Revision Hip and Knee Replacements: Evaluation of Clinical, Psychological and Surgical Outcomes
University of Oxford · Academic
In term In term in the September 2026 edition: the latest version runs to 4 May 2028.
- Reference
- DARS-NIC-380650-K4F6X
- Current version
- v3.3
- Term of current version
- 11 April 2025 to 4 May 2028
- Start date
- 12 May 2021
- Data controller
- Sole Data Controller
- Commercial purposes
- No
- Sublicensing
- No
- Files released to date
- 27
Why the data was released
Objective for processing
Hip and knee replacement implants are designed to last a long time, but do not last forever. A revision joint replacement is a procedure to replace an implant that is no longer functioning correctly. These procedures are major surgery because performing a joint replacement can be much more complicated the second (or third) time. This may be due to the presence of infection or formation of scar tissue and loss of bone over time. Around 13,000 revision operations are performed each year in the United Kingdom at a cost of up to £200 million.
Whilst many procedures are successful, previous studies have estimated that up to one-in-three patients do not report any benefit from surgery. The reasons for this are not well understood. The University of Oxford study team are aware of only one study (Baker et al, 2012) that has analysed National Joint Registry (NJR) data linked to Patient reported Outcome Measures (PROMs) for revision joint replacement – reporting on knee procedures only in 797 patients. The proposed study (subject of this agreement) will provide new information on the outcomes from revision hip and knee replacement in a much larger cohort and the factors associated to these outcomes. This information can be used to support shared decision making, to allow patients to make a better-informed decision of whether to undergo revision surgery. Since all patients undergoing revision hip or knee replacement will have experienced primary joint replacement, comparison to primary joint replacement is useful for communication of risks and expected benefits from surgery.
The University of Oxford requires Hospital Episode Statistics (HES), PROMs and Civil Registration (mortality) data for the purpose of an investigation to determine the outcomes from revision hip and knee joint replacement. This study will investigate temporal and geographic variation in these outcomes, and the factors associated to these outcomes. The proposed work will be undertaken by individuals from the Big Health Data Group, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, at the University of Oxford. The work requires the HES, PROMS and mortality data controlled by NHS England to be linked to National Joint Registry (NJR) data - for which Healthcare Quality Improvement Partnership (HQIP) is the data controller - and would be supplied by HQIP’s data processor, Northgate Information Solutions. All linked NJR and NHS Digital data accessible to the team at the University of Oxford will be pseudonymised. Northgate Information Solutions will have no access to NHS England data under this Agreement.
The National Joint Registry is currently responsible for monitoring knee replacements, and commonly collaborates with external groups to investigate outcomes of arthroplasty and relies on GDPR Article 6(1)(e) as the lawful basis to do this. There is public interest from patients undergoing hip and knee arthroplasty to understand the risks and likely benefit of the surgical procedure. This interest has been formalised, for example, the James Lind Alliance Priority Setting Partnership which is made up of patients, carers and clinicians, identified research into revision hip and knee replacement as a key priority. The following key questions generated by this process will be directly addressed in this work:
-What are the most effective ways to organise healthcare and avoid delay to improve the results and patients’ experience of revision knee surgery?
-What factors determine (predict) whether revision knee surgery is likely to work?
-How should one measure the outcomes following revision knee surgery in a way that is meaningful to patients, and is surgery cost effective?
-What are the best forms of surgery to use for revision knee surgery including choice of implant and technique?
The moral and ethical issues include the processing of patient data without consent and the risk of breach of patient confidentiality through transfer and processing of records. These issues have been addressed as follows:
- Research Ethics Committee approval (REC 20/LO/0428)
- CAG Section 251 support (20/CAG/0044)
- Patient and Public Involvement work has been performed at the University of Oxford (with positive feedback) to evaluate patient views on (i) data linkage without consent and (ii) this programme of research.
To minimise risk, University of Oxford has requested pseudonymised records and will also suppress data on small volume groups in dissemination of study results in line with the HES analysis guide.
The data requested includes both the outcomes and predictors of interest. Analysis of these will provide important information on revision hip and knee replacement. The outcomes of interest are patient-reported outcome measures, quality of life measures, mortality, revisions, re-operations and healthcare resource utilisation. The predictors of interest can be classified into patient, surgical, temporal and geographic factors. For example, patient factors include the effects of age, body mass index and pre-existing comorbidities on the outcomes of interest. Surgical factors include the type of procedure and implants used. Temporal and geographic factors include year of surgery, the type of centre (e.g. high volume or low volume caseload) and region.
This study will analyse pseudonymised data from several sources within the NHS that routinely collect information related to revision joint replacement. The University of Oxford will analyse data on patient satisfaction from Patient Reported Outcome Measures; hospital admissions from Hospital Episode Statistics; joint replacements from the National Joint Registry; and mortality from Civil Registration (Deaths). The University of Oxford will analyse this data to describe patient satisfaction and function after revision surgery, medical risks, and the need for further surgery and identify the factors that underpin each of these. The University of Oxford will compare data on revision joint replacement to primary joint replacement.
A DPhil student will form part of the study team. The DPhil student who will collaborate on this work is funded by the Royal College of Surgeons (RCS). The RCS will have no access to the data and no role in its analysis or interpretation. Data from this application will support a chapter on the outcomes of revision knee replacement by the indication for surgery. Other DPhil chapters within this thesis include:
(i) A scoping review of the use of PROMs and their validity for revision knee replacement [submitted for publication];
(ii) Validation of the Oxford Knee Score for revision knee replacement [submitted for publication];
(iii) A systematic review of patient-relevant outcomes following revision knee replacement [in progress].
A description of the data subjects is provided below:
Revision Cohort:
Inclusion-
- Male or Female, aged 18 years or above, AND
- Has undergone revision hip or knee replacement from April 2003 to present, WITH
- Procedure recorded on either HES APC or NJR
Controls:
- Male or Female, aged 18 years or above, AND
- Has undergone primary hip or knee replacement from April 2003 to present, WITH
- Procedure recorded on either HES APC or NJR
This project will address the following specific research questions:
-What are the patient-reported outcomes from revision hip and knee replacement?
-What are the short-term outcomes/complications of revision hip and knee replacement?
-What are the longer-term outcomes from revision hip and knee replacement?
The outcomes of interest have been defined above. For each of these research questions, the proposed work will identify patient, surgeon, institution, temporal and geographic associations to these outcomes.
There is an unmet need to identify the factors which affect whether a patient will benefit from revision surgery and to determine the outcomes from surgery. This proposal will provide evidence to allow patients to fully participate in the decision as to whether to undergo revision surgery. It will create clinical guidelines to support surgeons and will guide improvements in the revision hip and knee replacement pathway.
The datasets requested
-HES APC – This is required to identify primary and revision procedures, and provide data on both outcomes and predictors
-PROMS - This dataset is required to identify patient-reported outcomes and predictors for outcome
-Mortality – This dataset is required to identify mortality associated with revision procedures. This information will be used to communicate risk to patients.
Pseudonymised, patient-level data is required in order to support statistical analyses to identify associations to outcomes.
The University of Oxford has requested data from 1998:
a) To investigate temporal changes in arthroplasty practices. 2003 represents the start of the NJR and data are likely to be relevant to modern arthroplasty practices. A data request from 1998 permits a maximum 5 year look back for participants to allow assessment of pre-existing comorbidity.
b) To provide a sufficiently large dataset to control for a large number of variables as the indications for, and the patients undergoing revision joint replacement are heterogenous. The University of Oxford expects to analyse around 200,000 joint replacement procedures.
This study will analyse both national practices and geographic variations in practice across England.
There are no alternative, less intrusive ways of achieving the purpose. The University of Oxford study team has considered analysis of the candidate datasets alone. However, neither provide sufficiently granular information. For example, use of the NJR dataset alone is limited by:
(i) Poor compliance prior to 2008 leading to incomplete case ascertainment
(ii) Limited information to provide case mix adjustment (only age, sex, BMI and ASA grade)
(iii) Incomplete data on re-revisions (due to changing requirements for NJR reporting) and re-operations (not captured)
(iv) No data on medical complications, or hospital admission factors.
The addition of HES data overcomes these limitations and is expected to contribute additional cases, allow better case-mix adjustment and better capture complications and long-term outcomes. HES data cannot be analysed alone as it provides insufficient granularity on procedural coding for this study (for example, type of revision procedure, implants used, surgeon factors). This study is interested to report national outcomes and analysis of local data would not fulfil this objective. To minimise the required data the proposed work will:
(i) Restrict data to records linked to patients from the NJR cohort, OR
(ii) Patients who match with an OPCS code for a primary or revision hip or knee replacement in the HES APC dataset from 2003 to 2020, OR
(iii) Patients with a hip or knee replacement on the PROMs dataset
The ‘OR’ is important above in order to capture cases not submitted to the National Joint Registry (which has recently changed its definition of revision joint replacement). The proposed work requires a five-year look back from the index joint replacement procedure (primary or revision) on the NJR or HES APC to allow for calculation of Charlson Comorbidity Index (a measure of a patient’s pre-existing health problems, previously used to predict patient’s risk of dying whilst admitted to hospital, and as a predictor of the outcome following joint replacement). All HES, PROMs, and Civil Registration (Deaths) episodes after the index joint replacement procedure are of interest as the proposed work is concerned with both short- and long-term outcomes following surgery.
