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The MESI system ranks highest in a study for the UK NHS AAA

It is now a preferred candidate for a broader PAD population screening program

The MESI system has been examined in a systematic review of the automated and semi-automated ABI or TBI-measuring devices available in the UK in terms of usability for a PAD screening program. The devices were compared on the basis of a systematic literature review (diagnostic accuracy, sensitivity, and specificity), a clinical evaluation of UK NHS AAA screening providers (set-up, portability, ease of use, speed), and a consensus conference. The MESI system ranked highest in most of the categories and was selected as a preferred candidate to be used in a PAD population screening program.

In this blog you will learn:

The background of the systematic review (Selecting Portable Ankle/Toe Brachial Pressure Index Systems for a Peripheral Arterial Disease Population Screening Programme: a Systematic Review, Clinical Evaluation Exercise, and Consensus Process)

Cardiovascular disease (CVD) is the most frequent cause of death in England and accounts for one-third of all deaths. [1]

In England, men after 65 can participate in NHS AAA (National Health Service – Abdominal Aortic Aneurism) screenings provided locally in the form of Doppler ultrasound. The attendance level is quite good – up to 80%. Men under 65 and women are not included in this screening as the risk of abdominal aortic aneurism is much lower in these age groups [2].

The European Society for Cardiology (ESC) and the National Institute for Health and Care Excellence (NICE) guidelines recommend that PAD presence is assessed by measuring the Ankle-Brachial Index (ABI). Since such big numbers of men are seen in the scope of the NHS AAA programme, adding an ABI screening for PAD would be a good solution for early prevention.

The advantages of automated ABI screening compared to the gold standard – Doppler, is that the latter takes quite a lot of time. It also requires specialised training as it may otherwise lead to poor accuracy and undertreatment.

A study was devised to determine the most appropriate ABI or TBI system to be used in a community PAD screening programme. The MESI system ranked highest in most categories, and was selected as a good candidate for such screening.

The form of the systematic review (Selecting Portable Ankle/Toe Brachial Pressure Index Systems for a Peripheral Arterial Disease Population Screening Programme: a Systematic Review, Clinical Evaluation Exercise, and Consensus Process)

The systematic review is part of the “Peripheral arterial disease, High blood pressure and Aneurysm Screening Trial” (PHAST) study as the first step of a larger programme supported by the National Institute of Health and Care Research. The aim was to identify the ABI/TBI system most suitable to include PAD screening into AAA screening. The system selected will be used in the next part of the PHAST research on the feasibility of community PAD screening. (As AAA screening only covers men, it needs to be noted that a pilot PAD screening programme for women is also being implemented and evaluated as a part of the PHAST research.)

The systematic review authors come from the University of Leicester, the University Hospitals of Leicester NHS Trust, the National Institute for Health Research (NIHR) and the Leicester Biomedical Research Centre. The review compared 6 different automated or semi-automated ABI/TBI systems. The initial conditions for inclusion were availability in the UK, easy portability (lightweight, fitting into 1 bag), affordability (less than £5,000) and CE marking.

The examination of the systems was conducted in several stages. The first one was a systematic literature review on the diagnostic accuracy, sensitivity and specificity of the aforementioned ABI/TBI systems compared to the gold standard.

The second stage was a clinical evaluation of these systems by 39 AAA screening staff members with an average of 6.5 years’ experience in the screening programme. The systems were tested on live volunteers and graded by means of a questionnaire on their convenience (portability, practical use and data interpretation).

The third stage was a conference of AAA screening staff members, AAA screening managers and PHAST investigators with the aim of a group consensus as to which system was most suitable for PAD community screening. This took place in the form of a vote, where the 6 systems were ranked from best to worst.

The findings of the systematic review (Selecting Portable Ankle/Toe Brachial Pressure Index Systems for a Peripheral Arterial Disease Population Screening Programme: a Systematic Review, Clinical Evaluation Exercise, and Consensus Process)

The findings presented in the Discussion part were the following:

It was concluded that the MESI would be the best candidate as it scored high for accuracy within the systematic review, and also for usability, comprehension of results, and setup and portability in the clinical evaluation sessions. Screeners commented that it was easy to transport …, and it was the quickest and easiest test to perform.

The aim of the review was to select an automated ABI or TBI device to use in the future feasibility study on including PAD screening into the existing AAA screening services. The MESI system won the highest overall score, so it will be used to find how the additional PAD screening service affects the attendance rates. The final part of the research will be a randomised controlled trial assessing the impact of PAD screening on cardiovascular health.