Virtual Aneurysm Screening Study

This page describes a research project we are planning to undertake with the NHS Abdominal Aortic Aneurysm Screening Programme (the 'NAAASP') where we will use data linkage to find out what would have happened if men were invited for AAA screening by the NAAASP based on their individual risk of having an abdominal aortic aneurysm. This page contains information about the research and will form the Privacy Notice for the research when the project goes ahead.

 

Contents:

 

Introduction

What is the purpose of this research?

How will this research question be answered?

What is the purpose of this privacy notice?

What data will be used?

How will the data be combined?

How can two (pseudo)-anonymised sets of data be joined together?

How will personally identifiable data be protected?

What other information is available?

What if I don’t want my data used in this research?

Who has given approval for this research to go ahead?

 

Introduction:

An abdominal aortic aneurysm (AAA) is a swelling of the main blood vessel in the body, the aorta. If an AAA gets to large it can burst (rupture) and cause dangerous internal bleeding. AAAs can be repaired by having an operation. Operations to repair an AAA once it has ruptured are much higher risk than operations done before an AAA ruptures. This means that most people diagnosed with an AAA are offered surgery to prevent rupture. In the UK around 8000 operations are performed to repair AAAs each year.

One of the main problems with AAAs is that they rarely cause any symptoms before they rupture. This means most patients will not know they have one. AAAs can easily be diagnosed with a simple ultrasound scan. It has been shown that offering an ultrasound scan to men to screen them for AAA can reduce the risk of dying from an AAA by half. All countries in the UK now offer AAA screening to all men in the year of their 65th birthday.

In England, the NHS AAA Screening Programme (the NAAASP) is run by Public Health England, an executive agency of the Department of Health and Social Care. The NAAASP invites about 280,000 men for AAA screening each year. Four out of 5 men attend for screening and about 1 in 100 men who are screened are found to have an AAA. 99 out of 100 men who attend for screening do not have an AAA.

Being invited for screening can cause people to worry about what the result of the test might be. Screening programmes are also expensive for the NHS. It would be beneficial if AAA screening could be targeted towards those men most likely to have an AAA. This would prevent people worrying about the result of a screening test unnecessarily. Any money saved could be used for other parts of the NHS.

One alternative approach to inviting all men for AAA screening is to only invite men for screening if they are at high risk of having an AAA. This approach is used in the United States where only those men who are current or ex-smokers are invited for AAA screening. This reduces the number of men who are screened. It is not known if this approach misses many men with AAAs from the group who are not offered screening.

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What is the purpose of this research?

This research will find out what would happen if AAA screening is only offered to men with known risk factors for AAA such as smoking. The number of men with AAAs who might be missed by a targeted screening programme will be assessed and compared with any benefits from reducing the overall screening programme size.

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How will this research question be answered?

In this research screening results from the NAAASP will be combined with general practice records for each of the men who have been invited for screening. General practice records include information about an individual’s past medical history and smoking status amongst other information. By combining the results of AAA screening with general practice records what would have happened if only men identified as smokers had been invited for AAA screening can be worked out. This work can also be extended to see if there are other risk factors in general practice records that can be used to identify men at high, or low risk of AAA. This information will be used to see if AAA screening can be targeted at groups of men who are at a high risk of having an AAA and, if so, whether such a targeted screening programme would still identify all the men with AAAs.

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What is the purpose of this privacy notice?

This privacy notice has been published because this research will involve analysing screening results and general practice records from men who have previously been screened for AAA in the NAAASP. It is important that information about this work is made publically available.

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What data will be used?

Two sources of data will be used:

1. The NAAASP records the outcomes for all men invited for AAA screening in a large database. Since the programme started in 2009 over 2 million men have been invited for screening. When men are invited for screening the NAAASP records whether they attended for screening or not. In those men who attend for screening the outcome of their screening scan is recorded.

2. NHS Digital, the secure data warehouse for the NHS, can access data from general practitioners. Starting in June 2018, NHS Digital has gathered data from all general practices in the UK about the health backgrounds of men and women eligible for the NHS Health Check. The NHS Health Check invites all men and women between the ages of 40 and 74 for a check-up every 5 years. This data is held by NHS Digital and is planned to be updated once a year.

