National Joint Registry for England and Wales 4th Annual Report

Transcription

1 National Joint Registry ISSN National Joint Registry for England and Wales 4th Annual Report

2 Prepared by The NJR Centre, Hemel Hempstead Peter Drury Julia Morrison Claire Newell Dr Martin Pickford Martin Royall Mike Swanson Lynn May, M&M Communications Royal College of Surgeons Clinical Effectiveness Unit Jan van der Meulen Nokuthaba Sibanda The Department of Health The NJR Steering Committee This document is available in PDF format for download on the NJR website.

3 Contents Chairman s Introduction 07 Vice-Chairman s Introduction 08 Executive Summary 09 Part 1 1. Introduction Annual Report The National Joint Registry Progress Challenges Progress Key Figures Developments NJR Stakeholders, Support and Governance Information, Communication and Monitoring Finance Income and Expenditure Changes to the Levy Taking The NJR Forward Improving Data Quality and Completeness Service Development The Future NJR Steering Committee 29 Appendices Appendix 1 NJR Steering Committee 2006/07 31 Appendix 2 NJR Steering Committee Terms of Reference 34 Appendix 3 Regional Clinical Coordinators 35 Appendix 4 Regional Clinical Coordinators Network Terms of Reference 36 Appendix 5 NJR Services to Stakeholders 37 Appendix 6 NJR Units Not Returning Data in 2006/07 38 Appendix 7 Supporting Data for Figures 39 Appendix 8 Locations of Audit and Training Meetings 41 Tables Table 1 Provider: distribution of operations by type (hip or knee) and provider organisation, NJR records, 2004/05 to 2006/07 Figures Figure 1 NJR Compliance: , based on levies from implant sales Figure 2 NJR Consent: quarterly analysis of total records received and those with patient consent, 2003/ /07 Figure 3 NJR Linkability: analysis of total records received and those for which NHS numbers have been traced, 2003/ /07 Figure 4 Total: hip and knee joint replacement operations entered on the NJR, 2003/04 to 2006/07, recorded by country in which the operation took place Figure 5 Type: hip and knee joint replacement operations entered on the NJR, 2003/04 to 2006/07, recorded by type of operation Figure 6 Provider: distribution of hip and knee replacement operations by provider organisation, NJR records, for the three years 2004/05 to 2006/07 4th Annual Report 03

4 Part 2 1. Introduction Compliance and Linkage to the Hospital Episode Statistics Database Compliance for Procedures Undertaken in Linkage of NJR Procedures to HES Episodes Overview of Hip and Knee Replacement Procedures, Hospitals and Treatment Centres Participating in the NJR Hip Replacement Procedures Knee Replacement Procedures Hip Replacement Procedures Hip Replacement Procedures, Outcomes Following Primary Hip Replacement, Knee Replacement Procedures Knee Replacement Procedures, Outcomes Following Primary Knee Replacements, Prostheses Used in Hip and Knee Replacement Procedures Prostheses Used in Hip Procedures Prostheses Used in Knee Procedures Cement Use Bone Substitute Use 111 Appendices Appendix 1 Assessment Criteria for Total Hip Prostheses Utilised by the Orthopaedic Data Evaluation Panel (ODEP) 128 Tables Table 2.1 Hip or knee joint replacement procedures carried out in England between 1 April 2003 and 30 September 2006 that were linked to a HES episode, by provider type Table 2.2 Comparison of patient, procedure and provider type for HES-linked and non HES-linked hip replacement procedures, 1 April 2003 to 30 September 2006 Table 2.3 Comparison of patient, procedure and provider type for HES-linked and non HES-linked knee replacement procedures, 1 April 2003 to 30 September 2006 Table 3.1 Total number of hospitals and Treatment Centres in England and Wales able to participate in the NJR and proportion actually participating in 2006 Table 3.2 Number of participating hospitals according to number of procedures entered over the 2006 data collection period Table 3.3 Patient characteristics and procedure details according to type of provider for hip procedures in 2006 Table 3.4 Patient characteristics and procedure details according to type of provider for knee procedures in 2006 Table 4.1 Patient characteristics for primary hip replacement procedures in 2006, according to type of procedure Table 4.2 Age and gender for primary hip replacements in 2006 Table 4.3 Characteristics of surgical practice for primary hip replacement procedures in 2006, according to type of procedure Table 4.4 Thromboprophylaxis regime for primary hip replacement patients prescribed at time of operation, according to procedure Table 4.5 Reported untoward intra-operative events for primary hip replacement patients in 2006 according to procedure type Table 4.6 Patient characteristics for hip revision procedures in 2006, according to procedure type Table 4.7 Indication for surgery for hip revision procedures in 2004 to National Joint Registry

