Title: Peripheral arterial disease, High blood pressure and Aneurysm Screening Trial (PHAST) – An evaluation of the acceptability, effectiveness and cost effectiveness of screening for peripheral arterial disease and high blood pressure at the same time as abdominal aortic aneurysm.
Funder: Department of Health and Social Care

Abstract: 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.

Lay abstract: The problem: The main blood vessels in the legs, the arteries, can become narrowed or furred up by fatty deposits. This is called peripheral arterial disease (PAD). People with PAD, and people with high blood pressure (BP) are more likely to develop heart disease and other circulatory problems (cardiovascular disease). One third of people aged over 65 who have PAD and/or high BP are not aware of it. If detected early, doctors can help people with PAD or high BP reduce their risk of developing cardiovascular diseases. The opportunity: At the age of 65 men are invited for an ultrasound scan to check for a condition called abdominal aortic aneurysm (AAA screening). Eight out of ten men attend for AAA screening. This would be a good opportunity to check them for PAD and high BP as well. Aim: To find out if screening for PAD and high BP at the same time as screening for AAA reduces the risk of cardiovascular disease. Methods: Working with NHS AAA screening staff, we will identify the best way to screen for PAD and high BP. The new screening tests will be road-tested in 3 screening units. Men will be interviewed to find out what they think of the new screening, and how their screening results might change their behaviour. Women will be included in this stage of the research to find out if they might also benefit from PAD and BP screening. After our road-testing stage, PAD and BP screening will be introduced for one year at a time in AAA screening units. Men who are found to have PAD or high BP will be asked to make an appointment with their GP. Their GP will assess their risk of heart and circulatory diseases, and offer advice and treatment to reduce this risk if necessary. We will use NHS records to see if men who are offered PAD/BP screening are less likely to develop problems with their heart or circulation than those who are not offered screening. Public involvement: Men who have been through the AAA screening process have helped us design this research. These men and other members of the public will help us to run the research and communicate the results effectively. Sharing our findings: The results of this research will be made available to the public and to researchers. Our team has good links with UK public health bodies that will ensure the results of this research are acted upon. Impact: Every year, adding PAD and BP screening to the AAA screening programme could help around 11,000 men reduce their risk of suffering from heart disease and other circulatory diseases.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES;4.4 POPULATION SCREENING
Health categories: CARDIOVASCULAR