title: Generalisability of results from randomised drug trials. A trial on antimanic treatment.
abstract: BACKGROUND
  Exemplified by a randomised trial on antimanic treatment, this paper addresses the question of whether selection of patients for drug trials may limit the applicability of study results from the randomised patients to a wider population.
  
  
  METHODS
  During two-year period, all consecutively admitted patients from a defined catchment area were screened for inclusion criteria concerning age, diagnosis and severity of illness. The subsequently excluded subgroups of patients were compared with the randomised patients by multivariate data analysis.
  
  
  RESULTS
  One hundred and sixty-four patients met the inclusion criteria. However, after exclusion for various reasons, only 27 (17%) patients remained for randomisation. The randomised patients and the excluded patients differed substantially.
  
  
  CONCLUSIONS
  The generalisability of trial results is limited. Reports of randomised drug trials should carefully describe the screening procedure for inclusion and, when possible, present relevant comparisons-between the randomised patients and the various subgroups of excluded patients.
authors.affiliation: Institute for Basic Psychiatric Research, Department of Psychiatric Demography, Psychiatric Hospital in Aarhus, Denmark.
authors.forename: R W
authors.initials: RW
authors.lastname: Licht
authors.forename: G
authors.initials: G
authors.lastname: Gouliaev
authors.forename: P
authors.initials: P
authors.lastname: Vestergaard
authors.forename: M
authors.initials: M
authors.lastname: Frydenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018692:Antimanic Agents / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000188:drug therapy*; D002998:Clonazepam / Q000627:therapeutic use; D003006:Clopenthixol / Q000627:therapeutic use*; D003625:Data Collection; D004338:Drug Combinations; D006801:Humans; D018020:Lithium Compounds / Q000627:therapeutic use*; D008875:Middle Aged; D018579:Patient Selection; D015983:Selection Bias; D016896:Treatment Outcome
chemical_list: D018692:Antimanic Agents; D004338:Drug Combinations; D018020:Lithium Compounds; D002998:Clonazepam; D003006:Clopenthixol