5 Table 4.8 Components removed during hip revision procedures in 2006 Table 4.9 Components used during single stage hip revision procedures in 2006 Table 4.10 Types of hip re-operation other than revisions in 2006 Table 4.11 Characteristics of patients undergoing hip re-operations other than revision Table 4.12 Revision at 1 year for primary hip replacement procedures undertaken between 1 April 2003 and 30 September 2006 that were linked to a HES episode Table 4.13 Causes of failure for primary hip replacement implants undertaken between 1 April 2003 and 30 September 2006 that were linked to a HES episode and had a revision also linked to a HES episode Table 4.14 Mortality rates and age-and-gender-standardised mortality ratios at 1 year following primary hip replacement for procedures linked to a HES `episode, Table 4.15 Mortality at 1 year for primary hip replacement procedures undertaken between 1 April 2003 and 30 June 2006 that were linked to a HES episode Table 4.16 Length of hospital stay following admission for a primary hip replacement for procedures linked to a HES episode Table 4.17 Length of hospital stay following admission for a primary hip procedure according to age and gender for procedures linked to a HES episode, Table 5.1 Patient characteristics for primary knee replacement procedures in 2006, according to type of procedure Table 5.2 Age and gender for primary knee replacements in 2006 Table 5.3 Characteristics of surgical practice for primary knee replacement procedures in 2006, according to type of procedure Table 5.4 Thromboprophylaxis regime for primary knee replacement patients prescribed at time of operation, according to procedure Table 5.5 Reported untoward intra-operative events for primary knee replacement patients in 2006 according to procedure type Table 5.6 Patient characteristics for knee revision procedures in 2006, according to procedure type Table 5.7 Combinations of implants removed during Single and 2-Stage Knee Revision procedures in 2006 Table 5.8 Types of knee re-operations entered into the NJR database Table 5.9 Characteristics of patients undergoing knee re-operations other than revision Table 5.10 Revision at 1 year for primary knee replacement procedures undertaken between 1 April 2003 and 30 September 2006 that were linked to a HES episode Table 5.11 Causes of failure for primary knee replacement implants undertaken between 1 April 2003 and 30 September 2006 that were linked to a HES episode and had a revision also linked to a HES episode Table 5.12 Mortality rates and age-and-gender-standardised mortality ratios at 1 year following primary knee replacement for procedures linked to a HES episode, Table 5.13 Mortality at 1 year for primary knee replacement procedures undertaken between 1 April 2003 and 30 June 2006 that were linked to a HES episode Table 5.14 Length of hospital stay (days) following admission for a primary knee replacement for procedures linked to a HES episode, Table 6.1 Frequency of material chosen for femoral heads in procedures performed in 2006 Table 6.2 Frequency of femoral head sizes for procedures performed in 2006 Table 6.3 Tibial insert type 2006 Table 6.4 Type of cement used in hip and knee replacement procedure cement entered into the NJR in 2006 Table 6.5 Cemented cup brands entered during 2006 for hip replacements Table 6.6 Cementless cup brands entered during 2006 for hip replacements Table 6.7 Cemented stem brands entered during 2006 for hip replacements Table 6.8 Cementless stem brands entered during 2006 for hip replacements Table 6.9 Brands of resurfacing heads entered into the NJR in 2006 Table 6.10 Procedures using a resurfacing cup with a conventional stem in 2006 Table 6.11 Top 20 Cup - Stem combinations recorded in the NJR in 2006 Table 6.12 Total Condylar knee brands entered into the NJR in 2006 for total knee replacements and hybrid and revision procedures 4th Annual Report 05

6 Table 6.13 Unicondylar knee brands entered into the NJR in 2006 for unicondylar knee procedures Table 6.14 Patello-femoral joint brands entered into the NJR in 2006 for patello-femoral joint replacement procedures Table 6.15 Fixed and rotating hinged knee brands 2006 Table 6.16 Brands of antibiotic bone cement entered into the NJR in 2006 Table 6.17 Brands of non-antibiotic bone cement entered into the NJR in 2006 Table 6.18 Brands of synthetic bone substitute entered into the NJR in 2006 Figures Figure 2.1 Flow chart illustrating linkage of the NJR with HES Figure 3.1 Number of participating hospitals by number of procedures, Figure 3.2 Primary hip procedures by provider type Figure 3.3 Primary knee procedures by provider type Figure 4.1 Type of primary hip replacement procedure undertaken between 2004 and 2006 Figure 4.2 Age and gender for primary hip replacement patients in 2006 Figure 4.3 Revision rate estimates for HES-linked primary hip replacement procedures, Figure 4.4 Revision rate estimates by age for HES-linked primary hip replacement procedures, Figure 4.5 Revision rate estimates for male and female patients with HES-linked primary hip replacement procedures Figure 4.6 Revision rate estimates for the five most commonly used hip cemented stem brands, Figure 4.7 Revision rate estimates for the three most commonly used hip cementless stem brands, Figure 4.8 Revision rate estimates for the five most commonly used hip cemented cup brands, Figure 4.9 Revision rate estimates for the three most commonly used hip cementless cup brands, Figure 4.10 Revision rate estimates for the most commonly used brand of hip resurfacing prostheses, Figure 4.11 Mortality for patients with and those without any thromboprophylaxis prescribed at the time of primary hip replacement, Figure 5.1 Revision rate estimates for HES-linked primary knee replacement procedures, Figure 5.2 Revision rate estimates by age for HES-linked primary knee replacement procedures, Figure 5.3 Survival to revision and revision rates for male and female patients with HES-linked primary knee replacement procedures, Figure 5.4 Revision rate estimates for the five most commonly used brands of total condylar knee prostheses, Figure 5.5 Revision rate estimates for the most commonly used brand of unicondylar knee prostheses, Figure 5.6 Revision rates comparing use and non-use of minimally invasive surgery in unicondylar knee procedures, Figure 5.7 Mortality for patients with and those without any thromboprophylaxis prescribed at the time of primary knee replacement, Glossary National Joint Registry