From the PROMS dataset, the proposed work will exclude records related to non-joint replacement procedures (varicose veins, hernia repairs) as these are not relevant. However, the remaining records and fields are relevant to provide both patient-reported outcomes and complications.
The proposed work would be undertaken by individuals from the Big Health Data Group, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, at the University of Oxford. This work requires HES, PROMS and mortality data controlled by NHS Digital to be linked to National Joint Registry (NJR) data - for which HQIP is the data controller - and would be supplied by HQIP’s data processor, Northgate Information Solutions. All data accessible to the team at the University of Oxford will be pseudonymised. Northgate Information Solutions will have no access to NHS Digital data under this Agreement. The NJR Research Steering Committee and the Healthcare Quality Improvement Partnership Data Access Request Group (HQIP DARG) have both approved this application (NJR REF: RSC 2017/26).
Processing activities
All organisations party to this agreement must 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).
STAGE 1
(Data Flow 1) On behalf of HQIP, Northgate Information Solutions will transfer the following identifying fields into NHS England from the National Joint Registry (NJR):
- NHS number
- Date of Birth
- Gender
- Postcode
- NJR unique identifier (which will be designated the Study ID)
The NJR unique identifier is provided for each eligible patient from the NJR for the purpose of linkage to NHS England held datasets.
NHS Digital will create the study cohort:
(i) NHS Digital will link the NJR cohort to HES using sensitive identifiers
(ii) NHS Digital will identify a cohort of patients with a hip or knee replacement (University of Oxford will send in the operation codes) from HES APC (1998/99 to Latest Available)
(iii) NHS Digital will identify all hip and knee replacement procedures on PROMs
(iv) NHS Digital will combine the cohorts from (i), (ii) and (iii), and extract:
-All HES APC episodes for these patients from 1998/99 to Latest Available
-Civil Registrations (Mortality) for these patients
(Data Flow 2) NHS Digital will transfer to the Big Health Data Group (BHDG) at University of Oxford, pseudonymised records of eligible individuals from HES APC, Civil Registration (deaths) and PROMS. The only pseudonym to be returned is the Study ID.
(Data Flow 3) Northgate Information Solutions will transfer to the Big Health Data Group (BHDG) at University of Oxford, pseudonymised records of eligible individuals from the NJR. These records will include:
- Study ID
- Age at surgery in years
- Gender.
(Data Flow 4) On receipt of the NJR/HQIP and NHS England data sets, the BHDG will be responsible for linking the two data sources. The resulting pseudonymised record-level data-set will be linked, stored and analysed within the BHDG's Data Security Protection Toolkit (DSPT) compliant environment.
STAGE 2
(Data Flow 5)
When the Master Person Service (MPS - an enhanced person-matching algorithm that increases the number of linkable records where incomplete records have been submitted.) is available for PROMs, NHS England will repeat linkage of the NJR to PROMs based on the sensitive identifiers provided in Data Flow 1 (which will have been retained). NHS Digital will supply the PROMS_SERIAL_NO (a unique ID in PROMS) and Study_ID to BHDG in University of Oxford as a separate linkage file.
The University of Oxford is requesting HES APC data for patients found in the NJR cohort AND patients with hip and knee joint replacements not found in the NJR cohort.
There will be no linkage to any publicly available data. There will be no attempt to re-identify individuals from this data-set, and results will be presented at aggregate level with small numbers suppressed in line with the HES Analysis Guide. The linked data set containing data from NHS England will not be accessed by the NJR/HQIP. Only substantive employees of the data controller will have access to the data under this agreement. These employees of the data controller have been appropriately trained in data protection and confidentiality. Within the University of Oxford Big Health Data Group, data is held in the Secure Computing Room, which is access controlled. Data are encrypted and stored in a safe. Data are accessed on non-networked computers.
DATA MINIMISATION:
>Datasets
1. NJR-HES-PROMs-Civil Registrations (Mortality) are requested. It is not possible to reduce the number of datasets because: (i) incomplete case ascertainment of NJR (ii) further granularity is required on patient comorbidities and complications (pre-existing and new) from HES and PROMs datasets (iii) data on mortality is required as a competing risk for implant (re)revision
2. The purpose can be achieved in a less intrusive way by using pseudonymised data.
>Years
3. The proposed study will investigate trends over time in modern arthroplasty practices. As such, data from 1998 is appropriate.
>Filtering
4. The proposed study will investigate geographic trends so geographic narrowing is inappropriate.
5. The proposed study will investigate the effect of patient demographics, so filtering is inappropriate - except data for those under 18 is not required.
6. The proposed study requests data on patients who have received a hip or knee joint replacement and requests filtering on this criterion (using OPCS codes supplied and linkage to the NJR dataset)
>Episodes
7. The study is investigating both the effect of pre-existing comorbidity on outcomes and the development of new comorbidity both in the short-term and long-term (up to 15 years). As such, episodes 5 years prior to joint replacement and all subsequent episodes are relevant.
8. Elective episodes are relevant as they may represent further surgery to the joint replacement or a new comorbidity
9. Maternity and neonatal episodes are not required and have not been requested.
10. Timeframe - Data from 1998 is requested to appropriately investigate trends overtime in modern arthroplasty practices.
Fields
11. Fields have been selected to provide predictors and outcomes of interest. This includes ETHNOS as ethnicity may be a predictor of outcome.
12. Full date of death has not been requested, but month/year has been requested instead to prevent intrusion
Cohorts
13/14. Linkage to NJR cohort is requested AND/OR matching with a pre-specified list of hip and knee replacement OPCS codes
There will be no data linkage undertaken with NHS digital data provided under this agreement that is not already noted in the agreement.
Expected output
The specific outputs from the proposed work can be classified as:
1. Peer reviewed journal publications. This will include original articles on patient-reported outcomes, short term complications and longer term outcomes from revision hip and knee replacements. These publications will be Open Access. A first publication is target at 9 months from data receipt, with further publications at 6 monthly intervals.
2. Conference presentations: The proposed work will be presented at national and international conferences. This is to engage a broad spectrum of surgeons and allied health professionals who practice in or around revision joint replacement surgery across the UK. The British Association of Surgeons of the Knee (BASK) and British Orthopaedic Association (BOA) Annual Meetings in 2021 are targets for presentation of the proposed work.
3. Clinical practice guidelines. The University of Oxford study team work closely with BASK and the BOA and have been involved in recent work to produce British Orthopaedic Association Standards (BOASts) which are guidelines on the management of orthopaedic conditions. The evidence generated from the proposed work will be used to update the BOASTs for revision joint replacement. The target date for this is 2023.
4. Social media engagement with patients, surgeons, researchers and allied health professionals. The NDORMs Twitter account (@ndorms) will be used to announce study progress and results. This is intended to engage patients, surgeons and researchers with research outputs as they are produced.
5. Public reports: A project summary will be provided on the NDORMs study webpage. The proposed work will also produce a summary for the National Joint Registry Annual Report. This first summary is intended for the NJR 19th Annual report in 2022.
6. DPhil thesis. This is intended to be published Open Access in 2023 to provide information on outcomes following revision knee replacement. The DPhil student is funded by the Royal College of Surgeons (RCS). The RCS will have no access to the data and no role in its analysis or interpretation.
7. Patients engagement work: The University of Oxford has already started to involve patients and the public with this proposal and will continue this over the duration of the proposal. The Patient and Public Involvement Strategy for this proposal is as follows:
(i) Establishing key priorities for research on revision joint replacement.
See previous references to James Lind Alliance Priority Setting Partnership work.
(ii) Establishing patient views on data linkage without consent
This has been tested in 4 patients known to the research team (mix of men, women, different ages, from various parts of the country who have had a known problem with an implant after surgery). Patients were chosen as a convenience sample by the Nuffield Orthopaedic Centre, Oxford. 4/4 patients agreed that it would not be practical to contact all patients to obtain consent due to the size of the population. The feedback from all had a common theme: the potential benefits from new information on revision knee replacement meant that it was important for this research to be performed. They were satisfied that opt-out mechanisms were in place should patients wish to do so.
(iii) Establishing patient views on the programme of revision knee replacement research proposed
Telephone interviews have been performed with four patients to describe the proposed research programme. They provided very positive feedback. Some quotes were:
-“This will provide very useful information”
-“I think it can help others in the future, and it seems like a very good idea”
-“I have been through several operations on my knee and there isn’t much information out there for patients like me.”
-“I actually had very good information from Oxford when undergoing my revision knee replacement, and I really wish that information on revision knee replacement was rather better known around the country.”
(iv) Extended PPI work
The University of Oxford is recruiting a PPI group of 8-12 patients who are awaiting or have undergone revision knee replacement. The University of Oxford will explore with this group:
-What factors are important to patients in the decision to undergo revision knee replacement?
