International Vascunet Validation of the Swedvasc Registry

BACKGROUND:

International comparison of registry data within vascular surgery has previously been published by Vascunet. One of the limitations of such comparisons is data validity and completeness, and meaningful interpretation of differences between countries can only be made if the data are robust within each of the countries studied. The Vascunet collaboration has therefore embarked on a validation exercise of international vascular registry data.

METHODS:

Five out of 20 hospitals performing vascular surgery in Sweden were visited by two international validators. Independent evaluation of the procedures of carotid endarterectomy and infrarenal abdominal aortic aneurysm repair was performed, and local hospital administrative data were compared with Swedvasc registry data. External validation compared the numbers of cases in these two systems of data collection and internal validation compared data accuracy and completeness within individual patient records.

RESULTS:

Hospital records identified 335 carotid and 393 abdominal aortic aneurysm (AAA) procedures, whereas Swedvasc identified 331 carotid and 359 AAAs. Nine carotid procedures and 64 AAA procedures were found in hospital administrative data but not in Swedvasc, and 14 carotids and 30 AAAs were found in Swedvasc but not in hospital data. External validity was 100% (95% CI 98.8-100%) for carotids and 98.8% (95% CI 96.9-99.5%) for AAAs. In internal validation, 0.8% of variables were missing in hospital data compared with Swedvasc and 4.2% were missing in Swedvasc compared with hospital data. Data contained within the data fields of Swedvasc and hospital data were the same in 97.4% (95% CI 96.3-98.3%) for carotids and 96.2% (CI 94.9-97.2%) for AAAs.

CONCLUSION:

This study has provided a template for international validation of registry data and has demonstrated that Swedvasc is a highly accurate system of data collection for Swedish vascular surgery.

Link: https://www.ncbi.nlm.nih.gov/pubmed/26338474

Regional Differences in Case Mix and Peri-operative Outcome After Elective Abdominal Aortic Aneurysm Repair in the Vascunet Database

OBJECTIVE/BACKGROUND:

National differences exist in the outcome of elective abdominal aortic aneurysm (AAA) repair. The role of case mix variation was assessed based on an international vascular registry collaboration.

METHODS:

All elective AAA repairs with aneurysm size data in the Vascunet database in the period 2005-09 were included. AAA size and peri-operative outcome (crude and age adjusted mortality) were analysed overall and in risk cohorts, as well as per country. Glasgow Aneurysm Score (GAS) was calculated as risk score, and patients were stratified in three equal sized risk cohorts based on GAS. Predictors of peri-operative mortality were analysed with multiple regression. Missing data were handled with multiple imputation.

RESULTS:

Patients from Australia, Finland, Hungary, Norway, Sweden and the UK (n = 5,895) were analysed; mean age was 72.7 years and 54% had endovascular repair (EVAR). There were significant variations in GAS (lowest = Finland [75.7], highest = UK [79.4], p for comparison of all regions < .001), proportion of AAA < 5.5 cm (lowest = UK [6.4%], highest = Hungary [29.0%]; p < .001), proportion undergoing EVAR (lowest = Finland [10.1%], highest = Australia [58.9%]; p < .001), crude mortality (lowest = Norway [2.0%], highest = Finland [5.0%]; p = .006), and age adjusted mortality (lowest = Norway [2.5%], highest = Finland [6.0%]; p = .048). Both aneurysm size and peri-operative mortality were highest among patients with a GAS >82. Of those with a GAS >82, 8.4% of men and 20.8% of women had an AAA <5.5 cm.

CONCLUSION:

Important regional differences exist in case selection for elective AAA repair, including variations in AAA size and patient risk profile. These differences partly explain the variations in peri-operative mortality. Further audit is warranted to assess the underlying reasons for the regional variation in case-mix.

Link: https://www.ncbi.nlm.nih.gov/pubmed/25752419

Quality Improvement in Vascular Surgery: The Role of Comparative Audit and Vascunet

Most nations with developed healthcare systems have a strong interest in audit, both for financial and clinical quality control. Whereas financial control has been a key political requirement for managing healthcare, the use of clinical outcome data has, until recently, taken more of a back seat.

Clinical audit has a long history of describing outcomes and challenging established attitudes or practice.1 Responses to published audits vary. Some clinicians voice criticism of bias as a result of selective reporting, either from a few units, or because of incomplete datasets.2 Attitudes have gradually changed with improved understanding of the role of audit as a tool to examine and refine standards of practice.3 This has been accompanied by a growth in clinical audit across all branches of medicine.