7 Chairman s Introduction Bill Darling C.B.E. D.L. F.R.Pharm.S. It is my pleasure, as Chairman of the National Joint Registry Steering Committee, to introduce our 4th Annual Report. It covers the period from April 2006 to March 2007 with a report on the analysis of data on hip and knee joint replacement operations held on the National Joint Registry in Part 2. I believe this Annual Report will prove to be of greater value to all stakeholders than its three predecessors. As the NJR data base continues to expand the quality, type and value of analysis now available from the NJR has increased significantly. We have made solid progress in a number of areas. In particular NJR Reports Online went live in October 2006 tailored to the specific needs of surgeons and hospital data managers providing access to data in the form of pre-built reports with reports for hospital management planned for the near future. During the year the NJR Information Bureau responded to a large number of requests for information, providing accessibility to data whilst at all times protecting patient and clinician confidentiality. Work on improving patient consent and compliance continues with our targets for June 2008 remaining at 90% and 95% respectively. The number of records now in the registry is close to 450,000. We have seen an increase in the level of patient consent and work is underway to help units produce forms which will allow consent to be obtained at the same time as permission to operate. The key issue of Linkability has been moved to the top of the agenda. Work is ongoing to link the NJR data to that held in the Hospital Episode Statistics (HES) and the Patient Episode Database for Wales (PEDW) which will facilitate a more detailed analysis of the data, in particular relating to revisions and outcomes. This is demonstrated in Part 2 of the Report which looks at NJR and HES linked data, increasing the ability to link revision operations to primary hip and knee joint replacement operations for patients on the NJR database. This will significantly assist survivorship analysis and will be a priority for the year 2007/08. During the year a number of hospitals began to use the NJR data for clinical audit and started to review practice in their hospital in comparison with practice nationally and in doing so seeking to improve the patient care they provide. A development which I welcome and which I hope others will adopt. Once again I record my thanks to Professor Paul Gregg who has given me great support during this year. I would also like to thank the members of the Steering Committee for their commitment and hard work to move the database forward. A key component of this progress has been the work of the Regional Clinical Coordinators who have continued to show great enthusiasm for the project. My thanks also go to the NJR Regional Coordinators; I know that their practical advice, support and guidance to orthopaedic units and other stakeholders has been much appreciated. The input of the Department of Health has been significant and in particular I would like to thank Ramila Mistry and Kate Wortham for all their help and support. Finally I record my thanks to Northgate Information Solutions whose technical expertise has enabled us to make so much progress this year and positioned us to make very real advances during Bill Darling Chairman, NJR Steering Committee 4th Annual Report 07

8 Vice-Chairman s Introduction As Vice-Chairman of the National Joint Registry Steering Committee, I am pleased to introduce Part 2 of the 4th Annual Report. Management of the National Joint Registry was awarded to a new Contractor, Northgate Information Solutions, from the 1 April Despite this significant change, we have made solid progress in a number of areas, as indicated in the Chairman s Introduction to the 4th Annual Report. Compliance and patient consent continue to improve and I am hopeful that by June 2008 our targets of 95% and 90% respectively will be achieved. A major new development has been the work to link consented NJR records to those held in Hospital Episode Statistics (HES). This should improve, dramatically, the ability to link primary procedures with subsequent revisions and, in the future, provide the opportunity of measuring other outcomes following total joint replacement surgery. Already, using this methodology, survivorship analyses for various types of total joint replacement procedures and brands of prostheses have been produced and are published, for the first time, in this Report. In particular, survivorship analysis for a significant number of hip resurfacing procedures has been performed and the results compared with more conventional hip replacement procedures. Data on unicondylar knee prostheses, mortality and its relation to thromboprophylaxis and length of stay are also presented. I believe our surgeons should be justly proud of the results which are published in this Section, particularly those relating to mortality and survivorship. I know that some believe that progress has been slower than wished for, but it is a credit to the progress that has been made, that the size of our National Joint Registry now covers almost 400 orthopaedic units, and is larger than other National Registries, for example the Swedish and Australian Registries. I wish to add my sincere thanks to those of Bill Darling, Chairman of the National Joint Registry Steering Committee, to all those who have contributed to the ongoing development of the National Joint Registry. In particular, I wish to thank Bill for all his hard work both within and outside the Committee and, of course, our surgeons for entering their data and hope that they will continue to do so. Finally, we do wish to encourage the use of NJR data for research and audit purposes. Potentially, we now have an extremely large and important database. Anyone wishing to pursue this possibility should write to the National Joint Registry Centre, following which they will be advised of the appropriate procedure. Paul Gregg Vice-Chairman, NJR Steering Committee 08 National Joint Registry

