title: Evaluation of data obtained from military disability medical administrative databases for service members with schizophrenia or bipolar disorder.
abstract: OBJECTIVE
  We are studying associations between selected biomarkers and schizophrenia or bipolar disorder among military personnel. To assess potential diagnostic misclassification and to estimate the date of illness onset, we reviewed medical records for a subset of cases.
  
  
  METHODS
  Two psychiatrists independently reviewed 182 service medical records retrieved from the Department of Veterans Affairs. Data were evaluated for diagnostic concordance between database diagnoses and reviewers. Interreviewer variability was measured by using proportion of agreement and the kappa statistic. Data were abstracted to estimate date of onset.
  
  
  RESULTS
  High levels of agreement existed between database diagnoses and reviewers (proportion, 94.7%; kappa = 0.88) and between reviewers (proportion, 92.3%; kappa = 0.87). The median time between illness onset and initiation of medical discharge was 1.6 and 1.1 years for schizophrenia and bipolar disorder, respectively.
  
  
  CONCLUSIONS
  High levels of agreement between investigators and database diagnoses indicate that diagnostic misclassification is unlikely. Discharge procedure initiation date provides a suitable surrogate for disease onset.
authors.affiliation: Department of Epidemiology, Division of Preventive Medicine, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Millikan
authors.forename: Natalya S
authors.initials: NS
authors.lastname: Weber
authors.forename: David W
authors.initials: DW
authors.lastname: Niebuhr
authors.forename: E Fuller
authors.initials: EF
authors.lastname: Torrey
authors.forename: David N
authors.initials: DN
authors.lastname: Cowan
authors.forename: Yuanzhang
authors.initials: Y
authors.lastname: Li
authors.forename: Brenda
authors.initials: B
authors.lastname: Kaminski
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000453:epidemiology / Q000523:psychology*; D016208:Databases, Factual; D006233:Persons with Disabilities / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008887:Military Medicine; D008889:Military Personnel; D011581:Psychological Tests; D011594:Psychometrics; D012189:Retrospective Studies; D012559:Schizophrenia / Q000453:epidemiology*; D012565:Schizophrenic Psychology; D014481:United States; D014493:United States Department of Veterans Affairs