International Surgical Outcomes Study: Long-term survival & healthcare utilisation

In term In term in the September 2026 edition: the latest version runs to 16 January 2027.

Reference: DARS-NIC-68740-X7R2N
Current version: v3.3
Term of current version: 17 January 2024 to 16 January 2027
Start date: 10 July 2019
Data controller: Sole Data Controller
Commercial purposes: No
Sublicensing: No
Files released to date: 5

Why the data was released

Objective for processing

The objective for processing these data is to complete studies related to the International Surgical Outcomes Study (ISOS) UK Cohort that require mortality data. The mortality data will allow Barts Health NHS Trust to determine the long-term survival following surgery.

As the team are performing scientific research at a public institution, the legal basis for processing personal data for this purpose at Barts falls under Article 6(1)(e) of the General Data Protection Regulations (GDPR), i.e., “a task carried out in the public interest”. It also falls under Article 9(2)(j), “processing is necessary for archiving purposes in the public interest, scientific or historical research purposes or statistical purposes”. These legal bases are also applicable because detailed epidemiology of surgery, particularly healthcare need after surgery, is vital for policymakers to support planning. This is very timely as surgical care recovers following disruption caused by the COVID-19 pandemic. Understanding and describing the outcomes patients experience after surgery is clearly in the public interest as demonstrated by the James Lind Priority Setting Partnership.

The European Surgical Outcome Study (EuSOS) was completed in 2012 and is completely separate to this study.

The International Surgical Outcomes Study (ISOS) was a separate study completed in 2014. This Data Sharing Agreement relates to the long-term follow up of the International Surgical Outcomes Study (ISOS) UK Cohort. The team are performing a survival analysis of patients recruited in the UK during ISOS. The main International Surgical Outcomes Study completed in 2014 identified that patients suffering complications were far more likely to die than those who did not. This study will be exploring the long term survival of those who have had surgery and will provide further evidence to support ongoing research in this field.

The other phases of the International Surgical Outcomes Study have been completed. The aim for the processing of mortality data is to answer what the long-term survival is following surgery and how this differs for those suffering complications. The team anticipates the long-term survival data being used in a main analysis of the whole dataset and will consider further sub-group analyses as appropriate.

The purpose of the project is to obtain mortality and hospital episode statistics (HES) data for patients who consented to linkage in the International Surgical Outcomes Study and to describe the long-term survival of these patients. The team requires record level data, pseudonymised by unique ISOS study ID, to cover a follow up period of 3 years. National death data is required as patients may be treated in a different geographical location to their area of residence. Data is only requested for ISOS cohort (7045). Previously, only mortality data had been requested. Going forward, HES APC data will also be disseminated to BARTS. Because of this, work so far has been focused around the mortality data. The patterns that have emerged from the ongoing work indicate that the burden of hospital readmission is very high among some surgical patients. BARTS now wish to understand how complications suffered in the immediate postoperative period associate with long-term survival using the HES APC data requested. This has always been the plan for the work; there has been no change to the purpose of the overall project. The decision was made to initially focus work on the mortality data because of initial issues with the validity of consent. This has now been sorted, hence the current request to add HES APC data to the data request. The patterns that have emerged from ongoing work indicate that the incidence of hospital readmission is very high among some surgical patients. BARTS Health NHS Trust would like to understand how complications suffered in the immediate postoperative period associate with long-term survival.

Only the minimum number of fields required to conduct this study have been requested. The HES APC data has also been minimised to contain pseudonymised data only.

There are no other alternative, less intrusive ways to determine the long-term survival of this patient cohort. HES data will be used to explore the accuracy of HES codes in capturing postoperative complications and to map the postoperative healthcare resource requirements patients have.

This agreement has a mixed approach to the common law duty of confidentiality:

1) Consent from first year of follow up (confirmed by CAG).

2) Section 251 for the following two years of follow up.

