title: Development and reliability testing of a standardized questionnaire to assess psoriasis phenotype.
abstract: BACKGROUND
  Psoriasis genetics researchers have utilized separate and widely differing survey instruments to capture clinical data to be utilized in genotype-phenotype studies, which make comparison and collaboration studies among these researchers difficult.
  
  
  OBJECTIVE
  The purpose of this study was to develop and validate a clinical survey instrument to facilitate future collaborative genotype-phenotype studies among psoriasis genetics researchers.
  
  
  METHODS
  The Delphi method was employed to obtain international consensus on components of the novel survey instrument. The survey was pretested for acceptability purposes, and then formally tested for reliability using 3 independent raters interviewing 48 subjects with psoriasis.
  
  
  RESULTS
  Data showed high or moderately high agreement for questions relating to place of birth (85% to 100% in agreement), family origin (kappa = 0.48 -1.0), psoriasis history (kappa = 0.66-1.0), patient medical history (kappa = 0.76-1.0), distribution of lesions (kappa = 0.73-1.0), precipitating factors (kappa = 0.79-1.0), joint involvement (kappa = 0.74-.91), and treatment history, including use of oral retinoids, methotrexate, and etanercept (kappa = 0.73-1.0). Other parameters had lower degrees of agreement.
  
  
  CONCLUSIONS
  The time involved and the need for the rater to be a clinician with knowledge of psoriasis may preclude widespread use of this survey instrument.
  
  
  CONCLUSIONS
  We developed a novel, reliable survey instrument that can be used to gather clinical information in a standardized manner from psoriasis patients participating in clinical and genetics research studies.
authors.affiliation: Department of Dermatology, George Washington University, Washington, DC 20037, USA. aehrlich@mfa.gwu.edu
authors.forename: Alison
authors.initials: A
authors.lastname: Ehrlich
authors.forename: Troy
authors.initials: T
authors.lastname: Koch
authors.forename: Bijal
authors.initials: B
authors.lastname: Amin
authors.forename: David J
authors.initials: DJ
authors.lastname: Liewehr
authors.forename: Seth M
authors.initials: SM
authors.lastname: Steinberg
authors.forename: Maria L
authors.initials: ML
authors.lastname: Turner
authors.forename: Andrew
authors.initials: A
authors.lastname: Blauvelt
mesh_terms: D006801:Humans; D010641:Phenotype; D011565:Psoriasis / Q000235:genetics*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*