England National Registry Study

Study profile

Description

The England National Registry comprises several linked datasets based on electronic medical records. This is a cohort of all children born in English National Health Service hospitals—97% of all births in England, based on linked, national hospital (Hospital Episode Statistics, Hospital Admitted Patient Care) datasets and mortality data. Children are linked to their mothers’ and siblings’ hospital and mortality data via their birth record. Children and their mothers are followed up via hospital outpatient, emergency department, admission, and national mortality data. The cohort was further linked to national surveillance data on SARS-CoV-2 tests and results in the community and hospitals.

Two studies are currently ongoing:

  • Study 1: Short and long-term impacts of SARS-CoV-2 infection on healthcare use in children.
  • Study 2: The impact of in-utero exposure to maternal SARS-CoV-2 infections on children’s hospital admissions in England. 

Countries involved: United Kingdom 

Sample size: 13.5 million children and 97% of all births in England 

Related publications:

  • Liu M, Wijlaars L, Abdullahi F, Jackson C, Collins IJ, Thorne C, Hardelid P. Impact of in utero exposure to SARS-CoV-2 on children’s hospital admission: National birth cohort study of 262,000 children in England. medRxiv 2025.08.29.25333365. doi:10.1101/2025.08.29.25333365

Metadata collected

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 Data collected?
Demographics 
Date of birth (full or MM/YY)
Age at contact
Sex / gender
Country of birth 
Ethnic group / race / population sector
Income level 
Employment / occupation 
Other socio-economic status proxy
Education level 
Civil status (‘marital’)
Locality (of health care provision)
Locality (of residence)
Household size 
Household composition 
  
Hospitalisation 
Admission / discharge dates or duration
Episode dates
Episode type (e.g., general; birth)
Diagnosis (e.g., codes)
Procedures (e.g., codes)
Procedures dates
Dispensed medications 
ICU admission✅ *
Admission type (planned/emergency)
Hospitalisation for COVID-19
*derived 
  
Primary care, outpatient care 
Date of visit / contact✅ #
Diagnosis codes✅ #
Dispensed medications codes✅ #
Dispensed medications date✅ #
Primary care utilisation summary 
# subset 
  
Health status and exposures 
Height 
Weight 
Date of anthropometrics 
Chronic / co-morbid conditions~✅ ~~
Medications for chronic conditions 
Smoker in household 
Current smoker 
~ can include obesity ~~generated, based on hospitalisations only (primary care in subset)
  
Vaccines 
COVID-19 vaccine (timing, doses) 
Type of COVID-19 vaccine 
Other vaccinations / vaccination history 
  
COVID-19 symptoms & contacts 
COVID-19 episodes✅ **
COVID-19 symptoms (type, severity, duration) 
Influenza-like symptoms (type, timing, duration) 
COVID-19 health-seeking behaviour 
COVID-19 contacts in household 
Medications during C-19 episode 
** if hospitalised (all) or if primary care consultation (subset for England)
  
Pregnancy & birth 
Date of delivery
Length of gestation
Birthweight
Maternal age at delivery
Pregnancy complications✅ ^
Smoking pre-pregnancy 
Vaccines in pregnancy (non-COVID-19) 
Parity / nulliparity✅ ~
Pre-pregnancy body mass index 
Pregnancy outcome (e.g. miscarriage)
Mode of delivery✅ ~
Sex of baby
Congenital anomalies✅ ~
Other newborn complications
Placental weight 
Antenatal care usage 
Currently pregnant 
^if results in hospitalisation; # for included children; ~derived/estimated
  
Death 
Date of / age at death
Cause of death
  
COVID-19 laboratory tests 
Sample type tested 
Sample / specimen collection date
SARS-CoV-2 PCR test date
SARS-CoV-2 PCR pos / neg result✅ ~
SARS-CoV-2 PCR Ct Value 
SARS-CoV-2 LFT test date
SARS-CoV-2 LFT test result
Serology test date 
Serology test results 
SARS- COV-2 genomic test results 
SARS- COV-2 variant/ lineage 
Other lab tests 
~negative tests only available for a subset 
  
COVID-19 sample collection / storage 
Sample type collected 
Sample collection date 
Sample collection time 
Sample processing 
Sample quality 
Consent to use research sample 
Consent to share research sample