The UK NHS AAA screening programme was started in 2009. Screening is carried out according to the pathway described in Figure 1. Considering medical practice and diagnostic criteria in Europe, it is likely that the screening pathway would be similar in other European countries if AAA screening were implemented.

Figure 1. Abdominal aortic aneurysm screening pathway in UK {1}

NHS guidelines for AAA screening {2} have identified 65-year-old men as the target population for AAA screening based on clinical studies. In the UK all men who are registered with a general practitioner (GP) will receive a personal invitation by mail for screening in the year that they turn 65. Men older than 65 can self-refer into the programme. Invitations are sent and feedback collected by local screening centres. Men who do not attend their screening invitation are either sent a second appointment or asked to contact their local programme to arrange a new date. Men who are invited a second time are sent a further letter saying they will not be invited for further appointments but can contact their local screening programme to self-refer for screening {2}.

Clinic locations are decided locally to ensure that they are accessible. Scanning typically takes place within community healthcare facilities such as community clinics, community hospitals, mobile units and primary care facilities. Men are seen by a health professional (sonographer or screening technician) on arrival at the clinic so that they can receive further information about screening before deciding whether to participate. Men are asked to give their consent to the screening procedure and the use of their personal information. Screeners record two anteroposterior (AP) measurements in centimetres of the maximum abdominal aortic diameter. Results are communicated immediately to all men verbally. Written results are also sent to GPs. Further investigations and treatment depend on the results of the scan:

• Normal result: the aorta has a diameter of less than 3 cm. No aneurysm has been detected. The man is informed of his result and does not require any further scans
• Small aneurysm: the aorta is slightly enlarged and has a diameter of between 3 and 5.4 cm. Men with a small aneurysm do not need to have treatment but are invited to have follow-up scans to monitor the size of the aneurysm.
• If the aorta is between 3 and 4.4cm a follow-up scan is offered in a year
• If the aorta is between 4.5 and 5.4cm a follow-up scan is offered in 3 months

In addition to follow-up scans, men are offered advice on how to reduce their cardiovascular risk factors. The man's GP may also be informed of the need to review medication and reassess blood pressure monitoring,

• Large aneurysm: the aorta has a diameter of over 5.5 cm. Men with a large aneurysm are referred to a consultant vascular surgeon to discuss treatment. Because of screening, surgeons need to be prepared for more elective surgery. A minimum of 20 operations per unit per year is defined as the quality standard. Alternative treatment is endovascular aneurysm repair (EVAR) {2}.

If the aorta cannot be visualised at the clinic a further scan appointment is arranged. If it cannot be visualised at the second appointment then the man is invited for a further scan at a hospital medical imaging unit. He is given guidance recommending minimum food and drink intake in the 4-h period before the proposed scan. Letters are also sent to GPs informing them of non-visualised screening results {2}.

The most significant impact of the screening programme will be on vascular surgery services and theatres. The number of elective operations will increase but there will be a decrease in the number of emergency operations over time {3}. A meta-analysis of four randomised controlled trials of screening older men for AAA was carried out by Lindholt and Norman (2008).  A significant reduction in emergency operations (odds ratio=0.55; 95% confidence interval (CI) 0.39-0.76) and an increase in elective operations (odds ratio=3.27; 95% CI 2.14-5.00) was found {4}.

As systematic population-based AAA screening has not been implemented in most European countries, the possible change after introducing the screening, can be estimated based on the number of elective and emergency operations at present. Mani et al. (2011) have analysed the statistics of AAA repair in several European countries. Table 1 shows the numbers of elective and emergency operations for Denmark, Norway and Sweden.

Table 1. Elective and emergency AAA operations in three European countries {5}

As a result of the increasing number of elective and the decreasing number of emergency operations after the introduction of AAA screening, the workload in involved hospital departments changes. According to The Scottish Government Health Improvement Strategy Division, patients who survive emergency repair of a ruptured AAA are admitted to the intensive treatment unit (ITU) and prolonged ITU admissions are common. After elective open AAA repair most patients in Scotland are admitted to the high dependency unit (HDU) rather than the ITU. After EVAR repair most patients are admitted to an HDU for one day but in some hospitals in Scotland patients are admitted to the vascular surgery ward after the procedure and do not occupy critical care beds {3}.

AAA screening is different from other screening programmes in that the mortality rates associated with treatment are significant: 3-5% for open surgery and 1-3% for EVAR {3}.

Therefore actual mortality is very dependent on the percentage of men that are treated with EVAR repairs. Also other risk factors like age and sex influence mortality. More detailed information about the percentage of EVAR procedures and the percentage of procedures done in women for Denmark, Norway and Sweden are presented in Table 2.

