title: Examination of anomalous self-experience in first-episode psychosis: interrater reliability.
abstract: BACKGROUND
  The growing research focus on early detection of schizophrenia has fostered an increasing interest in the nonpsychotic experiential anomalies that may antedate schizophrenia spectrum disorders and assist early differential diagnosis. The Examination of Anomalous Self-Experience (EASE) is a phenomenologically inspired checklist, specifically designed to support the comprehensive assessment of these characteristic subjective experiences.
  
  
  OBJECTIVE
  To assess the interrater reliability of the EASE.
  
  
  METHODS
  Twenty-five first-episode psychosis (FEP) patients were interviewed with the EASE. Videotaped interviews were blindly reevaluated. Internal consistency, overall interrater correlation and item interrater agreement (Cohen's kappa) were estimated.
  
  
  RESULTS
  The EASE showed good to excellent internal consistency across the two raters (Cronbach's alpha above 0.87) and an overall inter-rater correlation above 0.80 (Spearman's rho, p < 0.001). The average kappa of the EASE was 0.65, ranging from 0.51 to 0.73 over the 5 domains; kappa values at an item level were very good in 9 items, good in 20 items, moderate in 11 items and fair in 4 items.
  
  
  CONCLUSIONS
  The EASE provides a reliable and internally consistent clinical tool for the assessment of subjective experience in FEP patients, suggesting that this instrument could usefully supplement standard clinical assessments during the onset phase of psychosis.
authors.affiliation: Department of Mental Health Research and Development, Division of Mental Health and Addiction, Vestre Viken Hospital Trust, Lier, Norway. paul.moller @ vestreviken.no
authors.forename: Paul
authors.initials: P
authors.lastname: Møller
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Haug
authors.forename: Andrea
authors.initials: A
authors.lastname: Raballo
authors.forename: Josef
authors.initials: J
authors.lastname: Parnas
authors.forename: Ingrid
authors.initials: I
authors.lastname: Melle
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D011618:Psychotic Disorders / Q000175:diagnosis / Q000523:psychology*; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis; D012565:Schizophrenic Psychology; D011795:Surveys and Questionnaires