Quality of Data Reported on Abdominal Aortic Aneurysm Repair—A Comparison between a National Vascular and a National Administrative Registry

Configuration of vascular services: a multiple methods research programme

Background

Vascular services is changing rapidly, having emerged as a new specialty with its own training and specialised techniques. This has resulted in the need for reconfiguration of services to provide adequate specialist provision and accessible and equitable services.

Objectives

To identify the effects of service configuration on practice, resource use and outcomes. To model potential changes in configuration. To identify and/or develop electronic data collection tools for collecting patient-reported outcome measures and other clinical information. To evaluate patient preferences for aspects of services other than health-related quality of life.

Design

This was a multiple methods study comprising multiple systematic literature reviews; the development of a new outcome measure for users of vascular services (the electronic Personal Assessment Questionnaire – Vascular) based on the reviews, qualitative studies and psychometric evaluation; a trade-off exercise to measure process utilities; Hospital Episode Statistics analysis; and the development of individual disease models and a metamodel of service configuration.

Setting

Specialist vascular inpatient services in England.

Data sources

Modelling and Hospital Episode Statistics analysis for all vascular inpatients in England from 2006 to 2018. Qualitative studies and electronic Personal Assessment Questionnaire – Vascular evaluation with vascular patients from the Sheffield area. The trade-off studies were based on a societal sample from across England.

Interventions

The data analysis, preference studies and modelling explored the effect of different potential arrangements for service provision on the resource use, workload and outcomes for all interventions in the three main areas of inpatient vascular treatment: peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. The electronic Personal Assessment Questionnaire – Vascular was evaluated as a potential tool for clinical data collection and outcome monitoring.

Main outcome measures

Systematic reviews assessed quality and psychometric properties of published outcome measures for vascular disease and the relationship between volume and outcome in vascular services. The electronic Personal Assessment Questionnaire – Vascular development considered face and construct validity, test–retest reliability and responsiveness. Models were validated using case studies from previous reconfigurations and comparisons with Hospital Episode Statistics data. Preference studies resulted in estimates of process utilities for aneurysm treatment and for travelling distances to access services.

Results

Systematic reviews provided evidence of an association between increasing volume of activity and improved outcomes for peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. Reviews of existing patient-reported outcome measures did not identify suitable condition-specific tools for incorporation in the electronic Personal Assessment Questionnaire – Vascular. Reviews of qualitative evidence, primary qualitative studies and a Delphi exercise identified the issues to be incorporated into the electronic Personal Assessment Questionnaire – Vascular, resulting in a questionnaire with one generic and three disease-specific domains. After initial item reduction, the final version has 55 items in eight scales and has acceptable psychometric properties. The preference studies showed strong preference for endovascular abdominal aortic aneurysm treatment (willingness to trade up to 0.135 quality-adjusted life-years) and for local services (up to 0.631 quality-adjusted life-years). A simulation model with a web-based interface was developed, incorporating disease-specific models for abdominal aortic aneurysm, peripheral arterial disease and carotid artery disease. This predicts the effects of specified reconfigurations on workload, resource use, outcomes and cost-effectiveness. Initial exploration suggested that further reconfiguration of services in England to accomplish high-volume centres would result in improved outcomes, within the bounds of cost-effectiveness usually considered acceptable in the NHS.

Limitations

The major source of evidence to populate the models was Hospital Episode Statistics data, which have limitations owing to the complexity of the data, deficiencies in the coding systems and variations in coding practice. The studies were not able to address all of the potential barriers to change where vascular services are not compliant with current NHS recommendations.

Conclusions

There is evidence of potential for improvement in the clinical effectiveness and cost-effectiveness of vascular services through further centralisation of sites where major vascular procedures are undertaken. Preferences for local services are strong, and this may be addressed through more integrated services, with a range of services being provided more locally. The use of a web-based tool for the collection of clinical data and patient-reported outcome measures is feasible and can provide outcome data for clinical use and service evaluation.

Future work

Further evaluation of the economic models in real-world situations where local vascular service reconfiguration is under consideration and of the barriers to change where vascular services do not meet NHS recommendations for service configuration is needed. Further work on the electronic Personal Assessment Questionnaire – Vascular is required to assess its acceptability and usefulness in clinical practice and to develop appropriate report formats for clinical use and service evaluation. Further studies to assess the implications of including non-health-related preferences for care processes, and location of services, in calculations of cost-effectiveness are required.

Study registration

This study is registered as PROSPERO CRD42016042570, CRD42016042573, CRD42016042574, CRD42016042576, CRD42016042575, CRD42014014850, CRD42015023877 and CRD42015024820.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 5. See the NIHR Journals Library website for further project information.