The turn of the century marked a shift towards more widespread clinical audit, with development of political interest in using quality to justify or contain costs. The advent of organisations such as the National Institute for Clinical Excellence (NICE) in the UK saw a growth in the use of research and audit to set standards both for outcomes and processes of care. A good example of this in vascular surgery is the NICE clinical guideline 68, which sets out clear standards for assessment, referral, and treatment of patients with TIA and minor stroke.4 These standards are incorporated into national audits in Europe and reporting now encompasses both outcomes and performance indicators such as timeliness of surgery and cranial nerve injury.5 Such reporting has driven improvement in quality of services by focussing clinicians on key components of high-quality pathways of care.

Vascunet was formed in 1997 as a collaboration of national registries in Europe, New Zealand, and the state of Victoria in Australia, with its first report produced in 2007.6, 7 Since then, the Vascunet group have published comparative data on carotid surgery,8, 9 abdominal aortic aneurysm,10 lower limb bypass,11 and popliteal artery aneurysm.12 One of the key features of these publications has been to describe the variation in clinical practice across neighbouring countries, notable examples being rates of surgery for asymptomatic stenosis and rates of lower limb bypass for intermittent claudication. Variation in outcomes is also reported at a national level.

The value of such reporting was demonstrated by the 2008 Vascunet report. This demonstrated outlying mortality rates after elective repair of abdominal aortic aneurysm surgery in the UK.13 This was a stimulus to a quality improvement initiative14 that sought to standardise practice and improve outcomes. The transparent publication of standards led to their widespread adoption both by clinicians and service commissioners within the UK. Recent publications have demonstrated a marked improvement in UK outcomes.15 This cycle of audit, analysis, standard setting, and re-audit demonstrates the improvement in quality that can follow acknowledgement of poor outcomes. This experience mirrors those in other clinical specialities such as cardiothoracic surgery.

Comparative audits suffer from a number of shortcomings, such as incomplete datasets with potential for bias and misleading interpretation. Most national registries rely on voluntary data contributions from practising clinicians who have varying levels of enthusiasm for audit. It is widely acknowledged that incomplete audit data is a source of bias and may give misleading messages. This has allowed some to ignore the messages from comparative audit, and may be the explanation behind some countries not wishing to participate in data analysis and publication. The recognition of this issue leads to the linking of Swedvasc (and the Helsinki datasets in Finland) data to national administrative datasets to improve accuracy. Similarly in the UK, data for carotid and aortic aneurysm procedures are now compared with national administrative datasets to demonstrate the quality of data. A secondary benefit has been an improvement in data quality, presumably as a result of peer pressure.

Vascunet has recently taken this further with external validation of data subsets in Hungary 16 and Sweden (ongoing project). This pilot demonstrated that national datasets can be validated by expatriate experts, providing an independent and even more robust measure of data quality. It is planned to extend this throughout the Vascunet registries group, if funding can be found.

Clinical audit data is one important source of information, about routine clinical practice, that can be used to highlight inconsistencies in clinical outcomes. The use of data, however incomplete, as an agent for change and as a guide for standard setting is established. We believe that the use of national audit data should be extended to drive quality improvement across geographical boundaries.

There are significant challenges to achieving this, but Vascunet believes that the time is right to embrace this. With increasing financial constraints on healthcare, clinicians need to be seen to lead on issues of quality of care. Part of this requires an open approach to measuring the standards of care, with the aim of improvement, rather than criticism. We believe that we have the support of patients in this aim and that transparent publication of data serves to both inform and educate in the debate about allocation of limited resources.

There is debate about what and how much data should be collected. Most enthusiasts approach clinical audit wishing to obtain a large amount of data to enable a detailed analysis of behaviour. The problem with this approach is that it inevitably relies on busy clinicians collecting the data, often after delivery of care. Unsurprisingly, the levels of enthusiasm for this vary hugely, with some seeing it as an intrusion on their relationship with the patient. The end result is incomplete and unreliable datasets and limited reporting.

An alternative is to collect small amounts of data about critical steps in the patient pathway of care. Such “key performance indicators” (KPI) can be linked to nationally collected administrative data to provide a moderately detailed account of the process of care. An example of this is seeking both outcome data (stroke and death) following carotid endarterectomy and collecting data on symptom to treatment time, to provide a more balanced picture of the quality of care. The resultant “less is more” approach allows for small datasets to provide important information to clinicians.

