Antibiotic treatment and major bleeding in anticoagulant medication users: analysis of health record data to support safer monitoring and prescribing

The main oral anticoagulants used in the UK are warfarin and a group of drugs known as Direct Oral Anticoagulants, or DOACs. Their main use is to prevent blood clots and stroke in people with an irregular heart rhythm. Bleeding is the most serious complication of using anticoagulant medication. Several antibiotics are thought to interact with anticoagulants and increase the chance of a major bleed. However, the available research does not clearly identify which antibiotics are safe and prescribing advice is mostly based on anecdote. It is important to know which antibiotics increase the risk of bleeding to enable healthcare professionals to avoid potentially harmful antibiotics but appropriately prescribe those that are safe.

This project aims to determine the risk of major bleeding associated with antibiotic treatment in anticoagulant medication users and effectively disseminate the findings to improve care and help reduce the incidence of these adverse outcomes.

Urinary, or skin infection.

Analysis 3 will determine the risk of bleeding in people with an infection that did not need antibiotic treatment and will answer the question of whether infection alone is associated with the risk of bleeding. Each analysis will also investigate which patients are most at risk and when risk is greatest. This will provide important information about which patients and time-periods may benefit from closer monitoring and improve the overall care provided to patients.

Patient and public involvement

Members of the Wales Centre for Primary and Emergency Care Research Service Users group (SUPER) reviewed this summary, as did two patient and public representatives who worked with the applicant on previous CPRD research. Going forward, this project will collaborate with a lay advisory group recruited from the SUPER group and Anticoagulation UK. The applicants training and development plan includes training to improve his skills in maximising the potential benefits from patient and public involvement in data science research. The requested time and finances will enable meaningful patient and public involvement throughout the lifespan of the project.

Dissemination

The findings of this project will be disseminated to organisations that write clinical guidelines (for example, NICE, Public Health England), and to NHS staff. The applicant will work with patient and public involvement representatives to develop lay summaries of the findings and ensure that these reach the wider public. Thrombosis UK and Anticoagulation UK will support the dissemination activities through their network of healthcare professionals and anticoagulant medication users.