Section 251 support has been obtained and maintained. The Confidentiality Advisory Group have confirmed that the study consent material was valid for the purposes of linkage for the first year, and section 251 support has been obtained for a further 2 years of follow up to enable the team to obtain data pertaining to the three-year data of participants enrolled in ISOS. Although this CAG approval was granted at the time of a previous version of this agreement, which was for mortality data only, the CAG support also included HES data, which is being requested in this amendment. CAG have been notified of this amendment to request HES data and have confirmed that this remains within the scope of their original approval.

Other NHS Trusts in England recruited patients to the study, but the study is led by Barts Health NHS Trust and all data is held by this Trust. Barts Health NHS Trust are the sole Data Controller who also process data. National Institute for Health Research (NIHR) are funders of the ISOS study. No other organisations have any say in the purpose of data processing and no other organisations have access to the data requested under this agreement.

Ethical approval (to enable support under section 251 NHS Act 2006, ref:18/YH/0310) is in place and has been updated to include support for obtaining hospital episode statistics data.

Barts Health NHS Trust believe that the risk of harm by dissemination is minimal, and that informing patients, clinicians, researchers and policymakers of the long-term survival or resource utilisation following surgery will lead to further improvements in care.

Processing activities

The steps to be performed to process the data under this agreement are as follows:

a. Investigators at 110 hospitals in England have already entered data onto a secure online e-CRF for the ISOS study. Data entered into the e-CRF includes baseline patient characteristics (such as presence of chronic diseases), surgical features (such as procedure undertaken), perioperative events (such as admission to critical care following surgery), and in-hospital outcomes (such as the occurrence of complications in the immediate postoperative period).

b. The ISOS study team hold study data including patient identifiable information.

c. The ISOS study team will remove study data to create a dataset with only patient identifiers and the ISOS ID. The patient identifiable fields are: Name, date of birth, sex, and postcode.

d. The ISOS study team created a pseudonymised dataset with study data and ISOS ID, but no other patient identifiers.

e. The identifiable dataset was transferred to NHS Digital using a secure method of transfer.

f. NHS England have already linked this data to mortality data and flagged this cohort.

As such, for the purposes of this application amendment, the following steps are necessary:

g. NHS England retrieve the flagged cohort and identify all HES admitted patient care records in relevant time periods.

h. NHS England will transfer the linked dataset to the ISOS study team at Barts Health NHS Trust, identifiable only by the ISOS ID.

i. The ISOS Study team will combine the ISOS study data set with the HES data, using the ISOS ID.

j. Pseudonymised data will be kept separately from identifiable data and HES data will not be linked back to identifiable data.

k. ISOS Study team will complete the statistical analyses using the pseudonymised data set. Only aggregated statistical outputs, meeting current statistical disclosure control standards, will leave the Barts Health Trust through publication of results.

l. The results of the sub-studies will be disseminated via peer-review publication and at academic conferences/meetings.

The purpose of the data analyses referred to above (point k) is as follows:

1. To explore the association between complications and subsequent hospital readmissions, specifically stratifying the cohort by the type of infection suffered. Multivariable regression modelling will be used to account for plausible confounders.

2. To estimate the tariff paid for each surgical episode in the ISOS dataset. This will then be compared to the cost of complications, estimated using excess length of stay associated with complications. Modelling approaches will be considered, including a beta-geometric model.

No linkage other than that described within the agreement is permitted and no further data linkage will be undertaken.

Re-identification is not permitted under this data sharing agreement.

The study team is located at Barts Health NHS Trust. All of the team are substantively employed by Barts Health NHS Trust, except for the Chief Investigator who has a substantive contract with Queen Mary University of London and an Honorary contract with Barts Health NHS Trust. All members of the study team have information governance training and are Good Clinical Practice trained.

All data disseminated under this agreement will be processed and stored at Barts NHS Trust. No data is to be transferred stored or processed at QMUL. Data will be held in a secure file on the Barts Health Computer network. This will be accessible only to named members of the research team. This can be accessed on site, or via secure virtual private network and via password protected accounts assigned to named team members. All data is stored on Barts Health servers. The Barts Health computing network is compliant with existing information security/governance requirements.