-How should outcomes following revision knee replacement be evaluated in a way that is meaningful to patients?
This group is currently being recruited.
(v) Revision arthroplasty study website
This is being set-up. Lay summaries of research will be available on this website.
(vi) Open days
These were held regularly, but are currently paused due to Covid-19, but will be reinstated in-person or virtually within the first year of the project.
All outputs will contain only data that is aggregated with small numbers suppressed in line with the HES Analysis Guide.
Expected measurable benefits
It is hoped that the expected measurable benefits to health and or social care will be:
1. Patients potentially better informed to participate in the decision to undergo revision hip and knee replacement. Patients will hopefully be informed about the observed joint function, quality of life, short-term complications, longer-term outcomes and variations in care following revision joint replacement. It is hoped patients will be informed via social media engagement, public reports and patient engagement work as listed in the section above. The rationale for a broad, multifaceted engagement strategy is to reach as wide a patient audience as possible. Patients undergoing revision joint replacement are heterogenous and whilst many are avidly engaged with social media, many prefer more traditional engagement activities.
2. It is hoped that surgeons will be supported to change practice to deliver evidence-based surgery. Surgeons will hopefully be informed of the findings via journal publications, conference presentations, a DPhil thesis, and communication through social media and the British Orthopaedic Association (BOA). Target dates have been listed in the output strategy above. A broad engagement strategy has been chosen in order to reach as many surgeons and researchers practicing in this are from across the country. For example, the BOA is in regular communication with more than 5,000 members across the UK.
3. It is hoped that NHS commissioners will be supported to promote evidence-based surgery and appropriate resource allocation. There are approximately 13000 revision joint replacement procedures performed each year in the UK. The hypothesis for this work is that some types of procedures or procedures for certain groups of patients may be found to be of limited benefit and as such may be candidates for decommissioning. This may lead to cost savings, and may also mean that patients do not experience procedures with high risks of adverse events for limited or no benefit. This information will be available to care providers and commissioners via outputs 1/2/5 above.
4. It is hoped that there will be improvement in patient reported outcome measures (PROMs) following revision surgery. The NHS routinely collects data on the patient perspective following revision hip and knee replacement as part of the NHS PROMs programme. If this proposal is successful and changes are implemented into practice, then one might expect improvement in PROMs over time.
Benefits reported so far
This programme of research has yielded the following measurable benefits to health and social care to date:
1. Information to support shared decision making between patients and surgeons around revision hip and knee replacement
- Journal publication (Knees= 10.2106/JBJS.23.00251; Hips= Under review)
- R Shiny web application (Knees= https://shiraz-sabah.shinyapps.io/rKA-app/; Hips= Under review)
2. Information to understand the current epidemiology of revision hip and knee replacement in the UK
- Journal publications (Knees= https://doi.org/10.1016/j.joca.2022.08.016; Hips= https://doi.org/10.1136/bmjopen-2023-072462)
3. Information to support National Joint Registry (NJR) Patient Reported Outcome Measures (PROMs) development
- The study team have worked with the NJR and NHS England to better understand linkage of these datasets.
4. An understanding of the projected risk of revision in patients less than 60 years of age in Total Hip Replacements and Total Knee Replacements
Journal publication:
http://doi: 10.1016/S0140-6736(17)30059-4
5. An understanding of the increase in younger patients undergoing hip and knee replacements, with future projections in the UK
Journal publication:
http://doi: 10.1016/j.joca.2014.12.022
Datasets on the current version
Legal basis for provision: Health and Social Care Act 2012 - s261 - 'Other dissemination of information'; National Health Service Act 2006 - s251 - 'Control of patient information'.
| Dataset | Type of data | Sensitivity | Frequency | Confidential data |
|---|---|---|---|---|
| Civil Registrations of Death - Secondary Care Cut | Anonymised - ICO Code Compliant | Sensitive | One-Off | Section 251 NHS Act 2006 |
| HES:Civil Registration (Deaths) bridge | Anonymised - ICO Code Compliant | Non-Sensitive | One-Off | Section 251 NHS Act 2006 |
| Hospital Episode Statistics Admitted Patient Care (HES APC) | Anonymised - ICO Code Compliant | Non-Sensitive | One-Off | Section 251 NHS Act 2006 |
| Patient Reported Outcome Measures (Linkable to HES) | Anonymised - ICO Code Compliant | Non-Sensitive | One-Off | 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 26 of the 27 files released under this agreement, across every version. About opt-outs
No files recorded as released under the current version. 27 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-380650-K4F6X-v3.3 11 April 2025 to 4 May 2028
- Title
- Revision Hip and Knee Replacements: Evaluation of Clinical, Psychological and Surgical Outcomes
- Commercial
- No
- Sublicensing
- No
- Datasets
- 4
- Files released
- 0
Datasets: Civil Registrations of Death - Secondary Care Cut; HES:Civil Registration (Deaths) bridge; Hospital Episode Statistics Admitted Patient Care (HES APC); Patient Reported Outcome Measures (Linkable to HES)
What changed from DARS-NIC-380650-K4F6X-v2.5
Text removed is struck through; text added is underlined. Unchanged paragraphs are summarised rather than repeated.
| Field | Was | Became |
|---|---|---|
| Start date | 2025-04-11 | |
| End date | 2028-05-04 |
Objective for processing
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available.***
[56 paragraphs unchanged]
Expected measurable benefits
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available. ***
[5 paragraphs unchanged]
Benefits reported
[8 paragraphs unchanged] 4. An understanding of the projected risk of revision in patients less than 60 years of age in Total Hip Replacements and Total Knee Replacements Journal publication: http://doi: 10.1016/S0140-6736(17)30059-4 5. An understanding of the increase in younger patients undergoing hip and knee replacements, with future projections in the UK Journal publication: http://doi: 10.1016/j.joca.2014.12.022
Unchanged: Processing activities, Expected output.
DARS-NIC-380650-K4F6X-v2.5 29 April 2024 to 5 May 2025
- Title
- Revision Hip and Knee Replacements: Evaluation of Clinical, Psychological and Surgical Outcomes
- Commercial
- No
- Sublicensing
- No
- Datasets
- 4
- Files released
- 0
Datasets: Civil Registrations of Death - Secondary Care Cut; HES:Civil Registration (Deaths) bridge; Hospital Episode Statistics Admitted Patient Care (HES APC); Patient Reported Outcome Measures (Linkable to HES)
What changed from DARS-NIC-380650-K4F6X-v1.3
Text removed is struck through; text added is underlined. Unchanged paragraphs are summarised rather than repeated.
| Field | Was | Became |
|---|---|---|
| Start date | 2024-04-29 | |
| End date | 2025-05-05 |
Objective for processing
[3 paragraphs unchanged]
The University of Oxford requires Hospital Episode Statistics (HES), PROMs and Civil
[67 words unchanged]
The work requires the HES, PROMS and mortality data controlled by NHS
Digital
England
to be linked to National Joint Registry (NJR) data - for which
[37 words unchanged]
will be pseudonymised. Northgate Information Solutions will have no access to NHS
Digital
England
data under this Agreement.
[53 paragraphs unchanged]
Processing activities
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available. ***
[2 paragraphs unchanged]
(Data Flow 1) On behalf of HQIP, Northgate Information Solutions will transfer the following identifying fields into NHS
Digital
England
from the National Joint Registry (NJR):
[5 paragraphs unchanged]
The NJR unique identifier is provided for each eligible patient from the NJR for the purpose of linkage to NHS
Digital
England
held datasets.
[12 paragraphs unchanged]
(Data Flow 4) On receipt of the NJR/HQIP and NHS
Digital
England
data sets, the BHDG will be responsible for linking the two data
[10 words unchanged]
and analysed within the BHDG's Data Security Protection Toolkit (DSPT) compliant environment.
[2 paragraphs unchanged]
When the Master Person Service (MPS - an enhanced person-matching algorithm that
[5 words unchanged]
records where incomplete records have been submitted.) is available for PROMs, NHS
Digital
England
will repeat linkage of the NJR to PROMs based on the sensitive
[23 words unchanged]
Study_ID to BHDG in University of Oxford as a separate linkage file.
[1 paragraph unchanged]
There will be no linkage to any publicly available data. There will
[24 words unchanged]
the HES Analysis Guide. The linked data set containing data from NHS
Digital
England
will not be accessed by the NJR/HQIP. Only substantive employees of the
[49 words unchanged]
encrypted and stored in a safe. Data are accessed on non-networked computers.
[21 paragraphs unchanged]
Expected output
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available.***
[28 paragraphs unchanged]
Benefits reported
Not stated in the previous version; added here.
This programme of research has yielded the following measurable benefits to health and social care to date:
1. Information to support shared decision making between patients and surgeons around revision hip and knee replacement
- Journal publication (Knees= 10.2106/JBJS.23.00251; Hips= Under review)
- R Shiny web application (Knees= https://shiraz-sabah.shinyapps.io/rKA-app/; Hips= Under review)
2. Information to understand the current epidemiology of revision hip and knee replacement in the UK
- Journal publications (Knees= https://doi.org/10.1016/j.joca.2022.08.016; Hips= https://doi.org/10.1136/bmjopen-2023-072462)
3. Information to support National Joint Registry (NJR) Patient Reported Outcome Measures (PROMs) development
- The study team have worked with the NJR and NHS England to better understand linkage of these datasets.
