Watch this animation to find out more about data linkage and how it has contributed to the evolution of healthcare research. The animation was created by a multidisciplinary team at the NIHR Maudsley Biomedical Research Centre (BRC).

You can find a list of local and national data linkage services below. 

Clinical Data Linkage Service (CDLS)

Informatics researchers have set up a Clinical Data Linkage Service (CDLS), which enables us to join or ‘link’ information from the Clinical Record Interactive Search (CRIS) with other clinical sources within a secure ‘safe haven’. Safe Havens have been set up in the NHS to ensure that confidential patient information is shared safely and anonymously. 

The CDLS has linked CRIS with a number of different databases briefly described below. For more detailed information visit the NIHR Maudsley Biomedical Research Centre's website.  

CRIS - Hospital Episode Statistics (HES)

Hospital Episode Statistics (HES) are held by NHS Digital and include all accident and emergency, hospital admissions and outpatient visits which occur in all hospitals throughout England. The CDLS has linked CRIS to HES and currently this linkage includes important clinical information such as diagnoses, operations or the speciality of the treating clinician; demographic information such as age, gender and ethnicity; and also administrative data such as methods of admission and discharge.

CRIS - Office for National Statistics (ONS) Mortality

The Office for National Statistics (ONS) collects information on cause of death from an individual’s death certificate; this information is held by NHS Digital . CRIS has been linked with the ONS Mortality data, and the CDLS currently holds date and cause of death information for all patients within South London and Maudsley NHS Foundation Trust who have died before January 2018. This linkage allows researchers to investigate the relationship between mental health and cause of death.

CRIS - Lambeth DataNet (LDN)

Lambeth DataNet (LDN) is a healthcare database of GP records from practices within Lambeth. The CDLS has linked LDN to CRIS and currently hold anonymised LDN data for patients of the South London and Maudsley NHS Foundation Trust (SLaM) who are registered with a GP in Lambeth. The CDLS also holds anonymised LDN data for residents of Lambeth who are not SLAM patients and this allows researchers to compare how mental disorders affect general health care, comparing people with and without a mental disorder. This data linkage provides a resource for investigating the physical health and health care of people with mental disorders with the aim of improving the care that they receive.

CRIS - National Pupil Database (NPD)

This data linkage provides a resource for investigating the relationship between mental health and educational outcome. The CDLS holds anonymised data from the Department for Education National Pupil Database linked with Child and Adolescent Mental Health Service (CAMHS) CRIS records, as well as an anonymised control sample of all school aged children, who are not patients of the South London and Maudsley NHS Foundation Trust, who were at school and lived in Croydon, Lambeth, Lewisham or Southwark from 2008 to 2013.

King’s Health Partners (KHP)

King’s Health Partners (KHP) is an Academic Health Science Centre – a government initiative to bring universities and NHS Trusts together in closer working partnerships. KHP brings together King’s College London with South London and Maudsley NHS Foundation Trust (SLaM), Guy's and St Thomas' NHS Foundation Trust (GSTT), and King’s College Hospital NHS Foundation Trust(KCH). Information sharing is core to KHP – meaning that a doctor treating someone at GSTT is able to see that person’s SLaM or KCH record, or a nurse at SLAM is able to access records at GSTT or KCH.

eLIXIR - Early Lifecourse data Cross-LInkage in Research 

The aim of the eLIXIR project is to provide information about health in pregnancy and across the life span in a large number of people to help us work out when and how health problems begin, how we might prevent them and what treatments work in some people and not others. In England, mother, baby and child health records are kept in many different places and are not routinely linked to each other. eLIXIR will pull these data together and anonymise them for use in research.

CRIS - UK Census Data

The Office for National Statistics (ONS) census is a national survey which takes place every 10 years in England and Wales on a nominated day. Every effort is made to include all people resident in England and Wales on that day and ask them questions about their housing, social, health, and living circumstances. Individuals are also asked about their ethnicity, country of birth, and citizenship. Previous census surveys were conducted in 2001 and 2011. The CDLS has linked CRIS to 2011 census data; this linkage is the first between NHS mental health records and census data in England.

This data linkage provides a resource for investigating the impact of social and demographic factors, such as employment, migration status, and poverty, on mental health treatment and outcomes. This includes examining health inequalities in ethnic minority service users, as well as the social and economic predictors of illness course and mortality.

CRIS - National Cancer Registration and Analysis Service (NCRAS)

The NCRAS, run by Public Health England (PHE), collects information about every patient diagnosed with a malignant tumour in England in order to support public health, service monitoring, and research. The NCRAS collects information on over 300,000 cases of cancer every year, including detailed data about the type of cancer, how advanced it is, and the treatment the patient receives. In collaboration with PHE, the CDLS have linked CRIS to cancer data from the NCRAS along with information on hospital visits from HES, and mortality data.

CRIS - Child and Family Court Advisory and Support Service (CAFCASS)

The Child and Family Court Advisory and Support Service (CAFCASS) represent children in family court cases in England. It is CAFCASS’s duty to safeguard and promote the welfare of children going through the family justice system. CAFCASS collect data on family court cases that they are involved in. CRIS has been linked with CAFCASS data to enable researchers to understand the mental health needs of mothers involved in care proceedings (family court cases where the council applies to have a child removed from parental care due to serious concern over their health or wellbeing).

CRIS - Maudsley BioResource

The NIHR Maudsley BioResource for Mental Health focuses on research into psychiatry and neurology. It stores samples from volunteers with diagnoses such as dementia, schizophrenia, autism, mood and eating disorders, and others, to help advance research into those areas and support the development of more efficient treatments. The BioResource currently has samples stored for over 10,000 volunteers.

eLIXIR: reducing the risk of health problems for mothers and children 

eLIXIR (early-LIfe data cross-LInkage in Research) aims to combine information from health records and blood samples from mothers and children from a large population in south London. This resource will help researchers explore the ‘life course’ common diseases, and help scientists and doctors understand more about disease and the processes leading up to disease – ultimately, the aim is to reduce the risk of health problems for mothers and children. 

The eLIXIR partnership includes members from King’s College London’s Faculty of Life Sciences and Medicine and the Institute of Psychiatry, Psychology & Neurosciences, and is led by Professor Lucilla Poston.

More information on eLIXIR

NIHR Health Informatics Collaborative

The NIHR Health Informatics Collaborative (HIC) is a collaboration between 25 NHS trusts aimed to support the establishment and maintenance of catalogued, comparable, comprehensive flows of patient data at each trust, and to create a governance framework for data sharing and re-use across the trusts and partner organisations.

More information on NIHR HIC