NHS England reminds all organisations party to this agreement of the need to comply with the Data Sharing Framework Contract requirements, including those regarding the use (and purposes of that use) by “Personnel” (as defined within the Data Sharing Framework Contract i.e.: employees, agents and contractors of the Data Recipient who may have access to that data).

Only three years follow up data is permitted from when the study commenced in 2014.

Expected output

The following outputs will be produced as a result of the data processing;

1. Reports for funding bodies, Confidentiality Advisory Group and the Research Ethics Committee.

2. The team anticipates at least one submission to a high-impact peer reviewed journal, e.g., British Journal of Anaesthesia. Further pre-specified subgroup analysis plans will be considered including a further investigation of specific complications.

3. The team anticipates presenting the findings to local groups of interest (including anaesthesia & surgical specialties).

4. The team anticipates presenting the results at relevant scientific conferences, e.g., Evidence Based Perioperative Medicine Congress (London).

5. Aggregated data with small numbers suppressed will be made available on the ISOS study website so that participants and interested parties are able to review.

All outputs will contain results in aggregated format only. Small numbers will be suppressed in line with the HES Analysis Guide. Record level information will not be released to any third party.

The team have strong links with the Royal College of Anaesthetists Patient and Public Involvement group who will promote the findings from the study amongst its networks of patients and the public. Additionally, the team are involved in the Perioperative Medicine Programme at the Royal College of Anaesthetists and would anticipate these results impacting on policy recommendations made by this important group. The team will approach relevant policymakers should any results be of particular interest to this group.

Results will be published on the ISOS website, and the team will disseminate through existing channels to professional societies (Royal College of Anaesthetists, Royal College of Surgeons), interested patient groups (including the Patient, Carer and Public Involvement group at the Royal College of anaesthetists) and presentations to professional groups at conferences/talks. These presentations will be either in the form of webcasts, posters, or presentations.

It is anticipated that findings of this work may be influential on further research exploring long-term outcomes after surgery which is currently a very poorly researched field.

The first manuscript from this dataset has already been published, a target date of publication for dataset including HES would be within 6 months of data receipt.

Update 03/01/2024- Using the data linked it was found that socioeconomic deprivation is strongly associated with worse long-term survival after surgery. This important finding was published in the British Journal of Anaesthesia. The Data Controller is undertaking an analysis of how complications in the immediate post-operative period lead to long term death. The Data Controller will further explore this using more detailed hospital episode statistics records with the aim of identifying features that will support improved patient care.

Expected measurable benefits

To date, little information describing the long-term outcomes of surgical patients in England has been published. A recent study by the Trust suggests that most deaths among surgical patients occur among those with chronic diseases, and that these diseases are associated with reduced long term survival (https://pubmed.ncbi.nlm.nih.gov/34949439/). The Trust have also completed analyses of local level datasets which indicate that patients have a substantial increase in healthcare use in the immediate 6-12 months after surgery, but need to use national data to understand how generalisable these findings are. The Trust anticipate this research to be hypothesis-generating, thus the benefit to wider health and social care is by identifying potential health problems and raising awareness of these. It is hoped this will add to a body of evidence to further research in this area to address potential problems, leading to improvement in health. Around 5.1 million patients each year have surgery in the NHS, and there is a huge potential to benefit these groups with further research.

This research aims to better understand the long-term benefits and potential harms of surgery, as well as the human and financial cost of providing surgery within the NHS. The following groups could benefit:

• Patients undergoing surgery

• Clinicians (anaesthetists and surgeons)

• NHS Hospital Trusts

• Non-NHS healthcare organisations

• Researchers

Dissemination is in the public interest as it will provide insights into the risks of surgery and those patients at particular risk of death after surgery. This will potentially lead to improvements in care, which is within the public interest.

The outputs will provide robust figures describing survival after surgery and therefore achieve the stated purpose.

