CRIS Data Linkages

We have set up a Clinical Data Linkage Service (CDLS), which enables us to join or ‘link’ information (‘data’) from 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 can be linked in a way that guarantees the legal and ethical rights of patients.

Data linkage is the joining of two or more independent databases that share a variable at an individual record level – for example, someone’s GP record and their hospital record will share a unique ‘NHS number’. Linkage between different sources helps to improve the quality of information and enables researchers to look at patients’ healthcare in more detail – for example, investigating how general practice and hospital care might be better coordinated. Although datasets may be linked on unique ‘identifiers’ such as NHS number, these are all removed and the information is fully anonymised prior to any researchers being given access to it.

The CDLS has linked CRIS with a number of different databases which are described below:

Hospital Episode Statistics (HES) are held by NHS Digital (previously the Health and Social Care Information Centre- HSCIC) 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.

The CDLS holds anonymised HES data on all South London and Maudsley NHS Foundation Trust (SLaM) service users who have attended hospitals anywhere in England. In addition, the CDLS also holds anonymised HES data on the residents of the four London boroughs which form the SLaM catchment area; Southwark, Lambeth, Lewisham and Croydon. This enables researchers to compare physical illnesses and hospital use of SLaM service users to the general population; this linkage also allows researchers to investigate risk factors for physical illness within patient groups or look at how pre-existing physical health problems may impact on the outcomes of mental health treatments. The linkage between CRIS and HES is important as the information on physical health gained from HES will allow policies and interventions to be developed and evaluated so that the care for people with mental disorders can be improved.

In order to link CRIS data with HES, we send identifiable information for SLaM patients (NHS number, name, date of birth, and postcode) to NHS Digital. NHS Digital is able to use this information to link the individual records with hospital records from England. This linkage is legally permissible under the Health Research Authority’s support under Section 251 of the NHS Act 2006. This support enables temporary use of identifiers in a secure environment for accurate linkage. Once NHS Digital has linked the records, all personal information (NHS number, name, date of birth, and postcode) is destroyed and the linked records are supplied back to the CDLS. These data are fully anonymised prior to any researchers being given access to it.

Further details about HES can be found on the NHS Digital website.

If you have any questions or would like to notify us that you do not wish to have your records in CRIS and/or linked with the above datasets, please contact:

CRIS Administrator, PO 92, Institute of Psychiatry, Psychology and Neuroscience, DeCrespigny Park, London, SE5 8AF

Or email: cris.administrator@kcl.ac.uk

Or call: 020 3228 8553

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 (previously the Health and Social Care Information Centre- HSCIC). CRIS has been linked with the ONS Mortality data, and the CDLS currently holds date and cause of death information for all patients within SLAM who have died before April 2015. This linkage allows researchers to investigate the relationship between mental health and cause of death.

Previous research has found that people with mental disorders generally have a lower life expectancy than people without mental disorder, so the linkage between CRIS and ONS Mortality data is important as it helps researchers understand why this may be and provides information that will hopefully help in improving the life expectancy of individuals with mental disorders.

In order to link CRIS data with ONS Mortality data, we send identifiable information for SLaM patients (including NHS number, name, date of birth, and postcode) to NHS Digital. NHS Digital is able to use this information to link the individual records with Mortality records from England and Wales provided by the ONS. This linkage is legally permissible under the Health Research Authority’s support under Section 251 of the NHS Act 2006. This support enables temporary use of identifiers in a secure environment for accurate linkage. Once NHS Digital has linked the records, all personal information, (NHS number, name, date of birth, and postcode) is destroyed and the linked records are supplied back to the CDLS. These data are fully anonymised prior to any researchers being given access to it.

Further details about the ONS Mortality Data can be found on the NHS Digital website.

If you have any questions or would like to notify us that you do not wish to have your records in CRIS and/or linked with the above datasets, please contact:

CRIS Administrator, PO 92, Institute of Psychiatry, Psychology and Neuroscience, DeCrespigny Park, London, SE5 8AF

Or email: cris.administrator@kcl.ac.uk

Or call: 020 3228 8553

Lambeth DataNet (LDN) is a healthcare database of GP records from practices within the London borough of 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 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.

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 & Maudsley NHS Foundation Trust, who were at school and lived in Croydon, Lambeth, Lewisham or Southwark from 2008 to 2013.

This linkage will provide evidence to help families; treating clinicians and health policy makers understand the risk factors for childhood mental illnesses such as autism, attention deficit hyperactivity disorders, psychosis, obsessional compulsive disorders and depression. In addition, it will provide evidence to help clinicians and families understand the impact of childhood mental health on educational outcomes. An important objective for families who seek child and adolescent mental health care is to get their child back on track at school and improve their education performance; this linkage will enable research into how educational risks factors impact childhood mental health treatment and outcome.

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.

Reflecting this information sharing by clinical teams, CRIS as an anonymised research database is also bringing together the information contained on different KHP services. For example, the CDLS has linked BadgerNet, a healthcare database of records from neonatal units within GSTT and KCH, to CRIS. The CLDS currently hold anonymised BadgerNet data for those SLaM patients who have had a baby who has been admitted to the neonatal units in KHP. This data linkage provides a resource for investigating the outcomes of infants of mothers with a mental health condition. Neonatal health in the children of women with mental disorders is a very important issue for clinical services and the mental health of mothers is an important consideration for maternity and neonatal services. Research using this linkage will help to guide the care and advice provided to mothers during pregnancy, as well as care following childbirth.

The CDLS, in collaboration with colleagues in the CRIS team have set up a Data Linkage Service User and Carer Advisory Group. The group is a regular meeting of people with lived experience of mental illness, all of whom have an interest in mental health research involving data linkage.

The group meets on a quarterly basis and researchers are invited to present their project, where they will receive feedback and advice from members. If you would like to know more about the group, please contact Amelia Jewell (amelia.jewell@slam.nhs.uk).

Alternatively, you can check out the most recent group newsletters below:

Last updated 07/12/2016