9 Executive Summary The National Joint Registry 4th Annual Report is the formal public report of the National Joint Registry for the period 1 April 2006 to 31 March In addition it contains an analysis of the data held on the Registry. The National Joint Registry (NJR) was established to improve care for patients who require hip and knee joint replacement implants and surgery. It does this by collecting data that can be used to measure the long-term effectiveness of implants used in hip and knee joint replacement surgery and information about the surgical procedures involved. The work programme of the NJR Centre in England and Wales is set and overseen by the NJR Steering Committee, working with the Department of Health as an advisory non-departmental public body. Part 1 Part 1 of this document reports on the performance and developments of the Registry during the financial year 2006/07. It provides an account of the work, composition and funding of the NJR Steering Committee and indicates key areas for future development. Key achievements and developments during the year 2006/07 included: recording 131,378 hip and knee joint replacement operations, which represented 81% 1 of such operations undertaken in NHS and independent healthcare units in England and Wales and brought the total recorded on the Registry to 433,319 by 31 March 2007 publishing a detailed analysis of data collected by the Registry increasing the number of records with patient consent to personal information being included on the Registry, from 78% in the final quarter of 2005/06 to 83% by end of 2006/07 increasing the number of records with both patient consent and the patient s NHS number, from 58% (as shown in NJR 3rd Annual Report) to 69%. Data capture has been improved by: increasing direct, on-site support for individual hospitals and treatment centres to help them set up or improve processes for submitting information introducing close monitoring of all units to identify those which may require support in improving compliance with NJR requirements gaining retrospective exemption from the Health and Social Care Act 2001, Section 60, which restricted use of the personal details of patients for whom a response of don t know had been allocated in the records patients being asked for consent to provide their personal details to the NJR at the same time as giving their consent to undergo surgery. Information held on the Registry has been made more accessible by: launching NJR ReportsOnline for surgeons and hospital data managers, which provides information about operations, case mix and implant usage improving NJR StatsOnline publishing the NJR Annual Report 2005/06 and 3rd Annual Clinical Report reporting on NJR data and services in its newsletter Joint Approach producing a starter pack of information for new unit staff. Additional developments include: devising a new, shorter, easier to use dataset for introduction in 2007/08, subject to formal approval progressing links with Hospital Episode Statistics (HES) patient records to make more data available for analysis for operations carried out on NHS patients in England holding and attending a range of events for stakeholders during 2007/08 the patient record linkage will be extended to NHS patients treated in Wales using Patient Episodes Database Wales (PEDW) a planned extension to the NJR to cover Northern Ireland. 1 Number of operations recorded on NJR relative to sales of implants between 1 April 2006 and 31 March th Annual Report 09

10 Part 2 Part 2 of the NJR 4th Annual Report summarises the data for hip and knee procedures carried out between 1 January to 31 December 2006 in England and Wales and entered into the NJR by 28 February It also includes a description of outcomes after hip and knee replacement, based on procedures entered into the NJR since the start of data collection in April 2003 that were linked to records in the Hospital Episode Statistics database. NJR compliance in 2006 The total number of levies collected between 1 January and 31 December 2006 was 154,066 and the total number of hip or knee replacement procedures reported to the NJR was 122,442 (116,046 in England and 6,396 in Wales). This suggests that the compliance rate was 79% for procedures carried out during the 2006 calendar year in the NHS and the independent sector, which is an improvement compared with 77% in 2005 and 60% in Overview of hip and knee procedures carried out in 2006 In 2006, NHS and independent sector hospitals and treatment centres (392 in England and 23 in Wales) were open and 393 (95%) submitted data to the NJR. On average, 112 hip replacements and 99 knee replacements were recorded per participating healthcare unit. The NJR recorded 61,456 hip replacement procedures, of which 10% were revisions or re-operations, and 60,986 knee replacement procedures, of which 8% were revisions or re-operations undertaken between 1 January and 31 December Of the hip procedures, 65% were carried out in NHS hospitals, 25% in independent hospitals, 5% in NHS treatment centres and 4% in independent sector treatment centres. Corresponding percentages for knee procedures were 67% in NHS hospitals, 21% in independent hospitals, 7% in NHS treatment centres and 5% in independent sector treatment centres. There was an increase in patients with mild or incapacitating disease prior to surgery in primary hip and knee replacement procedures. The percentage of patients with mild disease or more severe comorbidity increased gradually from 68% in 2004 to 76% in 2006 in patients undergoing primary hip replacement, and from 74% in 2004 to 82% in 2006 in patients undergoing primary knee replacement. 155 different brands of acetabular cups and 176 different brands of femoral stems were recorded, compared with 110 cups and 129 stems in 2005 and 88 cups and 101 stems in Of all procedures with the cup and stem brand reported in 2006, 22% used mixed and matched cup-stem combinations. The relative frequencies of the different knee procedure types have largely remained unchanged since brands of total condylar knee prostheses were recorded. In addition, there were 13 brands of unicondylar prostheses, 7 brands of patello-femoral replacement prostheses and 12 brands of hinged prostheses. The number of brands for each prosthesis type remained more or less the same compared with However, there was an increase of about 50% compared with 2004 in the number of brands used for knee replacement. Outcome of hip and knee procedures carried out between 1 April 2003 and 30 September 2006 Revision rates, mortality and length of stay were analysed using data obtained from linkage of the NJR to the Hospital Episode Statistics (HES) database, with special attention given to hip resurfacing and unicondylar knee replacement. The HES database records procedures undertaken in England and includes only patients treated in NHS hospitals, in NHS treatment centres, and those treated in independent hospitals and independent sector treatment centres with NHS funding. When interpreting the revision rates, one should take into account that not all revision procedures that occurred may have been identified through the linkage process. Furthermore, when comparing revision rates with other national registries, one should take into account that there may be differences in the definition of a revision and that re-operations may have been included by some registries. Of all 355,480 hip or knee replacement procedures recorded in HES and carried out between April 2003 and September 2006 at NHS hospitals and NHS treatment centres, or in the independent sector and funded by the NHS, 187,220 (53%) could be linked to the NJR. Linkage was not possible for procedures that were not recorded in the NJR (non-compliance) or for those recorded procedures for which patient identifiers were not available. There has been a trend towards more cementless total hip replacement procedures and fewer cemented procedures since Cementless hip replacements increased gradually from 21% in 2004 to 30% in 2006 and cemented replacements declined from 53% in 2004 to 48% in These are the figures for the calendar year, 1 January 2006 to 31 December 2006 and will vary from figures quoted for the financial year 1 April 2006 to 31 March 2007 elsewhere in the Report 10 National Joint Registry