This final project of ISOS will provide important context for earlier studies, and fuel further research into this important subject area. These have been published in a number of journals and explored a number of important areas including the use of critical care after surgery, how acute kidney damage associates with poor outcomes after surgery and the use of simple interventions, like checklists, to improve outcome. Surgery is often considered successful by healthcare professionals if a patient survives until hospital discharge. As a result, the majority of surgical research studies stop collecting data after hospital discharge or until 30-days post-surgery. However, evidence from the USA suggests that the presence of any complications after surgery, even minor ones, can reduce long-term survival.

This has not been demonstrated in a UK cohort, but the results are expected to be similar. Furthermore, feedback from surgical patients suggests that most people undergoing surgery expect to survive to hospital discharge and would only consider the surgery successful if they return to a certain level of pre-morbid function. Therefore, there is a gap between patient expectation of surgery and the evidence from the majority research studies about the long-term results of surgery. This study aims to describe the patterns of survival up to three years after surgery in the UK. This could lead to changes in the way that surgery is planned or delivered and could ultimately benefit patients undergoing surgery.

The target date for completion of projects under the amended application would be 31st June 2026.

The COVID-19 pandemic has starkly highlighted the disadvantage in health outcomes suffered by patients from socioeconomically deprived backgrounds. The data complements this finding and suggest that this effect is not restricted to patients with COVID-19 (e.g. Socioeconomic deprivation and long-term outcomes after elective surgery: analysis of prospective data from two observational studies. (https://pubmed.ncbi.nlm.nih.gov/33220938/)). It is anticipated that the findings will contribute to policy change to improve outcomes for these vulnerable patient groups.

Ongoing studies should determine the cost and long-term survival associated with complications suffered after surgery. This information is vital to enable policymakers to balance the cost of interventions to reduce these complications, and the benefits these interventions may yield.

Benefits reported so far

To date, a paper has been published demonstrating the association between socioeconomic group and long-term survival. Current risk calculators overlook this important risk factor, and this is being incorporated into the ongoing risk modelling in another data set. By highlighting the poorer outcomes experienced by patients from deprived areas, clinicians and policy makers can ensure they carefully consider how existing policies may influence outcomes.

Datasets on the current version

Legal basis for provision: Consent (Reasonable Expectation); Health and Social Care Act 2012 - s261 - 'Other dissemination of information'; Consent (Reasonable Expectation); Health and Social Care Act 2012 – s261(7)

Datasets approved under DARS-NIC-68740-X7R2N-v3.3
Dataset	Type of data	Sensitivity	Frequency	Confidential data
Hospital Episode Statistics Admitted Patient Care (HES APC)	Identifiable	Non-Sensitive	One-Off	Mixture of confidential data flow(s) with consent and flow(s) with support under section 251 NHS Act 2006
MRIS - Cause of Death Report	Identifiable	Sensitive	One-Off	Mixture of confidential data flow(s) with consent and flow(s) with support under section 251 NHS Act 2006
MRIS - Flagging Current Status Report	Identifiable	Sensitive	One-Off	Mixture of confidential data flow(s) with consent and flow(s) with support under section 251 NHS Act 2006

Files released

Files released counts only files released externally by DARS. Access granted in NHS England's own systems, such as its Secure Data Environment, is not included.

Patient opt-outs were applied to all 5 files released under this agreement, across every version. About opt-outs

No files recorded as released under the current version. 5 were released under earlier versions, shown in the version history.

Version history

The register lists each renewal of this agreement as a separate row. This site has 4 versions.

DARS-NIC-68740-X7R2N-v3.3 17 January 2024 to 16 January 2027

Title: International Surgical Outcomes Study: Long-term survival & healthcare utilisation
Commercial: No
Sublicensing: No
Datasets: 3
Files released: 0

Datasets: Hospital Episode Statistics Admitted Patient Care (HES APC); MRIS - Cause of Death Report; MRIS - Flagging Current Status Report

What changed from DARS-NIC-68740-X7R2N-v2.5

Text removed is ~~struck through~~; text added is underlined. Unchanged paragraphs are summarised rather than repeated.