Unchanged: Expected measurable benefits.
Objective for processing
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available.***
Hip and knee replacement implants are designed to last a long time, but do not last forever. A revision joint replacement is a procedure to replace an implant that is no longer functioning correctly. These procedures are major surgery because performing a joint replacement can be much more complicated the second (or third) time. This may be due to the presence of infection or formation of scar tissue and loss of bone over time. Around 13,000 revision operations are performed each year in the United Kingdom at a cost of up to £200 million.
Whilst many procedures are successful, previous studies have estimated that up to one-in-three patients do not report any benefit from surgery. The reasons for this are not well understood. The University of Oxford study team are aware of only one study (Baker et al, 2012) that has analysed National Joint Registry (NJR) data linked to Patient reported Outcome Measures (PROMs) for revision joint replacement – reporting on knee procedures only in 797 patients. The proposed study (subject of this agreement) will provide new information on the outcomes from revision hip and knee replacement in a much larger cohort and the factors associated to these outcomes. This information can be used to support shared decision making, to allow patients to make a better-informed decision of whether to undergo revision surgery. Since all patients undergoing revision hip or knee replacement will have experienced primary joint replacement, comparison to primary joint replacement is useful for communication of risks and expected benefits from surgery.
The University of Oxford requires Hospital Episode Statistics (HES), PROMs and Civil Registration (mortality) data for the purpose of an investigation to determine the outcomes from revision hip and knee joint replacement. This study will investigate temporal and geographic variation in these outcomes, and the factors associated to these outcomes. The proposed work will be undertaken by individuals from the Big Health Data Group, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, at the University of Oxford. The work requires the HES, PROMS and mortality data controlled by NHS England to be linked to National Joint Registry (NJR) data - for which Healthcare Quality Improvement Partnership (HQIP) is the data controller - and would be supplied by HQIP’s data processor, Northgate Information Solutions. All linked NJR and NHS Digital data accessible to the team at the University of Oxford will be pseudonymised. Northgate Information Solutions will have no access to NHS England data under this Agreement.
The National Joint Registry is currently responsible for monitoring knee replacements, and commonly collaborates with external groups to investigate outcomes of arthroplasty and relies on GDPR Article 6(1)(e) as the lawful basis to do this. There is public interest from patients undergoing hip and knee arthroplasty to understand the risks and likely benefit of the surgical procedure. This interest has been formalised, for example, the James Lind Alliance Priority Setting Partnership which is made up of patients, carers and clinicians, identified research into revision hip and knee replacement as a key priority. The following key questions generated by this process will be directly addressed in this work:
-What are the most effective ways to organise healthcare and avoid delay to improve the results and patients’ experience of revision knee surgery?
-What factors determine (predict) whether revision knee surgery is likely to work?
-How should one measure the outcomes following revision knee surgery in a way that is meaningful to patients, and is surgery cost effective?
-What are the best forms of surgery to use for revision knee surgery including choice of implant and technique?
The moral and ethical issues include the processing of patient data without consent and the risk of breach of patient confidentiality through transfer and processing of records. These issues have been addressed as follows:
- Research Ethics Committee approval (REC 20/LO/0428)
- CAG Section 251 support (20/CAG/0044)
- Patient and Public Involvement work has been performed at the University of Oxford (with positive feedback) to evaluate patient views on (i) data linkage without consent and (ii) this programme of research.
To minimise risk, University of Oxford has requested pseudonymised records and will also suppress data on small volume groups in dissemination of study results in line with the HES analysis guide.
The data requested includes both the outcomes and predictors of interest. Analysis of these will provide important information on revision hip and knee replacement. The outcomes of interest are patient-reported outcome measures, quality of life measures, mortality, revisions, re-operations and healthcare resource utilisation. The predictors of interest can be classified into patient, surgical, temporal and geographic factors. For example, patient factors include the effects of age, body mass index and pre-existing comorbidities on the outcomes of interest. Surgical factors include the type of procedure and implants used. Temporal and geographic factors include year of surgery, the type of centre (e.g. high volume or low volume caseload) and region.
This study will analyse pseudonymised data from several sources within the NHS that routinely collect information related to revision joint replacement. The University of Oxford will analyse data on patient satisfaction from Patient Reported Outcome Measures; hospital admissions from Hospital Episode Statistics; joint replacements from the National Joint Registry; and mortality from Civil Registration (Deaths). The University of Oxford will analyse this data to describe patient satisfaction and function after revision surgery, medical risks, and the need for further surgery and identify the factors that underpin each of these. The University of Oxford will compare data on revision joint replacement to primary joint replacement.
A DPhil student will form part of the study team. The DPhil student who will collaborate on this work is funded by the Royal College of Surgeons (RCS). The RCS will have no access to the data and no role in its analysis or interpretation. Data from this application will support a chapter on the outcomes of revision knee replacement by the indication for surgery. Other DPhil chapters within this thesis include:
(i) A scoping review of the use of PROMs and their validity for revision knee replacement [submitted for publication];
(ii) Validation of the Oxford Knee Score for revision knee replacement [submitted for publication];
(iii) A systematic review of patient-relevant outcomes following revision knee replacement [in progress].
A description of the data subjects is provided below:
Revision Cohort:
Inclusion-
- Male or Female, aged 18 years or above, AND
- Has undergone revision hip or knee replacement from April 2003 to present, WITH
- Procedure recorded on either HES APC or NJR
Controls:
- Male or Female, aged 18 years or above, AND
- Has undergone primary hip or knee replacement from April 2003 to present, WITH
- Procedure recorded on either HES APC or NJR
This project will address the following specific research questions:
-What are the patient-reported outcomes from revision hip and knee replacement?
-What are the short-term outcomes/complications of revision hip and knee replacement?
-What are the longer-term outcomes from revision hip and knee replacement?
The outcomes of interest have been defined above. For each of these research questions, the proposed work will identify patient, surgeon, institution, temporal and geographic associations to these outcomes.
There is an unmet need to identify the factors which affect whether a patient will benefit from revision surgery and to determine the outcomes from surgery. This proposal will provide evidence to allow patients to fully participate in the decision as to whether to undergo revision surgery. It will create clinical guidelines to support surgeons and will guide improvements in the revision hip and knee replacement pathway.
The datasets requested
-HES APC – This is required to identify primary and revision procedures, and provide data on both outcomes and predictors
-PROMS - This dataset is required to identify patient-reported outcomes and predictors for outcome
-Mortality – This dataset is required to identify mortality associated with revision procedures. This information will be used to communicate risk to patients.
Pseudonymised, patient-level data is required in order to support statistical analyses to identify associations to outcomes.
The University of Oxford has requested data from 1998:
a) To investigate temporal changes in arthroplasty practices. 2003 represents the start of the NJR and data are likely to be relevant to modern arthroplasty practices. A data request from 1998 permits a maximum 5 year look back for participants to allow assessment of pre-existing comorbidity.
b) To provide a sufficiently large dataset to control for a large number of variables as the indications for, and the patients undergoing revision joint replacement are heterogenous. The University of Oxford expects to analyse around 200,000 joint replacement procedures.
This study will analyse both national practices and geographic variations in practice across England.
There are no alternative, less intrusive ways of achieving the purpose. The University of Oxford study team has considered analysis of the candidate datasets alone. However, neither provide sufficiently granular information. For example, use of the NJR dataset alone is limited by:
(i) Poor compliance prior to 2008 leading to incomplete case ascertainment
(ii) Limited information to provide case mix adjustment (only age, sex, BMI and ASA grade)
(iii) Incomplete data on re-revisions (due to changing requirements for NJR reporting) and re-operations (not captured)
(iv) No data on medical complications, or hospital admission factors.
The addition of HES data overcomes these limitations and is expected to contribute additional cases, allow better case-mix adjustment and better capture complications and long-term outcomes. HES data cannot be analysed alone as it provides insufficient granularity on procedural coding for this study (for example, type of revision procedure, implants used, surgeon factors). This study is interested to report national outcomes and analysis of local data would not fulfil this objective. To minimise the required data the proposed work will:
(i) Restrict data to records linked to patients from the NJR cohort, OR
(ii) Patients who match with an OPCS code for a primary or revision hip or knee replacement in the HES APC dataset from 2003 to 2020, OR
(iii) Patients with a hip or knee replacement on the PROMs dataset
The ‘OR’ is important above in order to capture cases not submitted to the National Joint Registry (which has recently changed its definition of revision joint replacement). The proposed work requires a five-year look back from the index joint replacement procedure (primary or revision) on the NJR or HES APC to allow for calculation of Charlson Comorbidity Index (a measure of a patient’s pre-existing health problems, previously used to predict patient’s risk of dying whilst admitted to hospital, and as a predictor of the outcome following joint replacement). All HES, PROMs, and Civil Registration (Deaths) episodes after the index joint replacement procedure are of interest as the proposed work is concerned with both short- and long-term outcomes following surgery.