Table 2. Mean age, % of procedures in women and% of EVAR procedures for elective and emergency operations in three European countries (95% CI) {5}

The Vascular Society of Great Britain and Ireland has issued a framework for improving the results of elective AAA repair. The aim of the framework is to halve the mortality rate for elective AAA surgery in the UK (to 3.5%) by 2014 {6}.

Preoperative:

• All patients should undergo standard preoperative assessment and risk scoring to determine their suitability for EVAR.
• Each hospital should have defined pathways for the correction of significant medical risks (cardiology/renal/respiratory) before intervention.
• All patients should be seen by an anaesthetist for reviewing and optimising medication.
• All elective procedures should be reviewed preoperatively by surgeon(s) and radiologist(s) as a team. Ideally, a vascular anaesthetist should also be involved to consider fitness issues that may affect whether open repair or EVAR is offered.

{6}.

Operation:

• Interventions should be undertaken (or supervised) by a consultant surgeon/radiologist/anaesthetist with training and expertise in elective vascular procedures and a routine clinical practice in this specialty.
• Open AAA repair should include the following components: normothermia, cell salvage, rapid infuser, easy access to blood products (within 1 hour) and availability of haemostatic agents including glue.
• EVAR should only be undertaken in a sterile environment of theatre standard, with optimal imaging facilities. A range of rescue stents and devices should be immediately available, together with the expertise to deploy them {6}.

Facilities:

Elective AAA repair should only be undertaken in hospitals where:

• There is a 24/7 on-site vascular on-call rota for vascular emergencies of 1:6 or greater, covered by consultant vascular surgeons and interventional radiologists, to ensure adequate post-operative care.
• There is a 24/7 critical care facility with the capacity to undertake mechanical ventilation and renal support, and with 24-hour on-site anaesthetic cover.
• Wards for dedicated vascular patients should be available with the provision for single sex cubicles or bays.
• At least one endovascular theatre or theatre specification interventional radiology suite is required, preferably with a fixed C arm and a dedicated X-ray table.
• A minimum number of AAA procedures are undertaken. It is recommended that hospitals undertaking fewer than 33 elective AAA interventions per year (100 over 3 years) should not continue to offer these procedures.
• Hospitals should know their AAA mortality and should seek to validate both national audit and Trust data. They should be able to demonstrate safe practice.
• Units with mortality rates for elective repair of 6% or greater should seek external professional review of their care processes.
• An on-site vascular laboratory should be available {6}.

Also the Scottish AAA screening programme foresees a minimum of 20 elective surgeries per unit per year, rising over time to an estimated 32. Patients found to have an AAA should be referred to services that can undertake both open and endovascular repair of aneurysm and that offer advice to each patient on which procedure is most appropriate {3}. All referrals must be assessed for suitability for EVAR. It is estimated that 50% of screen-detected aneurysms in Scotland will be suitable for endovascular repair {3}.

There may be a small impact on Primary Care services from men requesting further information on the screening programme. Information on the screening programme will be circulated to Primary Care prior to roll out. GP practices will be notified of patients who are on surveillance or referred to vascular services {3}.

The difference in patients’ paths is that more men are referred for treatment before AAA rupture (which would send them directly to emergency departments).

UK recommendations for AAA screening organisation {2} were used to describe quality assurance (QA) aspects of systematic population-based AAA screening.

QA systems support commissioners and providers in clinical governance so that core processes are safe and the programme achieves better outcomes. Several activities are involved, including:

• accredited training programmes and continuing professional development of staff
• regular appraisal and refresher training
• standardised calibration of equipment
• monitoring of standardised outcome and performance information with feedback of comparative information to local services from national analysis of screening data, AAA surgery and AAA deaths
• site visits for peer review
• supporting activities for avoidance and management of serious incidents

Ultrasound equipment

• range of standard commercial phantom test objects used, with tests undertaken by an independent Registered Clinical Scientist (Medical Physics)
• periodic testing
• as per acceptance tests, using the same test objects and undertaken by the similarly qualified staff and results reported to the screening office Carried out on an annual basis
• regular testing
• QA checks done at routine maintenance service by equipment manufacturer, carried out at service intervals detailed by the manufacturer
• routine monthly tests using a standard test object carried out locally by the senior sonographer and results reported to the screening office

Other

• questionnaires sent periodically to a sample of randomly selected service users (doctors, practice managers/staff, patients, vascular surgeons) to ask whether any problems arose as a result or in connection with the screening programme
• enquire about any procedural changes that could improve the delivery of the screening programme
• monitor time from referral to outpatient consultation
• referral to vascular unit
• monitor time from referral to surgery {2}

Several strategies to make a screening programme easily accessible are used. The most widely used strategy is to consider the size of the population and the patients’ geographic distribution and to establish local screening centres for better availability. Also mobile screening vans can be used for more distant areas.