Fields changed from DARS-NIC-68740-X7R2N-v2.5
Field	Was	Became
Title	~~MR1486 - International Surgical Outcomes Study: Long-term survival & healthcare utilisation~~	International Surgical Outcomes Study: Long-term survival & healthcare utilisation
Start date	~~2022-04-01~~	2024-01-17
End date	~~2024-03-31~~	2027-01-16

Objective for processing

[6 paragraphs unchanged] Only the minimum number of fields required to conduct this study have been requested. The HES APC data ~~to be disseminated going forward~~ has also been minimised to contain pseudonymised data only. [8 paragraphs unchanged]

Processing activities

[7 paragraphs unchanged] f. NHS ~~Digital~~ England have already linked this data to mortality data and flagged this cohort. [1 paragraph unchanged] g. NHS ~~Digital~~ England retrieve the flagged cohort and identify all HES admitted patient care records in relevant time periods. h. NHS ~~Digital~~ England will transfer the linked dataset to the ISOS study team at Barts Health NHS Trust, identifiable only by the ISOS ID. [11 paragraphs unchanged] NHS ~~Digital~~ England reminds all organisations party to this agreement of the need to comply [31 words unchanged] contractors of the Data Recipient who may have access to that data). [1 paragraph unchanged]

Expected output

[11 paragraphs unchanged] Update 03/01/2024- Using the data linked it was found that socioeconomic deprivation is strongly associated with worse long-term survival after surgery. This important finding was published in the British Journal of Anaesthesia. The Data Controller is undertaking an analysis of how complications in the immediate post-operative period lead to long term death. The Data Controller will further explore this using more detailed hospital episode statistics records with the aim of identifying features that will support improved patient care.

Expected measurable benefits

[11 paragraphs unchanged] The target date for completion of projects under the amended application would be ~~1st January 2023.~~ 31st June 2026. [2 paragraphs unchanged]

Benefits reported

[1 paragraph unchanged] ~~Due to the COVID-19 pandemic, the anticipated yielded benefits are yet to be realised, but it is hoped that these benefits will become apparent soon as surgical care resumes.~~

DARS-NIC-68740-X7R2N-v2.5 1 April 2022 to 31 March 2024

Title: MR1486 - International Surgical Outcomes Study: Long-term survival & healthcare utilisation
Commercial: No
Sublicensing: No
Datasets: 3
Files released: 3

Datasets: Hospital Episode Statistics Admitted Patient Care (HES APC); MRIS - Cause of Death Report; MRIS - Flagging Current Status Report

What changed from DARS-NIC-68740-X7R2N-v1.2

Text removed is ~~struck through~~; text added is underlined. Unchanged paragraphs are summarised rather than repeated.

Fields changed from DARS-NIC-68740-X7R2N-v1.2
Field	Was	Became
Title	~~MR1486 - International Surgical Outcomes Study: Long-term survival.~~	MR1486 - International Surgical Outcomes Study: Long-term survival & healthcare utilisation
Start date	~~2019-07-10~~	2022-04-01
End date	~~2022-07-09~~	2024-03-31
MRIS - Cause of Death Report: legal basis	~~Health and Social Care Act 2012 – s261(7)~~	Consent (Reasonable Expectation); Health and Social Care Act 2012 – s261(7)
MRIS - Flagging Current Status Report: legal basis	~~Health and Social Care Act 2012 – s261(7)~~	Consent (Reasonable Expectation); Health and Social Care Act 2012 – s261(7)

Datasets: + Hospital Episode Statistics Admitted Patient Care (HES APC)

