title: Linked Records of Children with Traumatic Brain Injury. Probabilistic Linkage without Use of Protected Health Information.
abstract: OBJECTIVE
  Record linkage may create powerful datasets with which investigators can conduct comparative effectiveness studies evaluating the impact of tests or interventions on health. All linkages of health care data files to date have used protected health information (PHI) in their linkage variables. A technique to link datasets without using PHI would be advantageous both to preserve privacy and to increase the number of potential linkages.
  
  
  METHODS
  We applied probabilistic linkage to records of injured children in the National Trauma Data Bank (NTDB, N = 156,357) and the Pediatric Health Information Systems (PHIS, N = 104,049) databases from 2007 to 2010. 49 match variables without PHI were used, many of them administrative variables and indicators for procedures recorded as International Classification of Diseases, 9th revision, Clinical Modification codes. We validated the accuracy of the linkage using identified data from a single center that submits to both databases.
  
  
  RESULTS
  We accurately linked the PHIS and NTDB records for 69% of children with any injury, and 88% of those with severe traumatic brain injury eligible for a study of intervention effectiveness (positive predictive value of 98%, specificity of 99.99%). Accurate linkage was associated with longer lengths of stay, more severe injuries, and multiple injuries.
  
  
  CONCLUSIONS
  In populations with substantial illness or injury severity, accurate record linkage may be possible in the absence of PHI. This methodology may enable linkages and, in turn, comparative effectiveness studies that would be unlikely or impossible otherwise.
authors.affiliation: Tellen D. Bennett, MD, MS, Pediatric Critical Care, University of Colorado School of Medicine, Children's Hospital Colorado, Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), 13199 E Montview Blvd, Suite 300, Campus Mail F443, Aurora, CO 80045, USA, E-mail: tell.bennett@ucdenver.edu.
authors.forename: T D
authors.initials: TD
authors.lastname: Bennett
authors.forename: J M
authors.initials: JM
authors.lastname: Dean
authors.forename: H T
authors.initials: HT
authors.lastname: Keenan
authors.forename: M H
authors.initials: MH
authors.lastname: McGlincy
authors.forename: A M
authors.initials: AM
authors.lastname: Thomas
authors.forename: L J
authors.initials: LJ
authors.lastname: Cook
mesh_terms: D000293:Adolescent; D000070642:Brain Injuries, Traumatic; D002648:Child; D002675:Child, Preschool; D016494:Computer Security; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008498:Medical Record Linkage; D016347:Medical Records Systems, Computerized; D012189:Retrospective Studies; D014481:United States
keywords: Medical record linkage; brain injuries; pediatrics