Table 2

Setting, locations, relevant dates and other study characteristics: multisite review of ICD-10-CM codes for intracranial injury and skull fracture treated in EDs

Study sitesOne shock trauma, One ED in referral centresTwo EDs in university systemEDs in level I, II, III trauma hospitalsEDs in all acute care hospitals
State of study siteMarylandKentuckyColoradoMassachusetts
 Setting: type of hospitalLarge academic hospitals*Acute care hospitalsAcute care hospitals in 11 urban counties†All acute care hospitals in the state
Number of hospital EDs in the study222973
Percentage of state population covered by hospitals (catchment area)153883100
Dates of the ED visits in the billing datasetJanuary 2016-
December 2018
January 2016-
June 2018
January 2017-December 2017October 2015-September 2016
Number of diagnosis fields in the ED billing dataset30253034
Type of medical record reviewer18 clinical researchers2 trauma nurses1 professional MR coder3 professional MR coders
Access to electronic medical recordYesYesED report and EMS transport‡ED report and EMS transport‡
  • *In Maryland, one of the two sites was a neurotrauma referral centre, not an ED, and its trauma registry was used for sampling.

  • †The Colorado team selected the 29 acute care hospitals that had a trauma designation of level I, II or III, and located in Colorado’s 11 most populous counties. These 29 hospitals had 77% of all ED visits for intracranial injury and 81% of all ED visits for skull fractures (without an intracranial injury) in the state during the study time period.

  • ‡Additional medical documents requested in Colorado: face sheet, radiology reports, toxicology reports. Massachusetts: face sheet, radiology reports, lab work/lab notes, triage notes, history and physical.

  • ED, emergency department; EMS, emergency medical services; ICD-10-CM, International Classification of Diseases, Tenth Revision, Clinical Modification; MR, medical record.