Objective for processing

The objective for processing these data ~~are~~ is to complete studies related to the International Surgical Outcomes Study (ISOS) UK [9 words unchanged] allow Barts Health NHS Trust to determine the long-term survival following surgery. As the team are performing scientific research at a public institution, the [10 words unchanged] Barts falls under Article 6(1)(e) of the General Data Protection Regulations (GDPR), ~~i.e.~~ i.e., “a task carried out in the public interest”. It also falls under [8 words unchanged] in the public interest, scientific or historical research purposes or statistical purposes”. These legal bases are also applicable because detailed epidemiology of surgery, particularly healthcare need after surgery, is vital for policymakers to support planning. This is very timely as surgical care recovers following disruption caused by the COVID-19 pandemic. Understanding and describing the outcomes patients experience after surgery is clearly in the public interest as demonstrated by the James Lind Priority Setting Partnership. [1 paragraph unchanged] The International Surgical Outcomes Study (ISOS) was a separate study completed in 2014. This ~~data agreement~~ Data Sharing Agreement relates to the ~~long term~~ long-term follow up of the International Surgical Outcomes Study (ISOS) UK Cohort. The [10 words unchanged] the UK during ISOS. The main International Surgical Outcomes Study completed in ~~2014,~~ 2014 identified that patients suffering complications were far more likely to die than those who ~~didn’t.~~ did not. This study will be exploring the long term survival of those who have had ~~surgery,~~ surgery and will provide further evidence to support ongoing research in this field. The other phases of the International Surgical Outcomes Study have been completed. The aim for ~~this~~ the processing of mortality data is to answer what the long-term survival is following surgery [17 words unchanged] in a main analysis of the whole dataset and will consider further ~~subgroup~~ sub-group analyses as appropriate. The purpose of the project is to obtain mortality and hospital episode statistics (HES) data for patients who consented to linkage in the International Surgical Outcomes [47 words unchanged] their area of residence. Data is only requested for ISOS cohort (7045). ~~There are no other alternative, less intrusive ways~~ Previously, only mortality data had been requested. Going forward, HES APC data will also be disseminated to ~~determine~~ BARTS. Because of this, work so far has been focused around the mortality data. The patterns that have emerged from the ongoing work indicate that the burden of hospital readmission is very high among some surgical patients. BARTS now wish to understand how complications suffered in the immediate postoperative period associate with long-term survival using the HES APC data requested. This has always been the plan for the work; there has been no change to the purpose of ~~this patient cohort.~~ the overall project. The decision was made to initially focus work on the mortality data because of initial issues with the validity of consent. This has now been sorted, hence the current request to add HES APC data to the data request. The patterns that have emerged from ongoing work indicate that the incidence of hospital readmission is very high among some surgical patients. BARTS Health NHS Trust would like to understand how complications suffered in the immediate postoperative period associate with long-term survival. Only the minimum number of fields required to conduct this study have been requested. The HES APC data to be disseminated going forward has also been minimised to contain pseudonymised data only. There are no other alternative, less intrusive ways to determine the long-term survival of this patient cohort. HES data will be used to explore the accuracy of HES codes in capturing postoperative complications and to map the postoperative healthcare resource requirements patients have. [3 paragraphs unchanged] Section 251 support has been ~~obtained.~~ obtained and maintained. The Confidentiality Advisory Group have confirmed that the study consent material was [23 words unchanged] follow up to enable the team to obtain data pertaining to the ~~three year survival~~ three-year data of participants enrolled in ISOS. Although this CAG approval was granted at the time of a previous version of this agreement, which was for mortality data only, the CAG support also included HES data, which is being requested in this amendment. CAG have been notified of this amendment to request HES data and have confirmed that this remains within the scope of their original approval. Other NHS Trusts in England recruited patients to the study, but the study is led by Barts Health NHS Trust and all data is held by ~~the~~ this Trust. Barts Health NHS Trust are the sole Data Controller who also process data. National Institute for Health Research (NIHR) are funders of the ISOS study. No other organisations have any say in the purpose of data processing and no other organisations have access to the data requested under this agreement. ~~The ethical~~ Ethical approval (to enable support under section 251 NHS Act 2006, ref:18/YH/0310) ~~raised no new ethical concerns.~~ is in place and has been updated to include support for obtaining hospital episode statistics data. ~~There is no~~ Barts Health NHS Trust believe that the risk of harm by ~~dissemination,~~ dissemination is minimal, and that informing patients, clinicians, researchers and ~~policy-makers~~ policymakers of the long-term survival or resource utilisation following surgery will lead to further improvements in care.

