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Improving data sharing between acute hospitals in England: an overview of health record system distribution and retrospective observational analysis of inter-hospital transitions of care
  1. Leigh R Warren1,
  2. Jonathan Clarke1,2,3,4,
  3. Sonal Arora1,
  4. Ara Darzi1
  1. 1 Department of Surgery and Cancer, Imperial College London, London, UK
  2. 2 Centre for Health Policy, Imperial College London, London, UK
  3. 3 Centre for Mathematics of Precision Healthcare, Imperial College London, London, UK
  4. 4 Department of Biostatistics, Harvard University, Boston, United States
  1. Correspondence to Dr Leigh R Warren; leigh.warren{at}


Objectives To determine the frequency of use and spatial distribution of health record systems in the English National Health Service (NHS). To quantify transitions of care between acute hospital trusts and health record systems to guide improvements to data sharing and interoperability.

Design Retrospective observational study using Hospital Episode Statistics.

Setting Acute hospital trusts in the NHS in England.

Participants All adult patients resident in England that had one or more inpatient, outpatient or accident and emergency encounters at acute NHS hospital trusts between April 2017 and April 2018.

Primary and secondary outcome measures Frequency of use and spatial distribution of health record systems. Frequency and spatial distribution of transitions of care between hospital trusts and health record systems.

Results 21 286 873 patients were involved in 121 351 837 encounters at 152 included trusts. 117 (77.0%) hospital trusts were using electronic health records (EHR). There was limited regional alignment of EHR systems. On 11 017 767 (9.1%) occasions, patients attended a hospital using a different health record system to their previous hospital attendance. 15 736 863 (73.9%) patients had two or more encounters with the included trusts and 3 931 255 (25.0%) of those attended two or more trusts. Over half (53.6%) of these patients had encounters shared between just 20 pairs of hospitals. Only two of these pairs of trusts used the same EHR system.

Conclusions Each year, millions of patients in England attend two or more different hospital trusts. Most of the pairs of trusts that commonly share patients do not use the same record systems. This research highlights significant barriers to inter-hospital data sharing and interoperability. Findings from this study can be used to improve electronic health record system coordination and develop targeted approaches to improve interoperability. The methods used in this study could be used in other healthcare systems that face the same interoperability challenges.

  • health policy
  • health informatics
  • health & safety
  • organisation of health services
  • quality in health care
  • health economics

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  • Contributors LW and JC were involved in all aspects of the study. SA and AD were involved in planning, interpretation, writing, reviewing and supervising the study. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.

  • Funding This article refers to independent research supported by grants from the National Institute for Health Research (NIHR) Imperial Patient Safety and Translational Research Centre (PSTRC) and The Peter Sowerby Foundation. Infrastructure support was provided by the NIHR Imperial Biomedical Research Centre (BRC). The views expressed in this publication are those of the authors and not necessarily those of the NHS, NIHR or the Department of Health. Funders had no role in the writing of the manuscript or decision to submit for publication. Researchers were independent from funders and all authors had full access to all the data in the study and take responsibility for the integrity of the data and accuracy of the data analysis.

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  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval This research received local ethical approval through the Imperial College Research Ethics Committee (17IC4178). The use of Hospital Episode Statistics data for this project was approved by NHS Digital. Patient-level data was anonymised and patient-level consent was not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request. Data may be obtained from a third party and are not publicly available.