11 The number of procedures that could be linked differed between provider types. About 70% of hip or knee replacement procedures undertaken at NHS hospitals or NHS treatment centres could be linked, compared with only about a quarter of those carried out at independent sector treatment centres, and less than 10% of those carried out in independent hospitals. Therefore, the HES-linked procedures are most representative of procedures undertaken at NHS hospitals and NHS treatment centres in England. The overall revision rate for primary hip replacement was 0.7% (95% CI 3 : 0.6% to 0.7%) at 1 year and 1.3% (95% CI: 1.2% to 1.5%) at 3 years. Procedure type was found to be the most influential factor on implant survival following primary hip replacement. 1 year revision rates after hip resurfacing (1.6%, 95% CI: 1.3% to 2.0%) were five times higher than cemented total hip replacement (0.3%, 95% CI: 0.3% to 0.4%). After adjusting for patient age, gender, general medical condition and provider type, hip resurfacing procedures were found to still have a statistically significantly higher revision rate (hazard ratio 4.6, 95% CI 3.4 to 6.2) within 1 year compared with cemented total hip replacement. There was evidence that a large number of the failures of hip resurfacing prostheses were in older female patients, indicating the need for careful patient choice. Analysis of longer term survival is necessary to establish the comparative long term performance of hip resurfacing. The average length of hospital stay after a primary hip replacement was 9.1 days. The shortest length of hospital stay was found in patients undergoing hip resurfacing, with an average stay of 6.3 days. Following primary knee replacement, patients stayed on average 8.1 days in hospital. After unicondylar knee replacement, length of stay was only 5.9 days. In this Report it was possible to present analyses of short-term outcomes only up to 3 years following primary hip or knee replacement on account of length of follow-up that the NJR allows at the present time. Analysis of longer term outcomes are necessary to establish whether the results seen persist. Furthermore, the analyses were based on data obtained from the linkage of NJR with HES, an exercise that was undertaken for the first time in this Report and in which linkage was not possible for all recorded procedures. The results presented should be interpreted with these factors in mind. The overall revision rate for primary knee replacement was 0.4% (95% CI 0.3% to 0.4%) at 1 year and 1.4% (95% CI: 1.2% to 1.6%) at 3 years. Revision rates at 1 year were similar between cemented total knee and unicondylar knee primary replacements. 0.3% of cemented knee replacements needed revision within 1 year, compared with 0.4% of unicondylar knee replacements. Mortality at 1 year was 1.9% after hip replacement and 1.6% after knee replacement, which is less than half of that observed in the age-matched and sex-matched general population in England and Wales. These differences demonstrate that patients who undergo hip or knee joint replacement are a highly select group. A thromboprophylaxis regime was prescribed for 74,868 (98%) of primary hip replacement patients and 76,581 (98%) of primary knee replacement patients. There was no difference in mortality up to 1 year following primary hip or knee replacement between patients for whom thromboprophylaxis was prescribed and patients for whom none was prescribed. 3 CI: Confidence Interval (Statistical Term) 4th Annual Report 11