Processing activities

The administrative study sponsor organisation for the International Surgical Outcomes Study (ISOS) study was the Queen Mary University of London (QMUL). Before starting the projects outlined in this ~~agreement~~ Agreement, the mortality data ~~set~~ was transferred to Barts Health NHS Trust from QMUL. Barts Health NHS Trust are the data controller organisation for this ~~agreement~~ Agreement and projects outlined in it. Record-level mortality linked data will not be transferred outside of Barts Health NHS Trust. The steps to be performed to process the data under this agreement is are as follows: a. Investigators at 110 hospitals in England have already entered data ~~on to~~ onto a secure online e-CRF for the ISOS study. Data entered into the e-CRF includes baseline patient characteristics (such as presence of chronic diseases), surgical features (such as procedure undertaken), perioperative events (such as admission to critical care following surgery), and in-hospital outcomes (such as the occurrence of complications in the immediate postoperative period). [1 paragraph unchanged] c. The ISOS study team will remove study data to create a [6 words unchanged] the ISOS ID. The patient identifiable fields are: Name, date of birth, ~~sex~~ sex, and postcode. d. The ISOS study team ~~will also create~~ created a pseudonymised dataset with study data and ISOS ID, but no other patient identifiers. e. The identifiable dataset ~~will be~~ was transferred to NHS Digital using a secure method of transfer. ~~f. NHS Digital will link the patient identifiers to mortality (death) data using the patient identifiers.~~ f. NHS Digital have already linked this data to mortality data and flagged this cohort. ~~g. NHS Digital will then remove patient identifiers, leaving only the ISOS ID and mortality data.~~ As such, for the purposes of this application amendment, the following steps are necessary: ~~h. NHS Digital will transfer the linked dataset to the ISOS study team at Barts Health NHS Trust.~~ g. NHS Digital retrieve the flagged cohort and identify all HES admitted patient care records in relevant time periods. ~~i. The ISOS Study team~~ h. NHS Digital will ~~combine~~ transfer the linked dataset to the ISOS study ~~data set with the mortality linked data, using~~ team at Barts Health NHS Trust, identifiable only by the ISOS ID. ~~j. Pseudonymised data will be kept separately from identifiable data and mortality data will not be linked back to identifiable data.~~ i. The ISOS Study team will combine the ISOS study data set with the HES data, using the ISOS ID. k. ISOS Study team will complete the statistical analyses using the pseudonymised data set. Only aggregated statistical outputs, meeting current statistical disclosure control standards, will be removed from the Barts Health Trust j. Pseudonymised data will be kept separately from identifiable data and HES data will not be linked back to identifiable data. k. ISOS Study team will complete the statistical analyses using the pseudonymised data set. Only aggregated statistical outputs, meeting current statistical disclosure control standards, will leave the Barts Health Trust through publication of results. [1 paragraph unchanged] ~~No linkage, other than that described within the agreement is permitted and no further data linkage will be undertaken.~~ The purpose of the data analyses referred to above (point k) is as follows: 1. To explore the association between complications and subsequent hospital readmissions, specifically stratifying the cohort by the type of infection suffered. Multivariable regression modelling will be used to account for plausible confounders. 2. To estimate the tariff paid for each surgical episode in the ISOS dataset. This will then be compared to the cost of complications, estimated using excess length of stay associated with complications. Modelling approaches will be considered, including a beta-geometric model. No linkage other than that described within the agreement is permitted and no further data linkage will be undertaken. [2 paragraphs unchanged] All data disseminated under this agreement will be processed and stored at [32 words unchanged] only to named members of the research team. This can be accessed ~~only~~ on ~~site~~ site, or via secure virtual private network and via password protected accounts assigned to named team members. All data is stored on Barts Health ~~servers, the~~ servers. The Barts Health computing network is compliant with existing information security/governance requirements. NHS Digital reminds all organisations party to this agreement of the need [17 words unchanged] that use) by “Personnel” (as defined within the Data Sharing Framework Contract ~~ie:~~ i.e.: employees, agents and contractors of the Data Recipient who may have access to that data). Only three years follow up data is permitted from when the ~~data sharing agreement start date.~~ study commenced in 2014.

