title: Validity of administrative data for characterizing traumatic brain injury-related hospitalizations.
abstract: OBJECTIVE
  To examine the validity of Maryland Hospital Discharge (MHD) data for identifying and characterizing traumatic brain injury (TBI)-related hospitalizations.
  
  
  METHODS
  All TBI-related hospitalizations in 1999 were identified using MHD and Maryland Trauma Registry (MTR) data. In addition, a sample of records were abstracted to compare agreement between MHD and chart data.
  
  
  RESULTS
  The MHD file identified fewer TBI cases (61%) compared to the MTR (95%). Overall, TBI-related hospitalization rates based on MHD were significantly fewer (95; 95% CI 92, 98) vs MHD and MTR (144; 95% CI 140, 147). There was good agreement between the MHD and chart data regarding skull fractures or intracranial lesions (kappa = 0.73 and 0.83, respectively), but poor agreement for neurologic abnormalities or amnesia. The MHD significantly underestimated TBI severity.
  
  
  CONCLUSIONS
  TBI cases, especially mild ones, were under-reported by MHD data. MHD data are better at detecting anatomic injuries compared to TBI symptoms and sequella.
authors.affiliation: Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA. ashore@jhsph.edu
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Shore
authors.forename: Melissa L
authors.initials: ML
authors.lastname: McCarthy
authors.forename: Tracey
authors.initials: T
authors.lastname: Serpi
authors.forename: Melanie
authors.initials: M
authors.lastname: Gertner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D010351:Patient Discharge / Q000706:statistics & numerical data*; D015203:Reproducibility of Results