title: The Discriminatory Ability of the Fibromyalgia Rapid Screening Tool (FiRST): An International Study in Spain and Four Latin American Countries.
abstract: To assess the transcultural equivalency of the Spanish version of the Fibromyalgia Rapid Screening Tool (FiRST) and its discriminatory ability in different Latin American samples.
  
  
  
  Validation study.
  
  
  
  Departments of Rheumatology in general hospitals and private centers; fibromyalgia unit in a university hospital.
  
  
  
  350 chronic pain patients from Spain, Argentina, Mexico, Peru, and Ecuador.
  
  
  
  The cultural relevance of the Spanish version of the FiRST was evaluated. The ability of the FiRST as a screening tool for fibromyalgia was assessed by logistic regression analysis. To determine the degree to which potential confounders, such as differences in demographics, pain, affective distress, catastrophizing, and disability, might affect the discriminatory ability, the tool was reassessed by hierarchical multivariate logistic regression.
  
  
  
  Slightly different versions of the FiRST were recommended for use in each Latin American subsample. The FiRST showed acceptable criterion validity and was able to discriminate between fibromyalgia and non-fibromyalgia patients even after controlling for the effect of potential confounders. However, low specificities were observed in samples from Spain and Mexico.
  
  
  
  The Spanish version of the FiRST may be used as a screening tool for fibromyalgia in several Latin American subsamples, even in those patients with high scores on potential confounders. In Spain and Mexico, the low specificity of the FiRST suggests, however, that it would be best used to support a suspected diagnosis of fibromyalgia, rather than to exclude the diagnosis.
authors.affiliation: *Fibromyalgia Unit, Rheumatology Service, Institut Clínic de l'Aparell Locomotor, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Collado
authors.affiliation: Fibromyalgia Unit, Psychiatry and Clinical Psychology Service, Institut Clínic de Neurociències, Hospital Clínic de Barcelona, Barcelona, Spain xtorres@clinic.ub.es.
authors.forename: Xavier
authors.initials: X
authors.lastname: Torres
authors.affiliation: Rheumatology Service, IRO, Buenos Aires, Argentina.
authors.forename: Osvaldo D
authors.initials: OD
authors.lastname: Messina
authors.affiliation: Rheumatology Service, Centro Diagnóstico de la Osteoporosis y Enfermedades Reumáticas (CEDOR), Lima, Peru.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Vidal
authors.affiliation: Clinical Epidemiology Unit, Hospital Infantil Federico Gómez, Mexico D.F., Mexico Faculty of Medicine, Universidad Nacional Autonoma De Mexico, Mexico D.F. Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: Clark
authors.affiliation: Rheumatology Service, Centro De Reumatología y Rehabilitación, Guayaquil, Ecuador.
authors.forename: Carlos
authors.initials: C
authors.lastname: Ríos
authors.affiliation: *Fibromyalgia Unit, Rheumatology Service, Institut Clínic de l'Aparell Locomotor, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Emília
authors.initials: E
authors.lastname: Solé
authors.affiliation: *Fibromyalgia Unit, Rheumatology Service, Institut Clínic de l'Aparell Locomotor, Hospital Clínic de Barcelona, Barcelona, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Arias
authors.affiliation: **Centre De La Douleur, Hôpital Cochin, INSERM Unit 987, Université Paris Descartes, Paris, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Perrot
authors.affiliation: Pfizer, Inc. Pain Division for Latin America, Mexico D.F., Mexico.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Salomon
mesh_terms: D000328:Adult; D000368:Aged; D001118:Argentina / Q000208:ethnology; D003431:Cross-Cultural Comparison; D004484:Ecuador / Q000208:ethnology; D005356:Fibromyalgia / Q000175:diagnosis* / Q000208:ethnology*; D006801:Humans; D038622:Internationality; D008800:Mexico / Q000208:ethnology; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods / Q000592:standards*; D010568:Peru / Q000208:ethnology; D015203:Reproducibility of Results; D013030:Spain / Q000208:ethnology; D011795:Surveys and Questionnaires / Q000592:standards*
keywords: Diagnosis; Differential; Fibromyalgia; Psychometrics; Questionnaires