title: Outcomes From Health Information Exchange: Systematic Review and Future Research Needs.
abstract: BACKGROUND
  Health information exchange (HIE), the electronic sharing of clinical information across the boundaries of health care organizations, has been promoted to improve the efficiency, cost-effectiveness, quality, and safety of health care delivery.
  
  
  OBJECTIVE
  To systematically review the available research on HIE outcomes and analyze future research needs.
  
  
  METHODS
  Data sources included citations from selected databases from January 1990 to February 2015. We included English-language studies of HIE in clinical or public health settings in any country. Data were extracted using dual review with adjudication of disagreements.
  
  
  RESULTS
  We identified 34 studies on outcomes of HIE. No studies reported on clinical outcomes (eg, mortality and morbidity) or identified harms. Low-quality evidence generally finds that HIE reduces duplicative laboratory and radiology testing, emergency department costs, hospital admissions (less so for readmissions), and improves public health reporting, ambulatory quality of care, and disability claims processing. Most clinicians attributed positive changes in care coordination, communication, and knowledge about patients to HIE.
  
  
  CONCLUSIONS
  Although the evidence supports benefits of HIE in reducing the use of specific resources and improving the quality of care, the full impact of HIE on clinical outcomes and potential harms are inadequately studied. Future studies must address comprehensive questions, use more rigorous designs, and employ a standard for describing types of HIE.
  
  
  BACKGROUND
  PROSPERO Registry No CRD42014013285; http://www.crd.york.ac.uk/PROSPERO/ display_record.asp?ID=CRD42014013285 (Archived by WebCite at http://www.webcitation.org/6dZhqDM8t).
authors.affiliation: Pacific Northwest Evidence-Based Practice Center, Department of Medical Informatics & Clinical Epidemiology, Oregon Health & Science University, Portland, OR, United States. hersh@ohsu.edu.
authors.forename: William R
authors.identifier: http://orcid.org/0000-0002-4114-5148
authors.initials: WR
authors.lastname: Hersh
authors.forename: Annette M
authors.identifier: http://orcid.org/0000-0002-9100-8678
authors.initials: AM
authors.lastname: Totten
authors.forename: Karen B
authors.identifier: http://orcid.org/0000-0001-8709-6292
authors.initials: KB
authors.lastname: Eden
authors.forename: Beth
authors.identifier: http://orcid.org/0000-0001-9945-6099
authors.initials: B
authors.lastname: Devine
authors.forename: Paul
authors.identifier: http://orcid.org/0000-0001-9818-954X
authors.initials: P
authors.lastname: Gorman
authors.forename: Steven Z
authors.identifier: http://orcid.org/0000-0002-6198-7617
authors.initials: SZ
authors.lastname: Kassakian
authors.forename: Susan S
authors.identifier: http://orcid.org/0000-0003-4257-6879
authors.initials: SS
authors.lastname: Woods
authors.forename: Monica
authors.identifier: http://orcid.org/0000-0002-0194-1596
authors.initials: M
authors.lastname: Daeges
authors.forename: Miranda
authors.identifier: http://orcid.org/0000-0003-2486-2775
authors.initials: M
authors.lastname: Pappas
authors.forename: Marian S
authors.identifier: http://orcid.org/0000-0002-6911-268X
authors.initials: MS
authors.lastname: McDonagh
keywords: diagnostic tests; health information exchange; outcome assessment (health care); patient readmission; routine; systematic review