Registry-based randomised clinical trial: efficient evaluation of generic pharmacotherapies in the contemporary era

Randomised clinical trials are the gold standard for testing the effectiveness of clinical interventions. However, increasing complexity and associated costs may limit their application in the investigation of key cardiovascular knowledge gaps such as the re-evaluation of generic pharmacotherapies. The registry-based randomised clinical trial (RRCT) leverages data sampling from nationwide quality registries to facilitate high participant inclusion rates at comparably low costs and, therefore, may offer a mechanism by which such clinical questions may be answered. To date, a number of studies have been conducted using such trial designs, but uncritical use of the RRCT design may lead to erroneous conclusions. The current review provides insights into the strengths and weaknesses of the RRCT, as well as provides an exploratory example of how a trial may be designed to test the long-term effectiveness of beta blockers in patients with myocardial infarction who have preserved left ventricular systolic function.

The quality of denominator data in surgical site infection surveillance versus administrative data in Norway 2005-2010

Background

High quality of surveillance systems for surgical site infections (SSIs) is the key to their usefulness. The Norwegian Surveillance System for Antibiotic Consumption and Healthcare-Associated Infections (NOIS) was introduced by regulation in 2005, and is based largely on automated extraction of data from underlying systems in the hospitals.

Methods

This study investigates the quality of NOIS-SSI’s denominator data by evaluating completeness, representativeness and accuracy compared with de-identified administrative data for 2005–2010. Comparisons were made by region, hospital type and size, age and sex for 4 surgical procedures.

Results

The completeness of NOIS improved from 29.2 % in 2005 to 79.8 % in 2010. NOIS-SSI became representative over time for most procedures by hospital size and type, but not by region. It was representative by age and sex for all years and procedures. Accuracy was good for all years and procedures by all explanatory variables.

Conclusions

A flexible and incremental implementation strategy has encouraged the development of computer-based surveillance systems in the hospitals which gives good accuracy, but the same strategy has adversely affected the completeness and representativeness of the denominator data. For the purpose of evaluating risk factors and implementing prevention and precautionary measures in the individual hospitals, representativeness seems sufficient, but for benchmarking and/or public reporting it is not good enough.

Trends in Abdominal Aortic and Iliac Aneurysm Repairs in Norway from 2001 to 2013

OBJECTIVE/BACKGROUND

The objective was to examine trends in abdominal aortic and iliac aneurysm repairs in Norway from 2001 to 2013, and study regional variations and organizational developments in this type of vascular surgery.

METHODS

This was a retrospective study on aortic and iliac aneurysm repairs using data from the Norwegian Patient Register. The vascular centers were categorized by yearly volume of repairs into small (<18), medium (18-49) and large (≥50). Incidence rates were assessed per 100,000 ≥ 60 years. The percentage of endovascular aneurysm repairs (EVAR) was calculated among the conducted repairs at the three categories of centers and the South-Eastern, Western, Central, and Northern Norway Regional Health Authority (NRHA).

RESULTS

The national incidence rates of intact repairs per 100,000 ≥ 60 years increased from 57.4 to 65.7 (p < .01). Ruptured repairs decreased from 19.7 to 9.2 (p < .01). The rate of EVAR increased from 6.0 to 29.9 (p < .01) in intact and from 0.4 to 2.5 (p < .01) in ruptured repairs. The vascular centers were reduced from 25 to 16. The rate of EVAR was 27.1% (p < .01) higher at large centers and 7.9% (p < .03) higher at medium centers compared with small centers, and from 11.1% to 15.7% higher (p < .01) at the Central, Western, and Northern NRHA compared with the South-Eastern NRHA, which had the most centers (also in the large category). The national increase in intact EVAR from 10.6% to 43.3% was less compared with many other Western countries.

CONCLUSION

During the study period the rates of intact repairs increased while the ruptured repairs decreased. EVAR was associated with centers performing high volumes of abdominal aortic and iliac aneurysm repairs and regional authorities organized with few centers.

Registration in the Danish Regional Nonmelanoma Skin Cancer Dermatology Database: completeness of registration and accuracy of key variables

OBJECTIVE

To validate a clinical database for nonmelanoma skin cancer (NMSC) with the aim of monitoring and predicting the prognosis of NMSC treated by dermatologists in clinics in the central and north Denmark regions.

METHODS

We assessed the completeness of registration of patients and follow-up visits, and positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity of registrations in the database. We used the Danish Pathology Registry (DPR) (n = 288) and a review of randomly selected medical records (n = 67) from two clinics as gold standards.

RESULTS

The completeness of registration of patients was 62% and 76% with DPR and medical record review as gold standards, respectively. The completeness of registration of 1st and 2nd follow up visits was 85% and 69%, respectively. The PPV and NPV ranged from 85% to 99%, and the sensitivity and specificity from 67% to 100%.

CONCLUSION

Overall, the accuracy of variables registered in the NMSC database was satisfactory but completeness of patient registration and follow-up visits were modest. The NMSC database is a potentially valuable tool for monitoring and facilitating improvement of NMSC treatment in dermatology clinics. However, there is still room for improvement of registration of both patients and their follow-up visits.

