PHAST is an observational cross-sectional multicentre feasibility study, funded by the NIHR Programme Grants for Applied Research scheme (NIHR200601).

Research question: Can cardiovascular health be improved by adding screening for peripheral arterial disease (PAD) and high blood pressure (BP) to the NHS abdominal aortic aneurysm (AAA) screening programmes?

Background: Cardiovascular (CV) disease is the leading cause of death in England. PAD and/or high BP affect between 30-40% of men aged 65. A third of these men do not know they have these diseases. Interventions to reduce CV risk are recommended by the National Institute for Health and Care Excellence (NICE) for individuals with PAD or high BP. The NHS AAA screening programmes are well attended (78% uptake). This infrastructure represents an opportunity to screen for other CV diseases with minimal additional effort/cost.

Aims and objectives: To provide evidence for the UK National Screening Committee to make a recommendation for or against screening men for PAD and high BP at the same time as screening for AAA. Our hypothesis is that screening men for PAD, high BP and AAA will improve health, is acceptable and is cost effective. This evidence will be generated through the following 3 objectives:

1: Identify an accurate screening test for PAD and high BP that is suitable for use in the NHS AAA screening programmes.

2: Determine the acceptability, uptake and response of men to combined screening.

3: Conduct a cluster cross-over trial of combined PAD, high BP and AAA screening vs AAA screening alone.

Methods:

1: A systematic review of devices/methods for PAD/high BP screening. The acceptability and practical utility of each device/method will be established in conjunction with AAA screening staff. Accuracy and utility will be considered in a consensus exercise to select the best methods/devices for PAD and/or high BP screening.

2: Feasibility study of PAD+BP+AAA screening. Uptake and disease prevalence will be quantified in men invited for screening. A qualitative study will assess screening acceptability and responses to screening outcomes. Clinical follow up will examine uptake and adherence to CV risk management, and quality of life. Women will be included to generate pilot data for a trial for women.

3: A cluster cross-over trial will be conducted in the NHS AAA screening programmes. Over two screening years, AAA screening units will deliver one year of PAD+BP+AAA screening and one year of AAA screening in randomised order (primary outcome: major adverse CV events; data collection by record linkage; 3 year follow-up). Data from the trial and feasibility study will be used for economic modelling.

Timelines:

Programme duration: 99 months

Screening test selection: months 1-6.

Feasibility study: Recruitment and qualitative study: months 7-30; follow-up: months 30-90.

Effectiveness trial: Approvals/staff training: months 1-27; trial recruitment: months 28-52; follow-up months 53-89.

Analysis/dissemination: months 90-99.

Impact and dissemination: This programme will lead to improved cardiovascular health for the public, and reduced acute care burden and costs for the NHS. The results of this research will be disseminated by conventional and social media, and scientific publications and presentations. An evidence review will be submitted to the National Screening Committee.

Participating centres:

University Hospitals of Leicester NHS Trust

Cambridge University Hospitals NHS Foundation Trust

University Hospitals Coventry and Warwickshire NHS Trust

NHS Greater Glasgow and Clyde