From the PROMS dataset, the proposed work will exclude records related to non-joint replacement procedures (varicose veins, hernia repairs) as these are not relevant. However, the remaining records and fields are relevant to provide both patient-reported outcomes and complications.
The proposed work would be undertaken by individuals from the Big Health Data Group, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, at the University of Oxford. This work requires HES, PROMS and mortality data controlled by NHS Digital to be linked to National Joint Registry (NJR) data - for which HQIP is the data controller - and would be supplied by HQIP’s data processor, Northgate Information Solutions. All data accessible to the team at the University of Oxford will be pseudonymised. Northgate Information Solutions will have no access to NHS Digital data under this Agreement. The NJR Research Steering Committee and the Healthcare Quality Improvement Partnership Data Access Request Group (HQIP DARG) have both approved this application (NJR REF: RSC 2017/26).
Expected output
The specific outputs from the proposed work can be classified as:
1. Peer reviewed journal publications. This will include original articles on patient-reported outcomes, short term complications and longer term outcomes from revision hip and knee replacements. These publications will be Open Access. A first publication is target at 9 months from data receipt, with further publications at 6 monthly intervals.
2. Conference presentations: The proposed work will be presented at national and international conferences. This is to engage a broad spectrum of surgeons and allied health professionals who practice in or around revision joint replacement surgery across the UK. The British Association of Surgeons of the Knee (BASK) and British Orthopaedic Association (BOA) Annual Meetings in 2021 are targets for presentation of the proposed work.
3. Clinical practice guidelines. The University of Oxford study team work closely with BASK and the BOA and have been involved in recent work to produce British Orthopaedic Association Standards (BOASts) which are guidelines on the management of orthopaedic conditions. The evidence generated from the proposed work will be used to update the BOASTs for revision joint replacement. The target date for this is 2023.
4. Social media engagement with patients, surgeons, researchers and allied health professionals. The NDORMs Twitter account (@ndorms) will be used to announce study progress and results. This is intended to engage patients, surgeons and researchers with research outputs as they are produced.
5. Public reports: A project summary will be provided on the NDORMs study webpage. The proposed work will also produce a summary for the National Joint Registry Annual Report. This first summary is intended for the NJR 19th Annual report in 2022.
6. DPhil thesis. This is intended to be published Open Access in 2023 to provide information on outcomes following revision knee replacement. The DPhil student is funded by the Royal College of Surgeons (RCS). The RCS will have no access to the data and no role in its analysis or interpretation.
7. Patients engagement work: The University of Oxford has already started to involve patients and the public with this proposal and will continue this over the duration of the proposal. The Patient and Public Involvement Strategy for this proposal is as follows:
(i) Establishing key priorities for research on revision joint replacement.
See previous references to James Lind Alliance Priority Setting Partnership work.
(ii) Establishing patient views on data linkage without consent
This has been tested in 4 patients known to the research team (mix of men, women, different ages, from various parts of the country who have had a known problem with an implant after surgery). Patients were chosen as a convenience sample by the Nuffield Orthopaedic Centre, Oxford. 4/4 patients agreed that it would not be practical to contact all patients to obtain consent due to the size of the population. The feedback from all had a common theme: the potential benefits from new information on revision knee replacement meant that it was important for this research to be performed. They were satisfied that opt-out mechanisms were in place should patients wish to do so.
(iii) Establishing patient views on the programme of revision knee replacement research proposed
Telephone interviews have been performed with four patients to describe the proposed research programme. They provided very positive feedback. Some quotes were:
-“This will provide very useful information”
-“I think it can help others in the future, and it seems like a very good idea”
-“I have been through several operations on my knee and there isn’t much information out there for patients like me.”
-“I actually had very good information from Oxford when undergoing my revision knee replacement, and I really wish that information on revision knee replacement was rather better known around the country.”
(iv) Extended PPI work
The University of Oxford is recruiting a PPI group of 8-12 patients who are awaiting or have undergone revision knee replacement. The University of Oxford will explore with this group:
-What factors are important to patients in the decision to undergo revision knee replacement?
-How should outcomes following revision knee replacement be evaluated in a way that is meaningful to patients?
This group is currently being recruited.
(v) Revision arthroplasty study website
This is being set-up. Lay summaries of research will be available on this website.
(vi) Open days
These were held regularly, but are currently paused due to Covid-19, but will be reinstated in-person or virtually within the first year of the project.
All outputs will contain only data that is aggregated with small numbers suppressed in line with the HES Analysis Guide.
Benefits reported
This programme of research has yielded the following measurable benefits to health and social care to date:
1. Information to support shared decision making between patients and surgeons around revision hip and knee replacement
- Journal publication (Knees= 10.2106/JBJS.23.00251; Hips= Under review)
- R Shiny web application (Knees= https://shiraz-sabah.shinyapps.io/rKA-app/; Hips= Under review)
2. Information to understand the current epidemiology of revision hip and knee replacement in the UK
- Journal publications (Knees= https://doi.org/10.1016/j.joca.2022.08.016; Hips= https://doi.org/10.1136/bmjopen-2023-072462)
3. Information to support National Joint Registry (NJR) Patient Reported Outcome Measures (PROMs) development
- The study team have worked with the NJR and NHS England to better understand linkage of these datasets.
DARS-NIC-380650-K4F6X-v1.3 4 April 2022 to 5 May 2024
- Title
- Revision Hip and Knee Replacements: Evaluation of Clinical, Psychological and Surgical Outcomes
- Commercial
- No
- Sublicensing
- No
- Datasets
- 4
- Files released
- 27
Datasets: Civil Registrations of Death - Secondary Care Cut; HES:Civil Registration (Deaths) bridge; Hospital Episode Statistics Admitted Patient Care (HES APC); Patient Reported Outcome Measures (Linkable to HES)
What changed from DARS-NIC-380650-K4F6X-v0.14
Text removed is struck through; text added is underlined. Unchanged paragraphs are summarised rather than repeated.
| Field | Was | Became |
|---|---|---|
| Start date | 2022-04-04 | |
| Civil Registrations of Death - Secondary Care Cut: legal basis | Health and Social Care Act 2012 - s261 - 'Other dissemination of information'; National Health Service Act 2006 - s251 - 'Control of patient information'. | |
| HES:Civil Registration (Deaths) bridge: legal basis | Health and Social Care Act 2012 - s261 - 'Other dissemination of information'; National Health Service Act 2006 - s251 - 'Control of patient information'. | |
| Hospital Episode Statistics Admitted Patient Care (HES APC): legal basis | Health and Social Care Act 2012 - s261 - 'Other dissemination of information'; National Health Service Act 2006 - s251 - 'Control of patient information'. | |
| Patient Reported Outcome Measures (Linkable to HES): legal basis | Health and Social Care Act 2012 - s261 - 'Other dissemination of information'; National Health Service Act 2006 - s251 - 'Control of patient information'. |
Objective for processing
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available.*** [56 paragraphs unchanged]
Processing activities
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available. ***
[11 paragraphs unchanged]
(ii) NHS Digital will identify a cohort of patients with a hip
[5 words unchanged]
Oxford will send in the operation codes) from HES APC (1998/99 to
2019/20)
Latest Available)
[2 paragraphs unchanged]
-All HES APC episodes for these patients from 1998/99 to
2019/20
Latest Available
[33 paragraphs unchanged]
Expected output
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available.*** [28 paragraphs unchanged]
Expected measurable benefits
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available. *** [5 paragraphs unchanged]
Benefits reported
Stated in the previous version and removed here.
Yielded Benefits is not a requirement for new applications.
Objective for processing
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available.***
Hip and knee replacement implants are designed to last a long time, but do not last forever. A revision joint replacement is a procedure to replace an implant that is no longer functioning correctly. These procedures are major surgery because performing a joint replacement can be much more complicated the second (or third) time. This may be due to the presence of infection or formation of scar tissue and loss of bone over time. Around 13,000 revision operations are performed each year in the United Kingdom at a cost of up to £200 million.
Whilst many procedures are successful, previous studies have estimated that up to one-in-three patients do not report any benefit from surgery. The reasons for this are not well understood. The University of Oxford study team are aware of only one study (Baker et al, 2012) that has analysed National Joint Registry (NJR) data linked to Patient reported Outcome Measures (PROMs) for revision joint replacement – reporting on knee procedures only in 797 patients. The proposed study (subject of this agreement) will provide new information on the outcomes from revision hip and knee replacement in a much larger cohort and the factors associated to these outcomes. This information can be used to support shared decision making, to allow patients to make a better-informed decision of whether to undergo revision surgery. Since all patients undergoing revision hip or knee replacement will have experienced primary joint replacement, comparison to primary joint replacement is useful for communication of risks and expected benefits from surgery.