UK recommendations for AAA screening organisation {2} were used to give an example of the human resources needed, and their workloads, responsibilities and training needs for systematic population-based AAA screening.

Clinical staff

Director/Clinical Lead (0.2 Whole Time Equivalent (WTE)* per 800,000 population)

A vascular surgeon, responsible to the National Programme Centre, will have responsibility for the overall running of the local programme and for clinical support for their Programme Coordinator, particularly in matters involving patient care. They will also be responsible for making clinical decisions related to screening patients up to the point where a referral has been made.

The primary purpose of this role is to act as the strategic lead for the local AAA screening programme. The Director will oversee the screening programme and take clinical responsibility. The role of the Director is to ensure the successful implementation of the programme and that a high quality service is maintained following implementation.

Lead ultrasound clinician (0.1 wte per 800,000 population)

A radiologist/consultant sonographer/vascular scientist will have special responsibility for quality assurance of staff and the screening process, and responsibility for the screening equipment, staff accreditation and monitoring of clinical performance (including review of scans from screening clinics). This task is often delegated to the clinical skills trainer but this is a local decision. Any quality assurance concerns should be brought to the attention of the director. They will advise on which ultrasound equipment should be purchased and when it needs to be updated or replaced.

Consultants in the vascular units

Vascular surgeons are not employed by the screening programme and are unlikely to participate in the screening programme as such.

In hospital vascular units, the consultant responsible for the care of the patient will be classed as the “responsible” doctor once the referral is received. They should:

• On referral from the local AAA screening programme, ensure that further confirmatory diagnostic image testing is performed and keep records of the findings of this testing
• Assess patients with a view to surgery
• Notify the coordinator of the local screening programme of the outcome of the initial and further outpatient visits and, if indicated, the treatment
• Submit data for audit purposes on an ongoing basis of all AAA surgery.

Screening staff

Clinical skills trainer (senior sonographer/vascular scientist – 0.1 wte per 800,000)

A senior sonographer/vascular scientist is responsible to the director/clinician lead. As the first-line supervisor of the screening technicians, the Clinical Skills Trainer is responsible for staff training and regular review of staff for quality assurance in addition to undertaking routine equipment quality assurance assessments and ensuring regular maintenance of the ultrasound equipment. CSTs also run occasional AAA screening clinics to maintain their skills. They should have extensive experience of training in the workplace. The work within these clinics will include:

• Ensuring that men attending clinics are booked in smoothly and efficiently and are aware of the benefits and risks of the AAA screening programme and give informed consent to the procedures
• Accurately recording aortic sonographic measurements
• Collecting other patient information
• Reporting scan results and their implications to patients both verbally and in writing
• Preparing copies of the results for GPs
• Transferring clinic data to the screening office
• Updating the screening management information technology  (IT) system

As with other clinical staff, more time may be required during initial set-up.

Screening technicians (3 wte per 800,000)

Screening technicians ensure that men attending clinics are booked in smoothly and efficiently and are aware of the benefits and risks of the AAA screening programme and give informed consent to the procedures. They will accurately record sonographic measurements of the aortic diameter, collect other patient information and report scan results and their implications to patients both verbally and in writing. They will also prepare copies of the results for GPs, transfer clinic data to the screening office and update the screening management IT system.

There will be a requirement for all those undertaking the scanning to have attended the nationally approved and accredited training course and fulfilled all the competency requirements of the training. It is recommended that all newly appointed screening technicians have an initial probationary period built into their contract to allow time for training and assessment of competency.

The CST is the first line supervisor of the screening technicians and in turn would be supported by the lead ultrasound clinician.

Nurse practitioner (0.1 wte per full capacity programme – 7,000 scans per year)

The nurse practitioner is involved in assessing and counselling men at specific points in the screening process and giving advice on changes in lifestyle as appropriate. Further referral on to other specialists should be made following discussion with the director of the local screening programme.

Management, administration and technical Staff

Coordinator (1 wte per 800,000 population)

The coordinator is responsible to the director/clinical lead, who delegates the task of the day-to-day running of the screening programme to the coordinator but remains the responsible clinician for patients entered into the screening programme. The primary purpose of the coordinator’s role is to direct the day-to-day operational management of the local programme. They oversee the work of the clerical officer and screening team.