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How will the data be combined?

Data from the NAAASP and NHS Digital are not routinely combined together in the NHS. Both sets of data are held by separate NHS organizations and cannot be combined without special safeguards and permissions. Neither organization is currently allowed to hold both sets of data in a combined format for the purposes of medical research. To perform this research both datasets will have all identifiable data removed in a process called pseudo-anonymisation (pseudonymisation). The pseudononymised data will be send by a secure electronic link to the research team (currently the University of Leicester) who will join the two sets of data together.

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How can two pseudonymised sets of data be joined together?

Both the NAAASP and NHS Digital use an individual’s NHS number as one form of identification in their datasets. NHS numbers are unique to any one individual. NHS number can be used to link together individual records from each set of data. To protect people’s identity this can be done in such a way that whoever is creating the link cannot identify any of the men in either dataset.

The process that will be used to join the data together is as follows:

The NAAASP will add a meaningless unique identification code to the record for each man invited for screening. The NAAASP will then create two sets of data from this dataset. The first will have all identifiable data removed (name, address, date of birth, NHS number etc.) leaving just the results of screening and the unique identification code for each man in the dataset. This first dataset will be sent to the research team by a secure electronic link. The second set of data created by NAAASP will be a list of NHS numbers for all the men in their data set together with the unique identification code for each man. This second dataset will be sent to NHS Digital by a secure electronic link.

NHS Digital will receive the list of NHS numbers and unique identification code from NAAASP. NHS Digital will use the NHS numbers to add information from general practices to the list. Once complete, the NHS numbers will be deleted from the dataset, leaving a list of general practice information for each man with just the unique identification code attached. NHS Digital will then send this to the research team by secure electronic link.

The research team at the University of Leicester will receive the data from NAAASP and NHS Digital. Because each set of data will have the same unique identification codes for each man the research team will then be able to link together the general practice information from NHS Digital with the screening outcome information from the NAAASP without requiring access to any identifiable data for any of the men in the research study.

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How will personally identifiable data be protected?

The above process does not require any personally identifiable information such as name, address or date of birth to be transferred or shared between any of the parties involved. The only identifier that is transferred between organizations is NHS number (from NAAASP to NHS Digital). This will not be combined with any personal data such as medical records. NHS number on its own is not usually considered to be confidential information or personally identifiable information. NHS Digital already holds NHS numbers for all patients registered with a GP in England so no additional data sharing of NHS number will be taking place.

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What other information is available?

More information about how your personal information is used by the organizations involved in this research is as follows:

NAAASP (Public Health England): (https://www.gov.uk/government/publications/patient-confidentiality-in-nhs-population-screening-programmes/nhs-population-screening-confidential-patient-data#information-shared-by-public-health-england).

NHS Digital NHS Health Check data: https://digital.nhs.uk/services/general-practice-gp-collections/service-information/nhs-health-checks

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What if I don’t want my data used in this research?

If you don’t want your screening information or general practice records to be used in this way then you can opt out. You can either opt out of just this research project or all NHS research and data sharing. This will not affect the care you receive from the NHS. If you just want to opt out of this research project you can either contact Professor Matt Bown or your local AAA screening unit. If you want to opt out of this and other NHS data sharing activities you can find out more information on how to do this at the NHS Choices website (https://www.nhs.uk/your-nhs-data-matters/).

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Who has given approval for this research to go ahead?

Approval for this research will be sought from several authorities.

The NAAASP Research Advisory Committee: This group approves all research that makes use of data from the NAAASP. This committee is made up of managers, doctors, lay members and public health experts from across England.

The Health Research Authority: This research involves the use of individual’s medical records without direct consent. This is undertaken under Section 251 of the Health and Social Care Act 2006. Approval for this work will have to be granted by the Health Research Authority Confidentiality Advisory Group. This research has also been approved by a Research Ethics Committee. These committees approve all medical research in the UK.

NHS Digital: All data sharing agreements with NHS Digital are approved by the Independent Group Advising on the Release of Data. This group will have to approve the release of data from NHS Digital as described here.

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