The University of Oxford requires Hospital Episode Statistics (HES), PROMs and Civil Registration (mortality) data for the purpose of an investigation to determine the outcomes from revision hip and knee joint replacement. This study will investigate temporal and geographic variation in these outcomes, and the factors associated to these outcomes. The proposed work will be undertaken by individuals from the Big Health Data Group, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, at the University of Oxford. The work requires the HES, PROMS and mortality data controlled by NHS Digital to be linked to National Joint Registry (NJR) data - for which Healthcare Quality Improvement Partnership (HQIP) is the data controller - and would be supplied by HQIP’s data processor, Northgate Information Solutions. All linked NJR and NHS Digital data accessible to the team at the University of Oxford will be pseudonymised. Northgate Information Solutions will have no access to NHS Digital data under this Agreement.
The National Joint Registry is currently responsible for monitoring knee replacements, and commonly collaborates with external groups to investigate outcomes of arthroplasty and relies on GDPR Article 6(1)(e) as the lawful basis to do this. There is public interest from patients undergoing hip and knee arthroplasty to understand the risks and likely benefit of the surgical procedure. This interest has been formalised, for example, the James Lind Alliance Priority Setting Partnership which is made up of patients, carers and clinicians, identified research into revision hip and knee replacement as a key priority. The following key questions generated by this process will be directly addressed in this work:
-What are the most effective ways to organise healthcare and avoid delay to improve the results and patients’ experience of revision knee surgery?
-What factors determine (predict) whether revision knee surgery is likely to work?
-How should one measure the outcomes following revision knee surgery in a way that is meaningful to patients, and is surgery cost effective?
-What are the best forms of surgery to use for revision knee surgery including choice of implant and technique?
The moral and ethical issues include the processing of patient data without consent and the risk of breach of patient confidentiality through transfer and processing of records. These issues have been addressed as follows:
- Research Ethics Committee approval (REC 20/LO/0428)
- CAG Section 251 support (20/CAG/0044)
- Patient and Public Involvement work has been performed at the University of Oxford (with positive feedback) to evaluate patient views on (i) data linkage without consent and (ii) this programme of research.
To minimise risk, University of Oxford has requested pseudonymised records and will also suppress data on small volume groups in dissemination of study results in line with the HES analysis guide.
The data requested includes both the outcomes and predictors of interest. Analysis of these will provide important information on revision hip and knee replacement. The outcomes of interest are patient-reported outcome measures, quality of life measures, mortality, revisions, re-operations and healthcare resource utilisation. The predictors of interest can be classified into patient, surgical, temporal and geographic factors. For example, patient factors include the effects of age, body mass index and pre-existing comorbidities on the outcomes of interest. Surgical factors include the type of procedure and implants used. Temporal and geographic factors include year of surgery, the type of centre (e.g. high volume or low volume caseload) and region.
This study will analyse pseudonymised data from several sources within the NHS that routinely collect information related to revision joint replacement. The University of Oxford will analyse data on patient satisfaction from Patient Reported Outcome Measures; hospital admissions from Hospital Episode Statistics; joint replacements from the National Joint Registry; and mortality from Civil Registration (Deaths). The University of Oxford will analyse this data to describe patient satisfaction and function after revision surgery, medical risks, and the need for further surgery and identify the factors that underpin each of these. The University of Oxford will compare data on revision joint replacement to primary joint replacement.
A DPhil student will form part of the study team. The DPhil student who will collaborate on this work is funded by the Royal College of Surgeons (RCS). The RCS will have no access to the data and no role in its analysis or interpretation. Data from this application will support a chapter on the outcomes of revision knee replacement by the indication for surgery. Other DPhil chapters within this thesis include:
(i) A scoping review of the use of PROMs and their validity for revision knee replacement [submitted for publication];
(ii) Validation of the Oxford Knee Score for revision knee replacement [submitted for publication];
(iii) A systematic review of patient-relevant outcomes following revision knee replacement [in progress].
A description of the data subjects is provided below:
Revision Cohort:
Inclusion-
- Male or Female, aged 18 years or above, AND
- Has undergone revision hip or knee replacement from April 2003 to present, WITH
- Procedure recorded on either HES APC or NJR
Controls:
- Male or Female, aged 18 years or above, AND
- Has undergone primary hip or knee replacement from April 2003 to present, WITH
- Procedure recorded on either HES APC or NJR
This project will address the following specific research questions:
-What are the patient-reported outcomes from revision hip and knee replacement?
-What are the short-term outcomes/complications of revision hip and knee replacement?
-What are the longer-term outcomes from revision hip and knee replacement?
The outcomes of interest have been defined above. For each of these research questions, the proposed work will identify patient, surgeon, institution, temporal and geographic associations to these outcomes.
There is an unmet need to identify the factors which affect whether a patient will benefit from revision surgery and to determine the outcomes from surgery. This proposal will provide evidence to allow patients to fully participate in the decision as to whether to undergo revision surgery. It will create clinical guidelines to support surgeons and will guide improvements in the revision hip and knee replacement pathway.
The datasets requested
-HES APC – This is required to identify primary and revision procedures, and provide data on both outcomes and predictors
-PROMS - This dataset is required to identify patient-reported outcomes and predictors for outcome
-Mortality – This dataset is required to identify mortality associated with revision procedures. This information will be used to communicate risk to patients.
Pseudonymised, patient-level data is required in order to support statistical analyses to identify associations to outcomes.
The University of Oxford has requested data from 1998:
a) To investigate temporal changes in arthroplasty practices. 2003 represents the start of the NJR and data are likely to be relevant to modern arthroplasty practices. A data request from 1998 permits a maximum 5 year look back for participants to allow assessment of pre-existing comorbidity.
b) To provide a sufficiently large dataset to control for a large number of variables as the indications for, and the patients undergoing revision joint replacement are heterogenous. The University of Oxford expects to analyse around 200,000 joint replacement procedures.
This study will analyse both national practices and geographic variations in practice across England.
There are no alternative, less intrusive ways of achieving the purpose. The University of Oxford study team has considered analysis of the candidate datasets alone. However, neither provide sufficiently granular information. For example, use of the NJR dataset alone is limited by:
(i) Poor compliance prior to 2008 leading to incomplete case ascertainment
(ii) Limited information to provide case mix adjustment (only age, sex, BMI and ASA grade)
(iii) Incomplete data on re-revisions (due to changing requirements for NJR reporting) and re-operations (not captured)
(iv) No data on medical complications, or hospital admission factors.
The addition of HES data overcomes these limitations and is expected to contribute additional cases, allow better case-mix adjustment and better capture complications and long-term outcomes. HES data cannot be analysed alone as it provides insufficient granularity on procedural coding for this study (for example, type of revision procedure, implants used, surgeon factors). This study is interested to report national outcomes and analysis of local data would not fulfil this objective. To minimise the required data the proposed work will:
(i) Restrict data to records linked to patients from the NJR cohort, OR
(ii) Patients who match with an OPCS code for a primary or revision hip or knee replacement in the HES APC dataset from 2003 to 2020, OR
(iii) Patients with a hip or knee replacement on the PROMs dataset
The ‘OR’ is important above in order to capture cases not submitted to the National Joint Registry (which has recently changed its definition of revision joint replacement). The proposed work requires a five-year look back from the index joint replacement procedure (primary or revision) on the NJR or HES APC to allow for calculation of Charlson Comorbidity Index (a measure of a patient’s pre-existing health problems, previously used to predict patient’s risk of dying whilst admitted to hospital, and as a predictor of the outcome following joint replacement). All HES, PROMs, and Civil Registration (Deaths) episodes after the index joint replacement procedure are of interest as the proposed work is concerned with both short- and long-term outcomes following surgery.
From the PROMS dataset, the proposed work will exclude records related to non-joint replacement procedures (varicose veins, hernia repairs) as these are not relevant. However, the remaining records and fields are relevant to provide both patient-reported outcomes and complications.
The proposed work would be undertaken by individuals from the Big Health Data Group, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, at the University of Oxford. This work requires HES, PROMS and mortality data controlled by NHS Digital to be linked to National Joint Registry (NJR) data - for which HQIP is the data controller - and would be supplied by HQIP’s data processor, Northgate Information Solutions. All data accessible to the team at the University of Oxford will be pseudonymised. Northgate Information Solutions will have no access to NHS Digital data under this Agreement. The NJR Research Steering Committee and the Healthcare Quality Improvement Partnership Data Access Request Group (HQIP DARG) have both approved this application (NJR REF: RSC 2017/26).
Expected output
*** January 2022: v1 of NIC-380650 is an amendment to include two HES APC data fields that were initially omitted from the request and to add 2020/21 and latest available to HES APC as these are now available.***
The specific outputs from the proposed work can be classified as:
1. Peer reviewed journal publications. This will include original articles on patient-reported outcomes, short term complications and longer term outcomes from revision hip and knee replacements. These publications will be Open Access. A first publication is target at 9 months from data receipt, with further publications at 6 monthly intervals.
2. Conference presentations: The proposed work will be presented at national and international conferences. This is to engage a broad spectrum of surgeons and allied health professionals who practice in or around revision joint replacement surgery across the UK. The British Association of Surgeons of the Knee (BASK) and British Orthopaedic Association (BOA) Annual Meetings in 2021 are targets for presentation of the proposed work.