12 Part 1 1. Introduction 12 National Joint Registry

13 1.1 Annual Report This is the fourth annual report of the National Joint Registry (NJR), which provides information about hip and knee replacement operations in England and Wales within both the NHS and independent healthcare sector. This information is valuable to surgeons, patients, members of the public and the manufacturers of hip and knee implants (artificial joints). NJR collects information that can be used to help improve care and treatment through information on surgical practice and on the hip and knee implants used in joint replacement surgery. The Report has been divided into two sections for ease of reference - a general outline of the work on the NJR and an analysis of the operations recorded by the Registry. Part 1 a review of progress made on the NJR during the financial year 1 April 2006 to 31 March 2007 and its plans to increase still further the value of its information in the future. Part 2 an analysis of the data recorded in the calendar year 1 January and 31 December 2006 and, using information recorded on NJR since April 2003, it focuses on: linked primary and revision operations; hip resurfacing; unicondylar knee replacement and mortality rates. The quality of the information received is very important to the NJR as it affects the level of detail the NJR is able to give to those who are interested in its findings (a list of stakeholders can be found in Section 2.5). To support the collection and use of data, it is important that data collection and entry into NJR is made as easy as possible and that information held on NJR is available when required (see Section 2.4 for developments in these areas) Management and funding The NJR has been managed by Northgate Information Solutions (UK) Ltd since April 2006, under a contract with the Department of Health, and is funded through a levy raised on the sale of hip and knee replacement implants (further information regarding funding is available in Section 5 Part 2). The NJR s Steering Committee (NJRSC), which was set up in October 2002, is an advisory non-departmental public body. A list of NJRSC members and members declarations of interest is contained in Appendix 1 with the Terms of Reference detailed in Appendix 2. Further information about the NJRSC s work during 2006/07 is featured in Section The National Joint Registry The NJR was set up in October 2002 and began collecting data on hip and knee replacement operations in April The NJR was set up to improve patient care by finding out more about hip and knee joint replacement implants and surgery. It is doing this by building up a database of information. The aim is for the Registry to be able to provide information for patients, surgeons, hospitals, manufacturers and healthcare regulatory agencies on implant performance, joint replacement surgery and best surgical practice. The NJR can only achieve its aims if it has a timely and continuous supply of high quality information about the operations that are carried out. This information makes it possible to monitor the performance and long-term effectiveness of hip and knee replacement surgery and the implants, known as prostheses, used. The information on NJR is made available to surgeons, patients, the public and the manufacturers of replacement joints to help improve care and treatment in the future. Data is provided to the NJR by NHS and independent healthcare providers throughout England and Wales. By 31 March 2007 it had received 433,319 records. 4th Annual Report 13

14 Part 1 2. Progress 14 National Joint Registry

15 2.1 Challenges The success of the NJR is reliant on meeting three main challenges: improving the completeness and quality of the information held on the Registry; reducing the burden of data entry on hospitals and units supplying the information and making information held on NJR available for better patient care. The continuing challenges on data completeness and quality are to ensure: all hip and knee joint replacement operations carried out in England and Wales are recorded on the NJR the recorded information is of good quality patient consent is given for data to be stored and used to achieve the aims of the NJR. Over the last four years the level at which these data challenges have been met has increased significantly (see point 2.2). During 2006/07 the NJR Centre improved the way in which on-site support to individual NHS and independent healthcare hospitals and treatment centres (known as units) is managed and prioritised. (Examples of these improvements are detailed at Section 2.5 under the heading, Regional Coordinators). There are three ways of measuring these areas of data quality and completeness: compliance the percentage of records submitted to the NJR compared with the total number of hip and knee replacement operations carried out in England and Wales, also referred to as case ascertainment target 95% by June 2008 consent the percentage of records submitted to the NJR with consent given by patients for use of their personal information 4 target 90% by June 2008 linkability the percentage of records that have patient consent and the patient s NHS number so that all operations performed on the same patient can be linked. The goals of the NJR will only be achieved if operations on the same patient can be successfully linked target 90% by June In addition to addressing these targets, the NJR Centre s work during 2006/07 centred on: making it easier for records to be submitted sharing best practice through workshops for staff involved in the administration of NJR in NHS and independent healthcare units and encouraging them to share ideas. Regional Coordinators have also been active in sharing information about the most effective processes during their visits to units where submission of data to NJR is poor making information more easily accessible to surgeons, staff in units using the NJR and hospital management. NJR ReportsOnline has been implemented, giving local, summary information about the NJR, for example, case mix and implant usage for surgeons. Reports have been designed for hospital managers and will be implemented in 2007/08 improving performance monitoring. These initiatives, which are designed to help ensure that the commitment of stakeholders to NJR is maintained, will be progressed further during the year ahead. More work will be undertaken to improve still further the information available to stakeholders, for example, through the links being developed with other NHS systems. 2.2 Progress Progress on these challenges during 2006/07 is considered across the different areas Data completeness and quality compliance All NHS and independent healthcare units in England and Wales are asked to submit details of their hip and knee replacement operations. The method used to monitor compliance with this request is to compare the number of levies raised from the sale of implants to the number of submissions from units. Figure 1(overleaf) illustrates the compliance rate (case ascertainment) across all units over the last four years. Compliance increased significantly over the first three years of the NJR. In 2003/04, from 156,354 operations 5 which took place, 62,191 operations were recorded on the NJR giving a compliance rate of approximately 40%, but by 2005/06, the rate had risen to 82%, 132,578 of 161,000 operations. The rate decreased slightly during 2006/07 to 81.3%, 131,378 of just under 158,000 operations against an apparent decrease in the number of operations performed in England and Wales based on the levies collected from implants sold. Of the units expected to submit data to the NJR 11 failed to submit any records during 2006/07. These are listed in Appendix 6. 4 Personal information includes NHS number, surname, date of birth and postcode 5 Operations this is an estimate of the number of hip and knee joint replacement operations performed in England and Wales based on the number of levies collected on implants sold 6 This is for the financial year from 1 April 2006 to 31 March th Annual Report 15