Clerical officer (1 wte per 800,000 population)

The clerical officer is responsible for the administration and is the first point of contact between the screening population and the screening office. The work involves administering and processing patient invitations and appointments, recording information and updating data systems relating to results and patient outcomes and ordering supplies. The clerical officer plays a supporting role to the local AAA screening programme and ensures that members of the public are informed of the benefits of the programme.

Medical physicist (5 days per year for a full capacity programme – 7,000 scans per year)

The purpose of this role is to undertake acceptance of new ultrasound machines and to provide independent, regular quality assessments using sophisticated test objects. This specialist will undertake annual assessments on all the ultrasound machines and probes, assisted by the Senior Practitioner. They will prepare reports for the Director of the local programme.

IT lead

The IT lead supports the coordinator in the timely installation of IT equipment and software, in accordance with the IT checklist issued by the software supplier. The IT lead acts as a single site contact point for IT for the software supplier during implementation. The IT lead is responsible for ensuring the appropriate software for the programme is accessible and they will be available at a high level to troubleshoot when required. They will also facilitate the set-up and process for archiving screening data and back-up.

Governance

The provision of the AAA screening programme involves a number of organisations:

• Strategic Health Authorities
• Primary Care Trusts
• Primary care providers
• Local Screening Programme
• Diagnostic and Treatment Services {2}.
• Whole time equivalent is calculated by assessing the hours the employee is contracted to work and the standard hours for the position (generally 40 hours per week).

UK recommendations for AAA screening organisation {2} were used as an example of informational needs for systematic population-based AAA screening.

Men should be able to make a genuinely informed choice based on an understanding why they are attending for screening, the risks involved and associated with a positive result, and what happens to their records after they are screened {2}.

Implementing a screening programme will require three different kinds of information:

1) For publicity to inform the target population and their relevant others about the screening programme.

The national programme director will be responsible for publicity in relation to the programme and central written resources.

Nationally developed and approved information is available to all local AAA screening programmes. It is the responsibility of the local programme to ensure that information is available to all men and that literature is displayed in appropriate locations.

The invitation leaflet is designed to ensure that men are told what screening can and cannot achieve. This, along with the invitation letter, addresses the need to inform subjects about the use made of personal information for audit.

Posters are available and provided by the national programme centre for display in GP surgeries, other primary care facilities and other suitable public locations identified locally. Information sheets for GPs and other healthcare professionals are also available and provided by the national programme centre.

A website for patients and professionals is administered by the national programme centre {2}.

2) For men participating in the programme that do not need follow-up or operation; men needing follow-up; and men needing operation.

There should be separate leaflets for men who enter the surveillance programme and for those identified with an AAA of 5.5 cm or greater setting out the benefits and risks of AAA surgery. Informed consent must contain information about the risks, benefits and alternatives of treatment {2}. In an ultrasound study most surgeons agreed that mortality should be clearly stated to patients eligible for operation. There were substantial variations in opinion across surgeons regarding what risks should be included and which complication rates to quote {7}. It is agreed that numerical presentation of risks is most suitable for patients, depending on the patient’s preference for being more or less involved in the decision making process {8}.

3) For organisational aspects of screening programme (for staff).

The programme’s internal communication plan is specified in the job descriptions of staff (using IT solutions, mail, telephone, meetings) {2}.

Co-operation, outside the screening programme, needs to be arranged between screening programme staff and surgeons to whom patients with aneurysms larger than 5.5 cm are referred. It is ethically and medically important that all subjects have both a consultation with a surgeon and the surgery itself (when needed) within a reasonable time period. It is also crucial to evaluate the results of the screening programme – by analysing the number of elective procedures and the mortality of those screened and treated. All this needs a working co-operation between screening programme staff and surgeons {2}.

Decentralisation is preferred to make screening more attainable for relatively elderly people (men 65 years old). A Danish hospital-based cohort study of AAA screening showed that distance to screening facility is one of the attendance rate predictors {9}.

Ultrasound machines with digital recording devices are easily portable. Decentralised screening programme is not expected to decrease quality noticeably for several reasons: uniform training of staff, relatively simple and highly accurate diagnostics.

In both European countries, Sweden and the UK, where population-based systematic AAA screening has been implemented it is de-centralised.

Centralisation of treatment should be considered, because a minimum of 20 elective operations per unit per year are recommended to ensure the quality of the operation. This is important because open surgery is associated with a death risk of approximately 5%.

Answered in ORG5.

Revenue costs

Administration costs

One full time administrator is required per centre to organise the screening programme. A consultant vascular surgeon will be attached to each screening centre and will work there for one half day a week. Two central administrators will be required to organise the programme for the whole of England. Specific salaries of staff are country-specific {2}.

