Linked electronic health records for research on a nationwide cohort of more than 54 million people in England: data resource

BMJ. 2021 Apr 7:373:n826. doi: 10.1136/bmj.n826.

Abstract

Objective: To describe a novel England-wide electronic health record (EHR) resource enabling whole population research on covid-19 and cardiovascular disease while ensuring data security and privacy and maintaining public trust.

Design: Data resource comprising linked person level records from national healthcare settings for the English population, accessible within NHS Digital's new trusted research environment.

Setting: EHRs from primary care, hospital episodes, death registry, covid-19 laboratory test results, and community dispensing data, with further enrichment planned from specialist intensive care, cardiovascular, and covid-19 vaccination data.

Participants: 54.4 million people alive on 1 January 2020 and registered with an NHS general practitioner in England.

Main measures of interest: Confirmed and suspected covid-19 diagnoses, exemplar cardiovascular conditions (incident stroke or transient ischaemic attack and incident myocardial infarction) and all cause mortality between 1 January and 31 October 2020.

Results: The linked cohort includes more than 96% of the English population. By combining person level data across national healthcare settings, data on age, sex, and ethnicity are complete for around 95% of the population. Among 53.3 million people with no previous diagnosis of stroke or transient ischaemic attack, 98 721 had a first ever incident stroke or transient ischaemic attack between 1 January and 31 October 2020, of which 30% were recorded only in primary care and 4% only in death registry records. Among 53.2 million people with no previous diagnosis of myocardial infarction, 62 966 had an incident myocardial infarction during follow-up, of which 8% were recorded only in primary care and 12% only in death registry records. A total of 959 470 people had a confirmed or suspected covid-19 diagnosis (714 162 in primary care data, 126 349 in hospital admission records, 776 503 in covid-19 laboratory test data, and 50 504 in death registry records). Although 58% of these were recorded in both primary care and covid-19 laboratory test data, 15% and 18%, respectively, were recorded in only one.

Conclusions: This population-wide resource shows the importance of linking person level data across health settings to maximise completeness of key characteristics and to ascertain cardiovascular events and covid-19 diagnoses. Although this resource was initially established to support research on covid-19 and cardiovascular disease to benefit clinical care and public health and to inform healthcare policy, it can broaden further to enable a wide range of research.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • COVID-19 / diagnosis
  • COVID-19 / epidemiology*
  • COVID-19 Testing
  • COVID-19 Vaccines
  • Cardiovascular Diseases / diagnosis
  • Cardiovascular Diseases / epidemiology*
  • Child
  • Child, Preschool
  • Cohort Studies
  • Electronic Health Records*
  • England / epidemiology
  • Female
  • Hospitalization / statistics & numerical data
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Medical Record Linkage*
  • Middle Aged
  • Primary Health Care / statistics & numerical data
  • Young Adult

Substances

  • COVID-19 Vaccines