3. Clinical practice guidelines. The University of Oxford study team work closely with BASK and the BOA and have been involved in recent work to produce British Orthopaedic Association Standards (BOASts) which are guidelines on the management of orthopaedic conditions. The evidence generated from the proposed work will be used to update the BOASTs for revision joint replacement. The target date for this is 2023.
4. Social media engagement with patients, surgeons, researchers and allied health professionals. The NDORMs Twitter account (@ndorms) will be used to announce study progress and results. This is intended to engage patients, surgeons and researchers with research outputs as they are produced.
5. Public reports: A project summary will be provided on the NDORMs study webpage. The proposed work will also produce a summary for the National Joint Registry Annual Report. This first summary is intended for the NJR 19th Annual report in 2022.
6. DPhil thesis. This is intended to be published Open Access in 2023 to provide information on outcomes following revision knee replacement. The DPhil student is funded by the Royal College of Surgeons (RCS). The RCS will have no access to the data and no role in its analysis or interpretation.
7. Patients engagement work: The University of Oxford has already started to involve patients and the public with this proposal and will continue this over the duration of the proposal. The Patient and Public Involvement Strategy for this proposal is as follows:
(i) Establishing key priorities for research on revision joint replacement.
See previous references to James Lind Alliance Priority Setting Partnership work.
(ii) Establishing patient views on data linkage without consent
This has been tested in 4 patients known to the research team (mix of men, women, different ages, from various parts of the country who have had a known problem with an implant after surgery). Patients were chosen as a convenience sample by the Nuffield Orthopaedic Centre, Oxford. 4/4 patients agreed that it would not be practical to contact all patients to obtain consent due to the size of the population. The feedback from all had a common theme: the potential benefits from new information on revision knee replacement meant that it was important for this research to be performed. They were satisfied that opt-out mechanisms were in place should patients wish to do so.
(iii) Establishing patient views on the programme of revision knee replacement research proposed
Telephone interviews have been performed with four patients to describe the proposed research programme. They provided very positive feedback. Some quotes were:
-“This will provide very useful information”
-“I think it can help others in the future, and it seems like a very good idea”
-“I have been through several operations on my knee and there isn’t much information out there for patients like me.”
-“I actually had very good information from Oxford when undergoing my revision knee replacement, and I really wish that information on revision knee replacement was rather better known around the country.”
(iv) Extended PPI work
The University of Oxford is recruiting a PPI group of 8-12 patients who are awaiting or have undergone revision knee replacement. The University of Oxford will explore with this group:
-What factors are important to patients in the decision to undergo revision knee replacement?
-How should outcomes following revision knee replacement be evaluated in a way that is meaningful to patients?
This group is currently being recruited.
(v) Revision arthroplasty study website
This is being set-up. Lay summaries of research will be available on this website.
(vi) Open days
These were held regularly, but are currently paused due to Covid-19, but will be reinstated in-person or virtually within the first year of the project.
All outputs will contain only data that is aggregated with small numbers suppressed in line with the HES Analysis Guide.
DARS-NIC-380650-K4F6X-v0.14 12 May 2021 to 5 May 2024
- Title
- Revision Hip and Knee Replacements: Evaluation of Clinical, Psychological and Surgical Outcomes
- Commercial
- No
- Sublicensing
- No
- Datasets
- 4
- Files released
- 0
Datasets: Civil Registrations of Death - Secondary Care Cut; HES:Civil Registration (Deaths) bridge; Hospital Episode Statistics Admitted Patient Care (HES APC); Patient Reported Outcome Measures (Linkable to HES)
Objective for processing
Hip and knee replacement implants are designed to last a long time, but do not last forever. A revision joint replacement is a procedure to replace an implant that is no longer functioning correctly. These procedures are major surgery because performing a joint replacement can be much more complicated the second (or third) time. This may be due to the presence of infection or formation of scar tissue and loss of bone over time. Around 13,000 revision operations are performed each year in the United Kingdom at a cost of up to £200 million.
Whilst many procedures are successful, previous studies have estimated that up to one-in-three patients do not report any benefit from surgery. The reasons for this are not well understood. The University of Oxford study team are aware of only one study (Baker et al, 2012) that has analysed National Joint Registry (NJR) data linked to Patient reported Outcome Measures (PROMs) for revision joint replacement – reporting on knee procedures only in 797 patients. The proposed study (subject of this agreement) will provide new information on the outcomes from revision hip and knee replacement in a much larger cohort and the factors associated to these outcomes. This information can be used to support shared decision making, to allow patients to make a better-informed decision of whether to undergo revision surgery. Since all patients undergoing revision hip or knee replacement will have experienced primary joint replacement, comparison to primary joint replacement is useful for communication of risks and expected benefits from surgery.
The University of Oxford requires Hospital Episode Statistics (HES), PROMs and Civil Registration (mortality) data for the purpose of an investigation to determine the outcomes from revision hip and knee joint replacement. This study will investigate temporal and geographic variation in these outcomes, and the factors associated to these outcomes. The proposed work will be undertaken by individuals from the Big Health Data Group, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, at the University of Oxford. The work requires the HES, PROMS and mortality data controlled by NHS Digital to be linked to National Joint Registry (NJR) data - for which Healthcare Quality Improvement Partnership (HQIP) is the data controller - and would be supplied by HQIP’s data processor, Northgate Information Solutions. All linked NJR and NHS Digital data accessible to the team at the University of Oxford will be pseudonymised. Northgate Information Solutions will have no access to NHS Digital data under this Agreement.
The National Joint Registry is currently responsible for monitoring knee replacements, and commonly collaborates with external groups to investigate outcomes of arthroplasty and relies on GDPR Article 6(1)(e) as the lawful basis to do this. There is public interest from patients undergoing hip and knee arthroplasty to understand the risks and likely benefit of the surgical procedure. This interest has been formalised, for example, the James Lind Alliance Priority Setting Partnership which is made up of patients, carers and clinicians, identified research into revision hip and knee replacement as a key priority. The following key questions generated by this process will be directly addressed in this work:
-What are the most effective ways to organise healthcare and avoid delay to improve the results and patients’ experience of revision knee surgery?
-What factors determine (predict) whether revision knee surgery is likely to work?
-How should one measure the outcomes following revision knee surgery in a way that is meaningful to patients, and is surgery cost effective?
-What are the best forms of surgery to use for revision knee surgery including choice of implant and technique?
The moral and ethical issues include the processing of patient data without consent and the risk of breach of patient confidentiality through transfer and processing of records. These issues have been addressed as follows:
- Research Ethics Committee approval (REC 20/LO/0428)
- CAG Section 251 support (20/CAG/0044)
- Patient and Public Involvement work has been performed at the University of Oxford (with positive feedback) to evaluate patient views on (i) data linkage without consent and (ii) this programme of research.
To minimise risk, University of Oxford has requested pseudonymised records and will also suppress data on small volume groups in dissemination of study results in line with the HES analysis guide.
The data requested includes both the outcomes and predictors of interest. Analysis of these will provide important information on revision hip and knee replacement. The outcomes of interest are patient-reported outcome measures, quality of life measures, mortality, revisions, re-operations and healthcare resource utilisation. The predictors of interest can be classified into patient, surgical, temporal and geographic factors. For example, patient factors include the effects of age, body mass index and pre-existing comorbidities on the outcomes of interest. Surgical factors include the type of procedure and implants used. Temporal and geographic factors include year of surgery, the type of centre (e.g. high volume or low volume caseload) and region.
This study will analyse pseudonymised data from several sources within the NHS that routinely collect information related to revision joint replacement. The University of Oxford will analyse data on patient satisfaction from Patient Reported Outcome Measures; hospital admissions from Hospital Episode Statistics; joint replacements from the National Joint Registry; and mortality from Civil Registration (Deaths). The University of Oxford will analyse this data to describe patient satisfaction and function after revision surgery, medical risks, and the need for further surgery and identify the factors that underpin each of these. The University of Oxford will compare data on revision joint replacement to primary joint replacement.
A DPhil student will form part of the study team. The DPhil student who will collaborate on this work is funded by the Royal College of Surgeons (RCS). The RCS will have no access to the data and no role in its analysis or interpretation. Data from this application will support a chapter on the outcomes of revision knee replacement by the indication for surgery. Other DPhil chapters within this thesis include:
(i) A scoping review of the use of PROMs and their validity for revision knee replacement [submitted for publication];
(ii) Validation of the Oxford Knee Score for revision knee replacement [submitted for publication];
(iii) A systematic review of patient-relevant outcomes following revision knee replacement [in progress].
A description of the data subjects is provided below:
Revision Cohort:
Inclusion-
- Male or Female, aged 18 years or above, AND
- Has undergone revision hip or knee replacement from April 2003 to present, WITH
- Procedure recorded on either HES APC or NJR
Controls:
- Male or Female, aged 18 years or above, AND
- Has undergone primary hip or knee replacement from April 2003 to present, WITH
- Procedure recorded on either HES APC or NJR
This project will address the following specific research questions:
-What are the patient-reported outcomes from revision hip and knee replacement?
-What are the short-term outcomes/complications of revision hip and knee replacement?