From the MASS trial costs of £1.50 for an invitation and £1.47 for a re-invitation are given; these cover clerical staff time, postage and stationery, cost of obtaining patient details, and office space and equipment {10}.

Screening and treatment costs

The number of devices and screening staff depends on the size of population that needs to be screened and other organisational aspects.

Each centre requires financial resources for maintenance of equipment – ultrasound machine, computer and blood pressure machine. Exact costs depend on the devices used (and whether they are mobile or not). The cost of training technicians is to be included. For quality assurance one radiologist per centre and one radiologist for national quality control are needed {2}.

Prices of medical procedures are country-specific.

Table 1. Prices of medical procedures in selected European countries {11}

Capital costs

Capital costs include ultrasound machines and computers, premises for administrative and diagnostic purposes or mobile screening unit (if used). It needs to be taken into account that capital needs to be renewed after fixed time period {2}.

There are also capital costs arising from providing extra beds and intensive care unit beds for post-operative patients.

Every country needs to assess their costs independently using cost-effectiveness analyses or other economic evaluation methods. It is important to take into account that all costs are likely to increase from year to year. Also demographic changes influence all estimates.

Screening programmes are usually financed directly by national or local government. Some countries also apply cost-sharing so that the person to be screened pays part of screening costs (in Sweden men pay a fee for initial ultrasound examination) {11}.

Search in MEDLINE, 11 April 2012, by Kristi Liiv (UTA).

Search terms: screening (abstract), budget impact (all text).

38 hits. 0 about AAA screening. Similarly, no budget impact analyses were found by the ECO domain in cost-effectiveness articles.

One article (Canadian health technology assessment) was found by running the Google search engine with the search phrase “AAA screening impact on healthcare budget”.

Reference: Thanos J, Rebeira M, Shragge W, et al. Vascular Ultrasound Screening for Asymptomatic Abdominal Aortic Aneurysm. Health Policy 2008;4(2):75–83.

Not found.

According to the UK recommendations for AAA screening organisation {2} the most critical points in management are:

• ensure that all eligible men are invited and well informed about the risks and benefits
• ensure that all men needing follow-up or treatment get what they need without delay
• information between screening programme management, GPs, surgeons and patients is moving accurately and without delay
• all information about patient (procedures, treatment result) is saved and available for programme evaluation {2}

IT is used for all monitoring processes.

Systematic screening requires call and recall information and the capture and management of ultrasound images. In the UK the software solution Screening Management and Referral Tracking (SMaRT) system is used.

The software system should have following functions:

• identification and collation of screening cohort
• management of administration, screening and referral process
• recording of AAA surgery and outcomes {2}

A national screening programme gives criteria based on risk information about who should receive screening invitations.

The most important and widely used criterion is age. Abdominal aortic aneurysms (AAAs) are uncommon in people under the age of 60 {12}. In the UK 65-year-old men are invited (because of their elevated risk of AAA rupture). Older men can come for screening by self-referral. Information about the men and their age can be obtained from any national database (population register, GP lists, health insurance database) {2}.

In the UK individuals are excluded from the programme if:

• they have previously been diagnosed with an AAA
• they have previously undergone surgery for AAA repair
• on advice from their GP related to other health concerns
• they have requested that they are permanently removed from the AAA screening programme
• they have already had a scan through the AAA screening programme and the aorta was within normal limits
• they have made an informed choice that they do not wish to be invited for screening {2}

In the UK men and women of any age with a strong family history can be scanned under existing procedures following referral by their GP to a medical imaging department {2}.

In Lithuania 65-year-old men with high blood pressure identified during a doctor’s visit are offered the possibility of screening although this is generally defined as opportunistic not systematic population-based screening. In Sweden 65-year- old men are invited and screening of siblings is not included but vascular surgeons inform patients with AAA that siblings over 50 years old should undergo ultrasound evaluation for possible AAA {11}.

No direct evidence exists of complete acceptability to health professionals and the public but acceptance is high and the introduction of screening in the UK would be supported by the majority of vascular surgeons, provided that sufficient resources were made available to carry out screening effectively and efficiently. In addition questionnaires asking about acceptability were sent to participants and GPs. The majority of responses were positive {13}.

In the MASS trial no significant changes in quality of life were detected throughout the screening process. In addition, questionnaires asking about acceptability were sent to participants and GPs. The majority of responses were positive {13}.

In Sweden the attendance rate for screening is 80-85% of those invited {11}.

A Danish cohort study showed an attendance rate of 76% after postal invitation to AAA screening {9}.

No answer found.