The question we will be answering: is screening for AF effective and cost effective in reducing stroke and other key outcomes compared to current practice?
To do this we are breaking the programme of work down into the following main areas:
Feasibility study 1 – complete
We have conducted a feasibility study in 10 GP practices in the East of England. This has confirmed it is feasible to deliver an AF screening programme in general practice, and that high numbers of patients accept an offer of AF screening and go on to complete the screening process. This enabled us to finalise the design of the cluster randomised controlled trial in light of our findings.
The feasibility study 1 is registered with the ISRCTN.
Feasibility study 2 (screening at home) – complete
We were about to start the cluster randomised controlled trial in March 2020 when the COVID-19 pandemic struck. It was clear that we could not at that time continue with screening delivered in the practice. We therefore added a second feasibility study to test screening at home. Working with 3 GP practices in the East of England we tested a number of different approaches to delivering the AF screening intervention, to see if any of these approaches can be used for the subsequent trial.
Cluster randomised controlled trial – now recruiting
We will carry out an experiment in 360 general practices across England involving 126,000 patients in which 120 practices undertake screening and 240 do not (controls). Screening will be done at home. We will follow up people for five years without having any further direct contact with them. We will see if screening leads to fewer strokes, heart attacks, and deaths, and whether it increases risk of serious bleeding (the main harm associated with anticoagulants).
We have just started the trial in 36 practices (12 screening and 24 control), who will recruit 12,600 patients. This is an internal pilot trial. This will help us to decide if:
- the screening programme needs refinement;
- screening is identifying the number of new cases of AF that we expected;
- sufficient numbers of newly identified people with AF are started on blood thinning (anticoagulation) therapy;
- screening causes any undue worry in people.
We will then roll the trial out to the remaining 324 practices across England.
We will carry out case studies in practices taking part in screening to clarify how to carry out screening, both in the randomised controlled trial, and in a potential national screening programme. These studies will involve observing what goes on in practices when carrying out screening, and interviewing staff and patients. We particularly want to explore:
- issues around consent to screening;
- sharing decision making about treatment if AF is found;
- factors associated with uptake of screening;
- patient concerns.
Some participants will be sent health questionnaires to complete at various stages in the trial.
Cost effectiveness analysis
We will determine if screening does lead to fewer strokes, and whether this is good use of NHS resources.
The trial is registered with the ISRCTN.