16 NJR Records 180, , , , ,000 80,000 60,000 90% 80% 70% 60% 50% 40% 30% Consent Rate (%) Figure 1 NJR Compliance: , based on levies from implant sales Source: Operations entered on NJR 1 April March 2007 and levy submissions to NJR by implant suppliers and manufacturers. For supporting data see Appendix 7 40,000 20, / /05 Year 2005/ /07 20% 10% 0 % Number of NJR Operations Levy Compliance Consent Why is it important for patients to give consent? By consenting to the inclusion of their personal details on the NJR database, patients enable more accurate study of the outcomes of hip and knee replacement operations. In turn, this means the NJR is able to provide information that can be used to: improve awareness of the outcomes of replacement surgery help patients obtain the best clinical care for joint replacement surgery look at the performance of implants and help identify any brand of implant showing high failure rates improve surgical practice including information that can be used to identify best surgical practice help NHS and other healthcare organisations to make best use of their resources. Patients must give consent for their personal details to be used on the NJR database and once they understand the purpose of the NJR, they rarely refuse to give consent when asked. Recording a patient s personal details, including their NHS number, enables the linking of operations for that patient that have either been carried out already or may be carried out in the future. This will enable problems either with implants or surgical techniques to be identified at an early stage and the appropriate action taken. This information on NJR will also enable hospitals to be identified and assisted when they need to recall patients who have received an implant that is suspected of failing to perform as expected. The rates of patient consent are published monthly on the NJR website in NJR StatsOnline ( The percentage of records submitted to the NJR with the necessary consent rose from 78% (29,238 of 37,416 NJR records) in 2005/06 Quarter 4 (1 January to 31 March 2006), to 83% (30,746 of 36,862 NJR records) in 2006/07 Quarter 4 (1 January to 31 March 2007). Figure 2 (right) shows the pattern of patient consent over the last four years. A consent rate of approximately 64%, 39,433 from 61,781 recorded operations was reported in the NJR s first year; this dipped to below 60%,16,273 of 27,249 recorded operations during the second quarter of 2004/05 but it has risen virtually every quarter since then. Further improvement is needed in order to achieve the target of 90% by June At present, when submitting records, participating units may choose from three options for patient consent: yes, no and don t know. During 2006/07, of 131,378 records submitted to the NJR, 6% (7,680) included a no response and 13% (16,551) don t know. It is likely that many of the don t know and no responses arise because either the patient has not been asked for consent or the completed consent form was not available at the time of entering the record. 16 National Joint Registry

17 Figure 2 Number of operations on NJR and number with consent 40,000 35,000 30,000 25,000 20,000 15,000 10,000 90% 80% 70% 60% 50% 40% 30% 20% Consent Rate (%) NJR Consent: quarterly analysis of total records received and those with patient consent, 2003/ /07 Source: Operations entered on NJR 1 April March For supporting data see Appendix 7 5,000 10% Number of Operations 0 0 % Number of Consent Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 2003/ / / /07 Consent Rate Section 60 exemption During the year in view, the NJR Centre was granted exemption 7 by the Patient Information Advisory Group (PIAG) from some of the requirements of the Health and Social Care Act 2001, Section 60. This means that for all the records submitted to NJR with a don t know response regarding consent, a patient s personal details may be recorded for the purposes of improving linkability of NJR records with other records on the same patient. However, if a patient later refuses consent, their personal details will be removed from the NJR records. The data entry system was altered on 31 March 2007 to support this change. The exemption is retrospective, enabling the NJR Centre to begin to improve the linkability of previous years records Changes to the consent process The NJR Centre has been looking at ways to help units with the patient consent process. During 2006/07 it was confirmed that NJR consent can be sought at the same time as consent to operate, providing it is made clear to patients that receiving treatment is not dependent on giving consent for their data to be stored on the NJR. This removes the problems associated with having to seek consent from patients for their personal details to be placed on the NJR at a different time from their consent to operate. Work has started on local consent to operate forms to enable units to have approved text which they can add to their own, local consent to operate forms Linkability Linkability enables comparisons to be drawn between operations, for example, by looking at the primary (first) hip or knee joint replacement operation and the subsequent revisions or re-operations on the same joint in the same patient. The accuracy of findings from the NJR depends on having a sufficiently high number of NJR records containing patient information that will allow the NJR record to be linked to another record of the same patient. In order for records to be linked, patient consent is required for the storage of personal information. Records must include either the patient s NHS number or their surname, date of birth and postcode, so that the NHS number can be traced through the National Strategic Tracing Service (NSTS). The percentage of linkable records held on the NJR from 2003/04 to 2006/07 is shown in Figure 3. The level has improved significantly from 45% (27,807) of the 61,781 records submitted in 2003/04 to 60% (79,733) of 132,191 records two years later in 2005/06 and 69% (90,502) of 130,927 records submitted in 2006/07. Further work will be needed to reach the target of 90% by June Plans include use of mandatory information on the data collection form and using other NHS databases (HES and PEDW) to help find the NHS number. 7 This is an annual exemption and has to be re-applied for each year 4th Annual Report 17

