title: An empirical method to identify patterns in the course of psychotic episodes of people with schizophrenia.
abstract: OBJECTIVE
  This paper illustrates the process of constructing, selecting and applying simple measures in order to empirically derive patterns of course of psychotic episodes in schizophrenia.
  
  
  METHODS
  Data were collected with a composite instrument constructed for a multi-centre, follow-up randomized controlled trial of adherence therapy for people with schizophrenia. The instrument included a retrospective weekly assessment of psychotic/non-psychotic status, which was used to derive the measures, and the DSM-IV course specifiers.
  
  
  RESULTS
  The measures discriminated well between different course patterns and identified homogeneous clusters of subjects which correlated with the groups derived from the DSM-IV course specifiers.
  
  
  CONCLUSIONS
  The new measures provide an empirical basis to identify specific patterns of course and to differentiate patients according to pre-defined criteria. They can be used in follow-up studies as measures of outcome, to investigate correlations between variables and to identify potential predictors of outcome.
authors.affiliation: Section of Psychiatry and Clinical Psychology, Department of Medicine and Public Health, University of Verona, Verona, Italy. lorenzo.burti@univr.it
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Burti
authors.forename: Mariangela
authors.initials: M
authors.lastname: Mazzi
authors.forename: Maarten
authors.initials: M
authors.lastname: Koeter
authors.forename: Aart
authors.initials: A
authors.lastname: Schene
authors.forename: Hedda
authors.initials: H
authors.lastname: Helm
authors.forename: Bernd
authors.initials: B
authors.lastname: Puschner
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bindman
authors.forename: Morven
authors.initials: M
authors.lastname: Leese
authors.forename: Graham
authors.initials: G
authors.lastname: Thornicroft
authors.forename: Michele
authors.initials: M
authors.lastname: Tansella
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016000:Cluster Analysis; D016208:Databases, Factual / Q000706:statistics & numerical data; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004185:Disability Evaluation; D018450:Disease Progression; D005163:Factor Analysis, Statistical; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000209:etiology*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012559:Schizophrenia / Q000150:complications*; D012565:Schizophrenic Psychology; D055815:Young Adult
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