title: Where should electronic records for patients be stored?
abstract: BACKGROUND
  The importance of a nationwide health information infrastructure (NHII) is widely recognized. Patient data may be stored where it happens to be created (the distributed or institution-centric model) or in one place for a given patient (the centralized or patient-centric model). Minimal data is available regarding the performance implications of these alternative architectural choices.
  
  
  OBJECTIVE
  To help identify the architecture best suited for efficient and complete nationwide health information exchange based on the large-scale operational characteristics of these architectures.
  
  
  METHODS
  We used simulation to study the impact of health care record (data) fragmentation and probability of encounter on transaction volume and data retrieval failure rate as markers of performance for each of the above architectures.
  
  
  RESULTS
  Data fragmentation and the probability of encounter directly correlate with transaction volume and are significantly higher for the distributed model when the number of data nodes >4 (p<0.0001). The number of data retrieval failures increases in proportion to fragmentation and is significantly higher for the distributed model when the number of data nodes ≥2 (p<0.0059).
  
  
  CONCLUSIONS
  In simulation studies, the distributed model scaled poorly in terms of data availability and integrity with a higher failure rate when compared to the centralized model of data storage. Choice of architecture may have implications on the efficiency, usability, and effectiveness of the NHII at the point of care.
authors.affiliation: Department of Medicine, Mount Sinai School of Medicine, New York, United States. vijay.lapsia@mssm.edu
authors.forename: Vijay
authors.initials: V
authors.lastname: Lapsia
authors.forename: Kenneth
authors.initials: K
authors.lastname: Lamb
authors.forename: William A
authors.initials: WA
authors.lastname: Yasnoff
mesh_terms: D003195:Computer Communication Networks; D003198:Computer Simulation; D006801:Humans; D016247:Information Storage and Retrieval; D008498:Medical Record Linkage / Q000379:methods*; D016347:Medical Records Systems, Computerized; D008962:Models, Theoretical