External validation of the Swedvasc registry: a first-time individual cross-matching with the unique personal identity number

OBJECTIVE

To study external validity of the Swedvasc registry concerning numbers of procedures and mortality.

MATERIALS AND METHODS

Vascular registry data for carotid, infrainguinal bypass and aortic aneurysm (AAA) procedures were compared to the Swedish Hospital Discharge Register (SHDR) data, and the National Population Registry (for mortality) by matching every individual patient using the unique personal identity numbers (PINs). The time-period studied was 2000-2004 (5 years) for carotid and infrainguinal procedures. A separate analysis was performed for AAA-surgery in 2006.

RESULTS

The external validity for carotid, infrainguinal bypass and AAA repair was 93.4%, 93.0% and 93.1%, respectively. The 30-day mortality was 0.86% after carotid and 2.9% after infrainguinal bypass procedures. Mortality was 2.6% after planned and 25.9% after unplanned AAA repair. Although there was a general trend towards inferior outcomes after procedures not registered in the Swedvasc, those procedures were so few that in none of the analyses did the inclusion of non-registered procedures affect general outcomes significantly. Combining data from both registries, the incidence for carotid, infrainguinal bypass and AAA procedures was 7.8, 15.2 and 13.6 per 100,000 person-years, respectively. In the hospital-specific analysis for 2006 it was shown that the non-registered procedures for AAA were localized to one non-compliant county hospital, and small district hospitals not performing elective AAA-surgery but only rare emergency operations.

CONCLUSION

The external and internal validity of the Swedvasc registry allows to confidently assess volumes of, and mortality after, vascular surgery in Sweden.

Infrarenal Abdominal Aortic Aneurysm Repair: Time-trends during a 20-year Period

BACKGROUND

The goal of the present study was to investigate the number of operations for abdominal aortic aneurysm (AAA) including time-trends in treatment during a 20-year period. Operating time and anesthesia time were also studied.

METHOD

During the period 1983-2002, a total of 1,041 patients with AAA were treated with open surgery (905) or EVAR (136). Number of operations, type of graft, anesthesia time, and operating time were the variables investigated. Data were collected retrospectively from the patients' medical records.

RESULTS

There was an increase in the number of operations both for ruptured and non-ruptured AAA in men during the study period. Among women, an increase was observed only for ruptured aneurysm. Operating time and anesthesia time increased significantly during the 20-year period. The number of patients treated by EVAR increased significantly, beginning in 1995.

CONCLUSIONS

In conclusion, there has been an increase in the number of AAA operations, and the proportion of patients treated with EVAR is increasing. Furthermore, we found an increase in both anesthesia time and operating time. These trends may be important for allocation of resources needed for the treatment of patients with AAA.

Elective surgery for aortic abdominal aneurysm: comparison of English outcomes with those elsewhere

INTRODUCTION

The aim of this study was to quantify mortality after elective repair of abdominal aortic aneurysm (AAA) in England, and to compare English case fatality rates (CFRs) with those reported in the literature.

PATIENTS AND METHODS

English Hospital Episode Statistics (HES) for the financial years 1998/9 to 2001/2, linked to death data, were analysed. A systematic literature search was undertaken to identify studies reporting CFRs after elective AAA surgery. The CFR in England was compared with these studies by using confidence intervals on the CFRs and funnel plot techniques.

RESULTS

In the English study, elective repair of AAA was performed on 11,338 patients of whom 771 died within 30 days after surgery (6.8%). The literature search found 66 studies: 34 reported mortality rates that were within the 99% confidence limits of the English rates, 31 below, and one study above.

DISCUSSION

The CFR after elective surgical repair in England within 30 days of operation (6.8%) was higher than expected from the literature. Differences between England and other countries in quality of care is one possible explanation for the findings, but other explanations are possible and are discussed.

Data Quality of Surgery for Carotid Artery Stenosis. Are the National Vascular Registries Reliable?

OBJECTIVES

To study completeness of reporting carotid endarterectomies, including peri-operative stroke and mortality rate, in a national vascular registry, NorKar, and a national administrative registry, The Norwegian Patient Register (NPR).

DESIGN

Comparative registry-based national study.

MATERIALS

Member hospitals of NorKar, including 89% of carotid endarterectomies in Norway, were compared with relevant data in NPR for the years 2000-2002.

METHODS

We compared procedure-codes, diagnosis-codes, in-hospital death and the occurrence of peri-operative stroke after treatment for carotid artery stenosis in the two registries to evaluate completeness.

RESULTS

Compared with the NPR numbers, 16% of carotid endarterectomies were missing in the reports from member hospitals of NorKar. Further, during this three-year period, there was an under-reporting of seven strokes and two deaths. The discrepancy was most pronounced in 2001.

CONCLUSIONS

There is an under-reporting of patients operated on for carotid artery stenosis in NorKar according to NPR numbers as well as an under-reporting of early deaths and strokes. There is a need for better quality data in the NorKar Registry. Registry quality would be likely to improve if patient identifiable data were available in both registries.