Information for participants (primarily focused at UK participants)


You are being invited to take part in a research study which aims to help improve the care of patients who undergo surgery in the future. Before you decide, it is important for you to understand why the research is being done and what it will involve. Please take time to read the following information carefully. Talk to others about the study if you wish. Ask us if there is anything that is not clear or if you would like more information.

What is the purpose of this study?

ISOS is a study which is simply recording information about patients undergoing surgery and the care they receive. This information will help us to understand how surgical patients are treated across different healthcare systems worldwide.

Why have I been invited?

This study is taking place in hundreds of hospitals around the world for one week during the spring of 2014. We have chosen you because you are having surgery and will stay in hospital overnight during that week. In the United Kingdom more than 150 hospitals have registered to take part.

Do I have to take part?

No. It is up to you to decide to join the study and your participation is voluntary. You will be asked to sign a consent form if you decide to participate. If you change your mind afterwards you may leave the study at any time – please contact if you would like to do this.

What will happen to me if I take part?

You will not receive any additional treatments or medicines as part of this study. The study simply involves collecting a small amount of information about your treatment during and after surgery. Patients will be followed up until they leave hospital. We will then follow your health status for three years using an NHS database formerly called the Health and Social Care Information Centre (HSCIC), now known as NHS Digital. Your personal information will be shared with NHS Digital to facilitate this (name, date of birth and postcode). Data will be transferred through secure methods to NHS Digital, and no information about the operation or other data collected during the ISOS study will be shared with NHS Digital. They will return the date of death of patients who have died in the three years after surgery.

Will being in this study affect my care?

No. The care you receive will be exactly the same as if the study was not taking place.

What information is collected?

We will record details including your name, age and hospital number, which will allow us to find your information in the NHS database. We will also collect information about your surgery, anaesthesia and your treatment afterwards. The study will combine information collected during your hospital admission with civil registration data (Date of Death and Cause of Death) supplied by NHS Digital on behalf of the Office for National Statistics (ONS)

Who collects this information?

A trained member of NHS staff will collect the information. They are required to adhere to strict codes of confidentiality.

How is this information used?

The information collected about you will be stored on a secure database. Statisticians will analyse the information to understand the care of patients having surgery around the world. Your data is retained for 20 years in line with research regulations.

How secure is this information?

The information is held on a secure computer system and the study has been approved under the Data Protection Act by the lead site, Barts Health NHS Trust.

What are the benefits of taking part?

You will not benefit directly from the study but your participation will help patients undergoing surgery in the future.

What are the disadvantages or risks of taking part?

No. There are no disadvantages of taking part and no changes to your treatment.

Who has reviewed the study?

This study was reviewed by the Yorkshire & The Humber - Humber Bridge Research Ethics Committee (REC). This committee are a group of people who oversee the ethical conduct of research studies. These people are not part of the study team.

Update 16th April 2019; Amended 23 November 2020

The information below is only relevant for patients who consented to enable the study team to follow up their health status via the Health and Social Care Information Centre (now called NHS Digital). Since the end of ISOS, we have applied to receive data from NHS Digital (formerly the Health and Social Care Information Centre; ‘HSCIC’). They hold the data necessary for us to complete the study of long-term survival and healthcare use after surgery. Unfortunately the consent given by patients at the time of enrolment did not meet new standards. As such, we have obtained new approvals to access the data.

Firstly, we obtained a new favourable ethical opinion from the Yorkshire & The Humber Bridge Research Ethics Committee (REC) to enable data transfer under section 251 of the NHS Act 2006. We then obtained support from the Confidentiality Advisory Group (CAG) at the Health Research Authority under section 251 of the NHS Act 2006 to transfer patient information from Barts Health NHS trust to NHS Digital for the purpose of linkage. To find out more about section 251 and the CAG; please see the HRA website

The patient information transferred to NHS Digital will be name, date of birth, sex, postcode and a unique study ID to enable us to link this information regarding death and subsequent hospital admissions to data collected during ISOS. No data about patients’ health condition collected during the study will be transferred to NHS Digital, and data will be transferred by a secure method. This will enable us to determine the number of patients surviving three years after surgery.

Below is some important information regarding our data application.
How can I contact the Data Protection Officer?
They can be contacted by writing to at the following address
Data Protection Officer
Barts Health NHS Trust
3rd Floor
9 Prescot Street
London, E1 8PR
What are the purposes of processing?

The objective for processing these data are to complete studies related to the International Surgical Outcomes Study (ISOS) UK Cohort that require linked civil registration (death) and hospital episode statistics data. This will allow us to determine the long-term survival and healthcare use following surgery amongst the patients enrolled in ISOS.

What is the lawful basis of processing?

Our lawful basis under the Data Protection Act is Article 6(1)(e) as we are performing research in the public interest at a public institution. For handling sensitive health data, our lawful basis is Article 9(2)(j).

What is the legitimate interest for the processing?

We are researchers with a legitimate interest in the outcomes of patients having operations. Our study team have led and published a large number of research studies in this area, this study will be an important component of our work. Specifically, we are interested in the relationship between the long term survival and need for hospital readmission amongst patients who suffer complications after an operation. Understanding the outcomes patients experience after surgery, and potential areas for improvement, are in the public interest.

What categories of personal data are the study team going to obtain?

We will obtain date of death and hospital records from the date of surgery to three years after for participants in ISOS who gave written consent. The source of this data is from the Office for National Statistics and hospital episode statistics, and held by NHS Digital. This will be sent to Barts Health NHS Trust for analysis. No death data will be transferred outside the United Kingdom. We will hold this data for a period of 5 years to enable analysis and distribution of our findings.

What rights do participants have to withdraw consent?

Participants gave written consent at the time of enrolment. Should any patient subsequently wish to be removed from the study, they should contact the research team.

What rights do participants have to lodge a complaint?

Any participant may lodge a complaint with either the data protection officer for Barts Health NHS Trust (contact details above) or the research team (via the ‘contact us’ section).

We plan no automated decision making or profiling work using this death data.

Update 23 November 2020

The first paper has been published following from the above data linkage – please see the findings here:
Socioeconomic deprivation and long-term outcomes after elective surgery: analysis of prospective data from two observational studies - British Journal of Anaesthesia

The study team have amended the above information to access nationally collected healthcare data to determine how patients use healthcare after they have had surgery.

Last updated: 18th May, 2021

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