-What are the longer-term outcomes from revision hip and knee replacement?
The outcomes of interest have been defined above. For each of these research questions, the proposed work will identify patient, surgeon, institution, temporal and geographic associations to these outcomes.
There is an unmet need to identify the factors which affect whether a patient will benefit from revision surgery and to determine the outcomes from surgery. This proposal will provide evidence to allow patients to fully participate in the decision as to whether to undergo revision surgery. It will create clinical guidelines to support surgeons and will guide improvements in the revision hip and knee replacement pathway.
The datasets requested
-HES APC – This is required to identify primary and revision procedures, and provide data on both outcomes and predictors
-PROMS - This dataset is required to identify patient-reported outcomes and predictors for outcome
-Mortality – This dataset is required to identify mortality associated with revision procedures. This information will be used to communicate risk to patients.
Pseudonymised, patient-level data is required in order to support statistical analyses to identify associations to outcomes.
The University of Oxford has requested data from 1998:
a) To investigate temporal changes in arthroplasty practices. 2003 represents the start of the NJR and data are likely to be relevant to modern arthroplasty practices. A data request from 1998 permits a maximum 5 year look back for participants to allow assessment of pre-existing comorbidity.
b) To provide a sufficiently large dataset to control for a large number of variables as the indications for, and the patients undergoing revision joint replacement are heterogenous. The University of Oxford expects to analyse around 200,000 joint replacement procedures.
This study will analyse both national practices and geographic variations in practice across England.
There are no alternative, less intrusive ways of achieving the purpose. The University of Oxford study team has considered analysis of the candidate datasets alone. However, neither provide sufficiently granular information. For example, use of the NJR dataset alone is limited by:
(i) Poor compliance prior to 2008 leading to incomplete case ascertainment
(ii) Limited information to provide case mix adjustment (only age, sex, BMI and ASA grade)
(iii) Incomplete data on re-revisions (due to changing requirements for NJR reporting) and re-operations (not captured)
(iv) No data on medical complications, or hospital admission factors.
The addition of HES data overcomes these limitations and is expected to contribute additional cases, allow better case-mix adjustment and better capture complications and long-term outcomes. HES data cannot be analysed alone as it provides insufficient granularity on procedural coding for this study (for example, type of revision procedure, implants used, surgeon factors). This study is interested to report national outcomes and analysis of local data would not fulfil this objective. To minimise the required data the proposed work will:
(i) Restrict data to records linked to patients from the NJR cohort, OR
(ii) Patients who match with an OPCS code for a primary or revision hip or knee replacement in the HES APC dataset from 2003 to 2020, OR
(iii) Patients with a hip or knee replacement on the PROMs dataset
The ‘OR’ is important above in order to capture cases not submitted to the National Joint Registry (which has recently changed its definition of revision joint replacement). The proposed work requires a five-year look back from the index joint replacement procedure (primary or revision) on the NJR or HES APC to allow for calculation of Charlson Comorbidity Index (a measure of a patient’s pre-existing health problems, previously used to predict patient’s risk of dying whilst admitted to hospital, and as a predictor of the outcome following joint replacement). All HES, PROMs, and Civil Registration (Deaths) episodes after the index joint replacement procedure are of interest as the proposed work is concerned with both short- and long-term outcomes following surgery.
From the PROMS dataset, the proposed work will exclude records related to non-joint replacement procedures (varicose veins, hernia repairs) as these are not relevant. However, the remaining records and fields are relevant to provide both patient-reported outcomes and complications.
The proposed work would be undertaken by individuals from the Big Health Data Group, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, at the University of Oxford. This work requires HES, PROMS and mortality data controlled by NHS Digital to be linked to National Joint Registry (NJR) data - for which HQIP is the data controller - and would be supplied by HQIP’s data processor, Northgate Information Solutions. All data accessible to the team at the University of Oxford will be pseudonymised. Northgate Information Solutions will have no access to NHS Digital data under this Agreement. The NJR Research Steering Committee and the Healthcare Quality Improvement Partnership Data Access Request Group (HQIP DARG) have both approved this application (NJR REF: RSC 2017/26).
Expected output
The specific outputs from the proposed work can be classified as:
1. Peer reviewed journal publications. This will include original articles on patient-reported outcomes, short term complications and longer term outcomes from revision hip and knee replacements. These publications will be Open Access. A first publication is target at 9 months from data receipt, with further publications at 6 monthly intervals.
2. Conference presentations: The proposed work will be presented at national and international conferences. This is to engage a broad spectrum of surgeons and allied health professionals who practice in or around revision joint replacement surgery across the UK. The British Association of Surgeons of the Knee (BASK) and British Orthopaedic Association (BOA) Annual Meetings in 2021 are targets for presentation of the proposed work.
3. Clinical practice guidelines. The University of Oxford study team work closely with BASK and the BOA and have been involved in recent work to produce British Orthopaedic Association Standards (BOASts) which are guidelines on the management of orthopaedic conditions. The evidence generated from the proposed work will be used to update the BOASTs for revision joint replacement. The target date for this is 2023.
4. Social media engagement with patients, surgeons, researchers and allied health professionals. The NDORMs Twitter account (@ndorms) will be used to announce study progress and results. This is intended to engage patients, surgeons and researchers with research outputs as they are produced.
5. Public reports: A project summary will be provided on the NDORMs study webpage. The proposed work will also produce a summary for the National Joint Registry Annual Report. This first summary is intended for the NJR 19th Annual report in 2022.
6. DPhil thesis. This is intended to be published Open Access in 2023 to provide information on outcomes following revision knee replacement. The DPhil student is funded by the Royal College of Surgeons (RCS). The RCS will have no access to the data and no role in its analysis or interpretation.
7. Patients engagement work: The University of Oxford has already started to involve patients and the public with this proposal and will continue this over the duration of the proposal. The Patient and Public Involvement Strategy for this proposal is as follows:
(i) Establishing key priorities for research on revision joint replacement.
See previous references to James Lind Alliance Priority Setting Partnership work.
(ii) Establishing patient views on data linkage without consent
This has been tested in 4 patients known to the research team (mix of men, women, different ages, from various parts of the country who have had a known problem with an implant after surgery). Patients were chosen as a convenience sample by the Nuffield Orthopaedic Centre, Oxford. 4/4 patients agreed that it would not be practical to contact all patients to obtain consent due to the size of the population. The feedback from all had a common theme: the potential benefits from new information on revision knee replacement meant that it was important for this research to be performed. They were satisfied that opt-out mechanisms were in place should patients wish to do so.
(iii) Establishing patient views on the programme of revision knee replacement research proposed
Telephone interviews have been performed with four patients to describe the proposed research programme. They provided very positive feedback. Some quotes were:
-“This will provide very useful information”
-“I think it can help others in the future, and it seems like a very good idea”
-“I have been through several operations on my knee and there isn’t much information out there for patients like me.”
-“I actually had very good information from Oxford when undergoing my revision knee replacement, and I really wish that information on revision knee replacement was rather better known around the country.”
(iv) Extended PPI work
The University of Oxford is recruiting a PPI group of 8-12 patients who are awaiting or have undergone revision knee replacement. The University of Oxford will explore with this group:
-What factors are important to patients in the decision to undergo revision knee replacement?
-How should outcomes following revision knee replacement be evaluated in a way that is meaningful to patients?
This group is currently being recruited.
(v) Revision arthroplasty study website
This is being set-up. Lay summaries of research will be available on this website.
(vi) Open days
These were held regularly, but are currently paused due to Covid-19, but will be reinstated in-person or virtually within the first year of the project.
All outputs will contain only data that is aggregated with small numbers suppressed in line with the HES Analysis Guide.
Benefits reported
Yielded Benefits is not a requirement for new applications.
Register history
When this agreement appeared in, or was edited in, each monthly edition of the register. Built by comparing every edition this site holds.
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September 2021 —
first listed. 1 version: DARS-NIC-380650-K4F6X-v0.14
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April 2022
1 version added: DARS-NIC-380650-K4F6X-v1.3
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December 2022
Register-wide edit DARS-NIC-380650-K4F6X-v0.14 — Datasets: legal basis: “
s261(1) and” taken out. Made to 639 agreements in this edition, so it is reported once, on the changes page, and not counted as an amendment of this agreement. -
June 2024
1 version added: DARS-NIC-380650-K4F6X-v2.5
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May 2025
1 version added: DARS-NIC-380650-K4F6X-v3.3
Cite this page
NHS England (2026) Data Uses Register, September 2026 edition, agreement DARS-NIC-380650-K4F6X, “Revision Hip and Knee Replacements: Evaluation of Clinical, Psychological and Surgical Outcomes”. Read via NHS Data Access Explorer (unofficial), https://healthdatauses.uk/agreements/dars-nic-380650-k4f6x/ (accessed [date]).
This address stays the same, but the page is rebuilt with each monthly edition, so the citation names the edition it shows. Every edition's data is kept in the facts store.
Source: datausesregister_september2026.xlsx, September 2026 edition of the NHS England Data Uses Register. Search that workbook for DARS-NIC-380650-K4F6X to see the original rows.