify the reliability and validity of a Brazilian Portuguese version of the chronic pain grade (CPG-Br).
  
  
  METHODS
  Cultural adaptation was made in accordance with established guidelines, with modifications aiming at improving this process. Adaptations were made based on interviews with 45 chronic pain patients from São Paulo city. Validation was studied by concurrent application of the short-form-36 health survey (SF-36) and other questionnaires to 283 participants with chronic pain from the general population. Temporal stability was verified by a second application to 131 individuals.
  
  
  RESULTS
  Factor analysis resulted in a two-factor solution with factors named characteristic pain intensity and activity limitation due to pain. Alpha coefficients of 0.78 and 0.70 and intraclass correlation coefficients of 0.76 and 0.72 for each factor indicated good internal consistency and temporal stability. Significant correlations between CPG-Br and SF-36, Roland-Morris disability questionnaire and neck disability index scores were noted. A consistent linear trend was also observed between pain grades and SF-36 scores. Frequency of use of pain medications and of pain-related medical visits increased with pain grade.
  
  
  CONCLUSIONS
  This Brazilian Portuguese version of the chronic pain grade, tested on a sample of the Brazilian population, demonstrated good reliability and validity.
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil. ebracher@terra.com.br
authors.forename: Eduardo S B
authors.initials: ES
authors.lastname: Bracher
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pietrobon
authors.forename: José
authors.initials: J
authors.lastname: Eluf-Neto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil; D003431:Cross-Cultural Comparison; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007802:Language; D017116:Low Back Pain / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods*; D011594:Psychometrics / Q000295:instrumentation*; D015203:Reproducibility of Results; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires / Q000592:standards; D055815:Young Adult