A number of factors determine how effective clinical audit is at changing clinician behaviours and patient outcomes. There is now a growing science around audit and feedback.17, 18 This states some factors that seem self-evident. For example there is evidence that audit and feedback can be made more effective by setting explicit goals and having a clear and realistic action plan, based on evidence about best practice. There needs to be clarity about the changes required and a commitment to multiple feedback cycles, with availability of peer group data for comparison. Repeated feedback delivered in both written and verbal format by people perceived to be part of the clinical team (i.e. part of the professional group) is much more effective in bringing about change than delivery by outside agencies (e.g. departments of health, commissioners of care). We believe that Vascunet can fill this role as it is made up of representatives from all participating audits.

Open reporting of data in a manner designed to support and encourage change, can be used to drive quality improvement by focussing on a small number of measures associated with a quality service. This has now been happening in many countries for some years. This approach has been used successfully for some years in Sweden, the UK and parts of the USA to demonstrate the quality of service and drive up standards by placing this in the public domain. The focus has been on care delivery within each country. We believe that the next step is for outcomes data analysis and quality improvement in vascular surgery to cross national boundaries, by common reporting of KPI for core vascular procedures. This is why Vascunet has begun validating national registries and has formed links with the North American Society of Vascular Surgery Quality Initiative (SVS-QI).

What is now required is clinical support to agree that it is in both our and our patients’ best interests to support a broadening of clinical audit to provide quality feedback across Europe. This will involve defining agreed datasets and seeking financial support to set up a data centre for analysis and reporting. Data collection should remain a local activity, owned by units and national societies, each committed to collaboration within the Vascunet group. We believe that the time is ripe to use the European registry experience to develop quality improvement initiatives throughout the European society nations and share our experiences openly to the benefit of our patients and clinical practices.

Link: https://www.ncbi.nlm.nih.gov/pubmed/26347910

Validation of the VASCUNET registry – pilot study

BACKGROUND:

VASCUNET is an international registry of vascular surgical (open and endovascular) procedures since 1997. The aim of this paper is to describe a pilot validation performed at three hospitals in Hungary in September 2012.

PATIENTS AND METHODS:

Three core indications were checked: abdominal aortic aneurysm, carotid artery disease and limb ischemia with infrainguinal treatment.

RESULTS:

2439 registered procedures had been reported with between 94 and 109 per cent agreement with hospital administrative numbers. In a random sample of 29 patients the VASCUNET data were compared with the patient records regarding risk factors, procedures performed and in hospital results. Only few discrepancies were found.

CONCLUSIONS:

The conclusions are that validation is feasible, that this pilot project in Hungary showed good agreement between registry and local patient records. For a registry to be accepted and used both for practical and scientific purposes regular validation by senior surgeons should be undertaken and the vascular surgical community must have a budget for such a process.

Link: https://www.ncbi.nlm.nih.gov/pubmed/24627320

Editor’s Choice: Contemporary treatment of popliteal artery aneurysm in eight countries: A Report from the Vascunet collaboration of registries

OBJECTIVES:

To study contemporary popliteal artery aneurysm (PA) repair.

METHODS:

Vascunet is a collaboration of population-based registries in 10 countries: eight had data on PA repair (Australia, Finland, Hungary, Iceland, New Zealand, Norway, Sweden, and Switzerland).

RESULTS:

From January 2009 until June 2012, 1,471 PA repairs were registered. There were 9.59 operations per million person years, varying from 3.4 in Hungary to 17.6 in Sweden. Median age was 70 years, ranging from 66 years in Switzerland and Iceland to 74 years in Australia and New Zealand; 95.6% were men and 44% were active smokers. Elective surgery dominated, comprising 72% of all cases, but only 26.2% in Hungary and 39.7% in Finland, (p < .0001). The proportion of endovascular PA repair was 22.2%, varying from 34.7% in Australia, to zero in Switzerland, Finland, and Iceland (p < .0001). Endovascular repair was performed in 12.2% of patients with acute thrombosis and 24.1% of elective cases (p < .0001). A vein graft was used in 87.2% of open repairs, a synthetic or composite graft in 12.7%. Follow-up was until discharge or 30 days. Amputation rate was 2.0% overall: 6.5% after acute thrombosis, 1.0% after endovascular, 1.8% after open repair, and 26.3% after hybrid repair (p < .0001). Mortality was 0.7% overall: 0.1% after elective repair, 1.6% after acute thrombosis, and 11.1% after rupture.

CONCLUSIONS:

Great variability between countries in incidence of operations, indications for surgery, and choice of surgical technique was found, possibly a result of surgical tradition rather than differences in case mix. Comparative studies with longer follow-up data are warranted.

