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Clinical Effectiveness Group

Optimising medications to prevent stroke

A woman having her blood pressure taken by a GPThe challenge

Atrial fibrillation (AF) is a heart condition that causes an irregular heartbeat and blood clots. It is responsible for 1 in 5 strokes.

Anticoagulant medication reduces the risk of stroke in people with AF by more than half, but many patients are not yet prescribed them. In 2016, of the 17,000 people with AF in North East London, about 1,500 should have been on anticoagulants but were not – if they were all anticoagulated it would prevent 100 strokes over five years. The picture was similar nationally.

The information needed to identify who should be anticoagulated exists in the electronic health records held by GPs. But the only way to see this information, previously, was to open tens of thousands of patient records individually.

What we did

We developed a quality improvement programme that increased anticoagulation and reduced other risk factors for stroke. Firstly, we built a data-driven search tool called the ‘Active Patient Link for Atrial Fibrillation’ (or ‘APL-AF’). Using the tool, a GP or pharmacist can search their entire practice register in minutes to see a list of their patients with atrial fibrillation, and rapidly view whether they are taking an anticoagulant or not.

In each patient, different factors influence the best treatment options. Without leaving the tool, the GP or pharmacist can ‘virtually review’ all relevant factors about an individual, including their blood pressure, other health conditions and other medications, including statins. This information is used to call patients for a face-to-face consultation to start anticoagulation.

Across North East London, we worked with local NHS Clinical Commissioning Groups (CCGs) to educate practices, engage pharmacists, set up multi-disciplinary meetings to consult on complex cases, and establish financial incentives to support and encourage the professionals using our APL-AF tool.

Local success

We initially implemented APL-AF in Redbridge CCG in east London in 2016, then in the bottom 10% in England for anticoagulation. The proportion of eligible people taking anticoagulants increased from 77.0% to 83.3% in the first year - an increase of 290 people. We estimate that in those 290 people, anticoagulation and medicine optimisation will prevent 30 strokes over five years.

London and beyond

In 2017, we implemented the APL-AF tool across the whole of North East London. A year later, North East London became the highest performing Sustainability and Transformation Partnership (STP) in London for anticoagulation. City & Hackney became best CCG in London, and fourth in England.

In 2019, we collaborated with UCL Partners to implement APL-AF and the improvement programme across North Central London. A year later, North Central London was the most improved STP in England for anticoagulation. In the first year, an additional 1,742 patients were anticoagulated. We estimate that will prevent 170 strokes over five years.

The APL-AF tool and related resources are available nationally, for free. Find out more here.


Clinical Lead: John Robson. In collaboration with Jagjot Kaur Chahal, Sotiris Antoniou, Mark Earley, Shabana Ali, Khalid Saja, Harjit Singh and Peter K MacCallum.

Published research: Preventing strokes in people with atrial fibrillation by improving ABC.


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