18 140,000 80% Figure 3 Number of records submitted and with NHS number after NSTS search 120, ,000 80,000 60,000 40,000 20,000 70% 60% 50% 40% 30% 20% 10% NJR Linkability: analysis of total records received and those for which NHS numbers have been traced, 2003/ /07 Source: Operations entered on NJR 1 April March For supporting data see Appendix / /05 Year 2005/ /07 0 % Number of Operations Number with NHS Number LinkageRate 2.3 Key Figures On the record NJR records include the following information about each operation: patient details (if patient consent is recorded) hospital surgeon operation surgical approach any untoward event which may have occurred during the operation Operation totals Since the launch of the NJR in April 2003, a total of 433,319 hip and knee joint replacement operations in England and Wales has been recorded on the NJR. During the first year, 2003/04, the number of operations reported was 62,189; with this rising to 107,172 in 2004/05 and 132,577 in 2005/06. However, in 2006/07, the figure for the year dropped slightly, to 131,378, which is 1,199 (0.9%) fewer than the previous year. This represents a minor decrease in compliance (fewer operations recorded on NJR). See Appendix 7 for supporting data. Figure 4 (right) shows the total number of operations recorded on NJR in England and Wales each year from 2003/04 to 2006/07. It shows that the figures for Wales have increased each year and that, in 2006/07, for the first time, the number of knee joint replacement operations was greater than the number of hip joint replacement operations in both countries. In England, during 2006/07, 61,940 knee operations and 61,849 hip operations were recorded on the NJR; whilst in Wales, the figures were 3,683 for hip operations and 3,906 for knee operations. 18 National Joint Registry

19 Number of Operations 70,000 60,000 50,000 40,000 30,000 20,000 Figure 4 Total: hip and knee joint replacement operations entered on the NJR, 2003/04 to 2006/07, recorded by country in which the operation took place Source: Operations entered on NJR 1 April March ,000 0 England Hip Wales Hip 2003/04 32, /05 53,513 1, /06 63,595 2, /07 61,849 3,683 England Hip Wales Hip England Knee 28,450 50,606 62,959 61,940 England Knee Wales Knee 692 1,448 3,033 3,906 Wales Knee Operations by year and country Total operations: 2003/04 62, /05 107, /06 132, /07 131, Operation types Hip and knee joint replacement operations take three forms: primary the first time a joint is replaced revision an operation that involves the removal and replacement of one or more components of a joint replacement The greatest number of operations is of the primary kind. In 2006/07, for example, 121,102 (92%) of the 131,378 operations recorded were primary operations; only 9,592 (7%) were revisions and 684 (0.5%) re-operations. During the NJR s first two years, the number of primary hip joint replacement operations that were recorded outnumbered the number of primary knee joint replacement operations recorded; however, that trend was reversed in both 2005/06 and 2006/07. In 2005/06 primary knee joint replacement operations exceeded primary joint replacement hip operations by more than 2,500 (4.4%) and last year, this figure rose to more than 3,000 (5.4%). Figure 5 (overleaf) shows the number of operations by type from 2003/04 to 2006/07. (Note, hip and knee joint replacement re-operations where not collected in 2003/04). re-operation other than revision - an operation following either a primary or revision operation that does not require any joint implants to be removed or replaced, for example, if an implant needs to be re-aligned or has become loose. 4th Annual Report 19

20 Number of Operations 70,000 60,000 50,000 40,000 30,000 20,000 Figure 5 Type: hip and knee joint replacement operations entered on the NJR, 2003/04 to 2006/07, recorded by type of operation Source: Operations entered on NJR 1 April March , / / / /07 Hip Primary Hip Primary Knee Primary Revision Hip Revision Knee Hip Re-operation Knee Re-operation 30,036 27,911 3,012 1,232 n/a n/a 49,687 49,567 5,186 2, ,000 62,616 6,237 3, ,952 62,150 6,272 3, Knee Primary Revision Hip Revision Knee Hip Re-operation Knee Re-operation Operations by year and joint/type Total operations: 2003/04 Hip: 33,048 Knee: 29, /05 Hip: 55,118 Knee: 52, /06 Hip: 66,585 Knee: 65, /07 Hip: 65,532 Knee: 65, Where did the operations take place? In total, of the 433,319 operations recorded over the last four years, 415,133 (96%) were carried out in England and 18,183 (4%) in Wales. During 2006/07, England carried out 123,789 (94%) and Wales 7,589 (6%), as shown in Figure 4 (above). Patients in England may have their hip and knee joint replacement operations with one of four different types of organisation: NHS hospital NHS Treatment Centre Independent healthcare hospital Independent Treatment Centre There are no NHS or independent treatment centres in Wales. To date, most of the 433,319 operations recorded on NJR were carried out in an NHS hospital: 264,578 (61% of all operations) in England and 13,905 (3% of all operations) in Wales. Independent healthcare hospitals have undertaken 119,590 (28%) of the recorded operations in England and 4,278 (1%) in Wales. The number of hip and knee joint replacement operations 20 National Joint Registry