Link: https://www.ncbi.nlm.nih.gov/pubmed/24287153

International variations in infrainguinal bypass surgery – a VASCUNET report

OBJECTIVES:

To compare practice in lower limb bypass surgery in nine countries.

DESIGN:

A prospective study amalgamating and analysing data from national and regional vascular registries.

METHODS:

A table of data fields and definitions was agreed by all member countries of the Vascunet Collaboration. Data from January 2005 to December 2009 was submitted to a central database.

RESULTS:

32,084 cases of infrainguinal bypass (IIB) in nine countries were analysed. Procedures per 100,000 population varied between 2.3 in the UK and 24.6 in Finland. The proportion of women varied from 25% to 43.5%. The median age for all countries was 70 for men and 76 for women. Hungary treated the youngest patients. IIB was performed for claudication for between 15.7% and 40.8% of all procedures. Vein grafts were used in patients operated on for claudication (52.9%), for rest pain (66.7%) and tissue loss (74.1%). Italy had the highest use of synthetic grafts. Among claudicants 45% of bypasses were performed to the below knee popliteal artery or more distally. Graft patency at 30 days varied between 86% and 99%.

CONCLUSIONS:

Significant variations in practice between countries were demonstrated. These results should be interpreted alongside the known limitations of such registry data with respect to quality and completeness of the data. Variation in data completeness and data validation between countries needs to be improved for useful international comparison of outcomes.

Link: https://www.ncbi.nlm.nih.gov/pubmed/22658613

Variation in clinical practice in carotid surgery in nine countries 2005-2010. Lessons from VASCUNET and recommendations for the future of national clinical audit

OBJECTIVES:

The aim of the study was to analyse variation in carotid surgical practice, results and effectiveness in nine countries.

PATIENTS AND METHODS:

A total of 48,185 carotid endarterectomies (CEAs) and 4602 carotid artery stenting (CAS) procedures were included in the comparison. A theoretical effectiveness of CEA provision for each country was estimated.

RESULTS:

92.6% of the CEAs were performed according to the inclusion criteria based on the current European recommendations and had a theoretical benefit for the patient. The indication for surgery was symptomatic stenosis in 60.1% and this proportion varied between 31.4% in Italy and 100% in Denmark. The overall combined stroke and death rate in symptomatic patients was 2.3%. This varied between rates of 0.9% in Italy and 3.8% in Norway. The overall combined stroke and death rate in asymptomatic patients was 0.9%. It was lowest in Italy at 0.5%, and highest in Sweden at 2.7%. We estimated that the stroke prevention rate per 1000 CEAs varied from 72.9 in Italy to 130.8 in Denmark.

CONCLUSIONS:

There is significant variation in clinical practice across the participating countries. The theoretical stroke prevention potential of CEA seems to vary between participating countries due to differences in the inclusion criteria.

Link: https://www.ncbi.nlm.nih.gov/pubmed/22633072

Treatment of abdominal aortic aneurysm in nine countries 2005-2009: a vascunet report

OBJECTIVES:

To study contemporary treatment and outcome of abdominal aortic aneurysm (AAA) repair in nine countries.

DESIGN AND METHODS:

Data on primary AAA repairs 2005-2009 were amalgamated from national and regional vascular registries in Australia, Denmark, Finland, Hungary, Italy, Norway, Sweden, Switzerland and the UK. Primary outcome was in-hospital or 30-day mortality. Multivariate logistic regression was used to assess case-mix.

RESULTS:

31,427 intact AAA repairs were identified, mean age 72.6 years (95% CI 72.5-72.7). The rate of octogenarians and use of endovascular repair (EVAR) increased over time (p < 0.001). EVAR varied between countries from 14.7% (Finland) to 56.0% (Australia). Overall perioperative mortality after intact AAA repair was 2.8% (2.6-3.0) and was stable over time. The perioperative mortality rate varied from 1.6% (1.3-1.8) in Italy to 4.1% (2.4-7.0) in Finland. Increasing age, open repair and presence of comorbidities were associated with outcome. 7040 ruptured AAA repairs were identified, mean age 73.8 (73.6-74.0). The overall perioperative mortality was 31.6% (30.6-32.8), and decreased over time (p = 0.004).

CONCLUSIONS:

The rate of AAA repair in octogenarians as well as EVAR increased over time. Perioperative outcome after intact AAA repair was stable over time, but improved after ruptured repair. Geographical differences in treatment of AAA remain.

Link: https://www.ncbi.nlm.nih.gov/pubmed/21775173