Expected output

[2 paragraphs unchanged] 2. The team anticipates at least one submission to a high-impact peer reviewed ~~journal. E.g.~~ journal, e.g., British Journal of Anaesthesia. Further pre-specified subgroup analysis plans will be considered including a further investigation of specific complications. [1 paragraph unchanged] 4. The team anticipates presenting the results at relevant scientific ~~conferences e.g.~~ conferences, e.g., Evidence Based Perioperative Medicine Congress (London). 5. ~~Data~~ Aggregated data with small numbers suppressed will be made available on the ISOS study website so that participants and interested parties are able to review. ~~Aggregated data only will be available in the outputs, with small numbers suppressed.~~ All outputs will contain results in aggregated format only. Small numbers will be suppressed in line with the HES Analysis Guide. Record level information will not be released to any third party. The team have strong links with the Royal College of Anaesthetists Patient [43 words unchanged] policy recommendations made by this important group. The team will approach relevant ~~policy-makers~~ policymakers should any results be of particular interest to this group. Results will be published on the ISOS website, and the team will [37 words unchanged] at conferences/talks. These presentations will be either in the form of webcasts, ~~posters~~ posters, or presentations. ~~The~~ It is anticipated that findings of this work ~~will~~ may be ~~highly~~ influential on further research exploring long-term outcomes after surgery which is currently a very poorly researched field. ~~The target dates for publication of the first draft of the manuscript is 01/01/2020.~~ The first manuscript from this dataset has already been published, a target date of publication for dataset including HES would be within 6 months of data receipt.

Expected measurable benefits

To date, ~~no data is available~~ little information describing the ~~long term~~ long-term outcomes of surgical patients in ~~England.~~ England has been published. A recent study by the Trust suggests that most deaths among surgical patients occur among those with chronic diseases, and that these diseases are associated with reduced long term survival (https://pubmed.ncbi.nlm.nih.gov/34949439/). The Trust have also completed analyses of local level datasets which indicate that patients have a substantial increase in healthcare use in the immediate 6-12 months after surgery, but need to use national data to understand how generalisable these findings are. The Trust anticipate this research to be ~~hypothesis generating,~~ hypothesis-generating, thus the benefit to wider health and social care is by identifying [46 words unchanged] there is a huge potential to benefit these groups with further research. [10 paragraphs unchanged] The target date for completion of ~~these~~ projects ~~will~~ under the amended application would be 1st January ~~2020.~~ 2023. The COVID-19 pandemic has starkly highlighted the disadvantage in health outcomes suffered by patients from socioeconomically deprived backgrounds. The data complements this finding and suggest that this effect is not restricted to patients with COVID-19 (e.g. Socioeconomic deprivation and long-term outcomes after elective surgery: analysis of prospective data from two observational studies. (https://pubmed.ncbi.nlm.nih.gov/33220938/)). It is anticipated that the findings will contribute to policy change to improve outcomes for these vulnerable patient groups. Ongoing studies should determine the cost and long-term survival associated with complications suffered after surgery. This information is vital to enable policymakers to balance the cost of interventions to reduce these complications, and the benefits these interventions may yield.

Benefits reported

Not stated in the previous version; added here.

Due to the COVID-19 pandemic, the anticipated yielded benefits are yet to be realised, but it is hoped that these benefits will become apparent soon as surgical care resumes.

Objective for processing

The European Surgical Outcome Study (EuSOS) was completed in 2012 and is completely separate to this study.

Only the minimum number of fields required to conduct this study have been requested. The HES APC data to be disseminated going forward has also been minimised to contain pseudonymised data only.