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Frequently asked questions about the use of service user data in the EXTEND study

This page is intended to provide additional details about the use of personal data in the EXTEND Study, and may be updated with further information in future.


About the study

What is Early Intervention in Psychosis?

An Early Intervention in Psychosis (EIP) service offers treatment in the community to people with a first episode of psychosis. Psychosis is a severe and distressing form of mental illness that causes hallucinations and delusions.  EIP offers care that includes medication, talking therapies, education about psychosis, physical health advice, support for families, and regular contact. There are over 150 EIP teams in England who treat over 10,000 new people per year. Research has shown that EIP is effective, that people prefer it to other forms of treatment, and that the service saves money overall.

What is the aim of the EXTEND Study?

Early Intervention in Psychosis (EIP) is currently meant to be given for three years to everyone. After this time, those who are well are discharged to their GP, while those with ongoing symptoms are transferred to the care of a general community mental health team. People often become unwell at this time of change and might benefit from longer treatment with EIP. We also know that some people who are well could possibly have been discharged back to their GP earlier. We want to develop a more tailored approach based on the needs of each individual and understand the health, social, and cost benefits of this approach.

Who is involved in the EXTEND Study?

The EXTEND study is a team of researchers from universities across the UK, led by Professor Belinda Lennox from the University of Oxford and Professor Paul French from Manchester Metropolitan University. The full EXTEND study team is listed in the study team.

Not all members of the study team are involved in the quantitative aspects of the study, and therefore will not be granted access to service user data. Other members of the team are working on qualitative research that will run alongside the data linkage and analysis.

Who is funding the EXTEND study?

The EXTEND Study is funded in full by the National Institute for Health and Care Research (NIHR), as part of their Programme Grants for Applied Research (Ref: NIHR203277).

What is the role of service users and carers in the EXTEND study?

Two of the co-investigators in the EXTEND study team, Veenu Gupta and David Shiers, have experience of psychosis treatment (as a service user and carer respectively). In addition to contributing to the study directly, they co-chair an EXTEND service user and carer Involvement Group (EXTEND-InG), which will meet regularly to oversee and shape the study.

We will also host "town hall" events to offer wider opportunities for participation, and can be contacted directly.

Use of personal data

Where does the data come from?

The National Clinical Audit of Psychosis (NCAP) is an improvement programme commissioned by the Health Quality Improvement Partnership (HQIP) on behalf of NHS England. The audit is run by the Royal College of Psychiatrists (RCPsych), who publish reports on the NCAP data each year. NCAP collects data on the quality of care delivered to people with FEP. This includes individual-level data on demographics (e.g. age, gender, ethnicity), and receipt of each of the NICE-approved treatments and interventions that are required to be delivered as part of standard EIP care.

The NCAP will be linked with the Mental Health Services Data Set (MHSDS) and the Hospital Emergency Statistics (HES), both of which are controlled by NHS Digital. This includes administrative information on care provided by NHS mental health providers and hospitals. More information on the data collected by NHS Digital for research and planning is available on the NHS website.

Why is this data being used in the Extend study?

The aim of the EXTEND study is to assess whether alternative durations of EIP care, for example through a more personalised approach, can benefit individuals experiencing FEP. By identifying differences between people who receive longer or shorter EIP treatment, we can explore whether differences in length of EIP care lead to different outcomes. We will also find out how differences in duration of EIP influence the short- and long-term cost-effectiveness of the service. By linking the the National Clinical Audit of Psychosis routinely collected NHS data, we will create a dataset that is representative of the entire population of people with psychosis in England. The information collected by the NCAP and NHS Digital will also allow us to control for underlying statistical differences between individuals receiving shorter and longer EIP care.

How do I know if my data is being used in this study?

Your data will be used in this study if your records were reviewed as part of the National Clinical Audit of Psychosis (NCAP) in 2018, 2019 or 2020.

The NCAP is collected by the Royal College of Psychiatrists (RCPsych) on behalf of the Healthcare Quality Improvement Partnership (HQIP). To select the sample included in the NCAP for each year, all NHS Trusts providing Early Intervention in Psychosis (EIP) services in England were asked to identify all individuals under EIP caseloads in their Trust. The NCAP then selected a random sample of up to 100 service users per team from each participating Trust. Where an EIP team had fewer than 100 service users on its caseload, all service users in that team were included in the audit. All 152 EIP teams in England collected and returned audit data. This means that if your records were selected by this method, your data will be included in the EXTEND study.

If you would prefer that your data not be used in the EXTEND study, you can opt out.

You can also opt out of the NCAP by contacting the Royal College of Psychiatrists, or simply check whether your records have been collected without opting out.

You can opt out from any linking to NHS Digital data, including for the EXTEND study, using the National data opt-out.

What is happening to individual data as part of the study?

The use of data in this study has been separated into two distinct stages to minimise the access to personal identifiable data (i.e. data that could be used to identify an individual, such as their age or NHS Number).

Stage 1: Matching NCAP to NHS Digital data

Royal College of Psychiatrists (who hold the NCAP data on behalf of HQIP) will send the NHS Numbers, age, gender and partial postcode of all individuals in each year of the NCAP to NHS Digital, along with a pseudonymous key that Royal College of Psychiatrists (RCPsych) will generate.

NHS Digital will match the cohort of NCAP data they have received to their own records of personal identifiable information. This will produce a linking of NHS Digital identifiers to the NCAP pseudonymous key.

Stage 2: Linking de-identified NCAP and NHS Digital data

De-identified data will be linked and analysed using the pseudonymous key in a secure environment operated by the Office of National Statistics (ONS), as part of its Secure Research Service (SRS).

The Royal College of Psychiatrists will transfer de-identified data from the NCAP (i.e. data without any personal identifiers) to the ONS, along with the pseudonymous key it previously shared with NHS Digital. NHS Digital will also transfer de-identified data from HES and MHSDS along with the same pseudonymous key to the ONS. Researchers from the EXTEND team will then be able to link the NCAP, MHSDS and HES datasets at the patient level on the basis of the pseudonymous key, and conduct the statistical analysis necessary to answer the research questions of the EXTEND study.

How are we protecting individual data in the EXTEND study?

The study is designed to ensure no new access to any of the personal identifiable data used for matching other than to NHS Digital. Access to data on EIP care and outcomes with identifying data removed will be available only to members of the EXTEND study team, who will only be able to access the data through a strictly controlled environment. No information from individual records, identifiable or otherwise, will be published at any point as part of this study.

What is the legal basis for processing this data?

The legal basis for the processing and storage of personal data in this study is 'a task in the public interest' Article 6(1)(e) UK GDPR. The legal basis for processing special category data is 'public interest, scientific or historical research purposes or statistical purposes' Article 9(2)(j) UK GDPR, in accordance with Article 89(1) UK GDPR (as supplemented by section 19 Data Protection Act 2018).

The University of Oxford, based in the United Kingdom, as sponsor, is the data controller. This means that we, as University of Oxford researchers, are responsible for looking after the information received and using it properly. Research is a task that we perform in the public interest. We will use the minimum information possible. Data protection regulation provides you with control over your personal data and how it is used. Further information about your rights with respect to your personal is available at

What ethical approvals are required to process this data?

This study has been considered and approved by an NHS Health Research Authority (HRA) Research Ethics Committee (REC). In addition, the sharing of personal identifiable data for the purposes of matching has been considered and approved by the HRA Confidentiality Advisory Group (CAG).

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