title: Cross-Cultural Psychometric Assessment of the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) Pain Scale in the Portuguese Population.
abstract: BACKGROUND
  Chronic pain is a well-known phenomenon. The differential diagnosis between neuropathic and nociceptive pain syndromes is a challenge. Consequently, assessment instruments that can distinguish between these conditions in a standardized way are of the utmost importance. The Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) is a screening tool developed to identify chronic neuropathic pain. The aim of this study was the Portuguese language translation, linguistic adaptation of the LANSS pain scale, its semantic validation, internal consistency, temporal stability, as well its validity and discriminative power.
  
  
  METHODS
  LANSS Portuguese version scale was applied to 165 consecutive patients attending the pain clinic: 103 fulfilled the clinical criteria for the diagnosis of pain of neuropathic origin and the remaining 62 fulfilled the criteria for nociceptive pain.
  
  
  RESULTS
  The scale proved to be an internally consistent (Cronbach's alpha = 0.78) and reliable instrument with good test-retest stability (r = 0.7; P < 0.001). However, its validity and specificity with a cutoff point of ≥ 12, for differentiating patients with neuropathic pain from those with non-neuropathic pain, had 89% sensitivity, 74% specificity, positive predictive value of 85%, and negative predictive value of 81%.
  
  
  CONCLUSIONS
  The Portuguese LANSS version pain scale properties lead us to the conclusion that such a cross-cultural version is a reliable and valid instrument for the differentiation of this type of pain. Its usage is recommended.
authors.affiliation: Chronic Pain Unit, Department of Anaesthesiology, Centro Hospitalar de São João, Porto, Portugal.|Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Margarida
authors.initials: M
authors.lastname: Barbosa
authors.affiliation: Unit of Palliative Care, Leeds Institute of Health Sciences, School of Medicine, University of Leeds, Leeds, U.K.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Bennett
authors.affiliation: Department of Psychology, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Verissimo
authors.affiliation: Faculty of Medicine, University of Porto, Porto, Portugal.|Department of Endocrinology, Diabetes and Metabolism, Centro Hospitalar de São João, Porto, Portugal.
authors.forename: Davide
authors.initials: D
authors.lastname: Carvalho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059350:Chronic Pain / Q000175:diagnosis / Q000208:ethnology; D003431:Cross-Cultural Comparison; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000175:diagnosis* / Q000208:ethnology*; D010147:Pain Measurement / Q000379:methods / Q000592:standards*; D011159:Population Surveillance; D011174:Portugal / Q000453:epidemiology; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: LANSS; cross-cultural comparison; neuropathic pain; reliability; validity