NHS administrative data now linked to 1958 and 1970 birth cohort studies

News, Data release
15 February 2021

Information from the NHS about cohort members’ health care and treatment in hospitals has now been linked to two longitudinal cohort studies, which have collected survey data over six decades – the 1958 National Child Development Study (NCDS) and the 1970 British Cohort Study (BCS70).

These two new data linkages are a major enhancement to the long-running birth cohort studies. Researchers are now able to analyse the administrative health data alongside the study data to answer many more questions about the factors that influence health and the way health interacts with other facets of people’s lives.

The Hospital Episode Statistics (HES), provided by NHS Digital, include information about hospital admissions, outpatient appointments, and A&E attendance in England. These datasets, which span the period 1997-2017, provide details on diagnosis, maternity care, mental health, types of therapies and treatment length and other clinical information. With the consent of cohort members, NHS Digital have provided the HES data, which can be linked to the studies’ survey records for research purposes. These survey records document cohort members’ lives since birth and cover topics such as physical health, mental health and wellbeing, health behaviours, education, work and finances, and family.

The UCL Centre for Longitudinal Studies (CLS), which manages NCDS and BCS70, and NHS Digital adhered to strict data security protocols to protect cohort members’ identities when linking the HES data to the NCDS and BCS70 cohort members’ details. NHS data were successfully matched to the records of over 6,000 NCDS cohort members and nearly 5,500 BCS70 cohort members, who had all given their consent for the data linkage.

Cohort members’ new linked health datasets are de-identified and can be accessed by registered researchers under a secure access licence through the UK Data Service Secure Lab, which enables the data to be widely used by accredited researchers.

Additional bespoke access arrangements, which include an additional NHS data sharing agreement and data minimisation via the selection of variables, have been put in place to ensure that this secure onward sharing complies with NHS Digital requirements.

Data provided by NHS Scotland have also been linked to both NCDS and BCS70 and will be released soon through the UK Data Service.

These latest linkages are part of a wider linked data programme underway at CLS, which is home to four cohort studies. Other recent developments include linking education data and NHS Hospital Episode Statistics data to the Next Steps study, and linking education data and NHS Scotland data to the Millennium Cohort Study.

How to access the data

The linked data are available via the UK Data Service’s secure access system, the Secure Lab. Information about how users can apply for access to these data can be found on the UK Data Service website.

The datasets are included in the UK Data Service catalogue as:

National Child Development Study: Linked Health Administrative Datasets (Hospital Episode Statistics), England, 1997-2017: Secure Access (SN 8697)

1970 British Cohort Study: Linked Health Administrative Datasets (Hospital Episode Statistics), England, 1997-2017: Secure Access (SN 8733)

Find out more
More information on the linked data datasets is available in the two CLS user guides, available from the CLS website and the UK Data Service website:

National Child Development Study, Linked health administrative datasets – Hospital Episode Statistics – user guide.

1970 British Cohort Study, Linked health administrative datasets – Hospital Episode Statistics – user guide.


  1. CLS securely transferred personal details (such as the cohort member’s name, sex, date of birth and address) when working with NHS Digital to link the health data to the studies. No other information about the person was sent, or any of their answers to the surveys. NHS Digital only used these details to identify the person in their systems and to send CLS their health records. All linked data are made available to researchers under a secure access licence. Names, addresses, National Insurance and/or NHS numbers, are never disclosed.
  2. Highly confidential datasets managed by the UK Data Service are classified as controlled data, which are not available under standard UK Data Service access arrangements. Users applying for controlled data have additional conditions of access, including the completion of special forms and attending a training course. Once approval is granted, datasets are available to view on the UK Data Service’s secure system, the Secure Lab. Data accessed in this way cannot be downloaded. Once researchers and their projects are approved, they can analyse the data remotely from their organisational desktop in the UK. For more details on the UK Data Service’s response to the transition to remote working, please visit ukdataservice.ac.uk/covid-19.

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