title: Inter-observer reliability of the PASI in a clinical setting.
abstract: BACKGROUND
  With the evolving emphasis on evidence-based practice, the use of reliable clinical scales forms an important foundation for clinical assessment. The psoriasis area and severity index (PASI) is the most widely used tool for the measurement of psoriasis severity; however, there has been some debate over the potential reproducibility of PASI scoring.
  
  
  OBJECTIVE
  To determine the inter-observer reliability of the PASI at a large tertiary hospital with a psoriasis treatment centre.
  
  
  METHODS
  In total, 34 patients who were due for their 3-monthly follow up at a psoriasis treatment centre were independently evaluated by five clinical staff (observers) from the Department of Dermatology. Each observer independently determined the PASI score of each patient and the inter-observer reliability coefficient was determined by employing intra-class correlation coefficients (ICC).
  
  
  RESULTS
  There was a significant degree of concordance among the PASI scoring of observers (ICC = 0.804; CI 95%: 0.706-0.883).
  
  
  CONCLUSIONS
  Our cross-sectional study suggests that the PASI provides a reproducible method of assessing psoriasis severity among patients seen in a busy dermatology clinic at a large tertiary hospital.
authors.affiliation: Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Samantha
authors.initials: S
authors.lastname: Cabrera
authors.forename: Niranthari
authors.initials: N
authors.lastname: Chinniah
authors.forename: Nannette
authors.initials: N
authors.lastname: Lock
authors.forename: Geoffrey D
authors.initials: GD
authors.lastname: Cains
authors.forename: Jane
authors.initials: J
authors.lastname: Woods
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003880:Dermatology / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011565:Psoriasis / Q000473:pathology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D055815:Young Adult
keywords: ICC; PASI; PASI reliability; inter-observer reliability; interrater reliability; psoriasis; psoriasis area and severity index; psoriasis assessment; psoriasis severity; reliability