Appropriate dosing of direct oral anticoagulants (DOACs) in Atrial Fibrillation (AF) is an international issue with literature demonstrating between 10-25% of patients prescribed an inappropriate dose. A majority of those are underdosed which comes with a recognised increased risk of treatment failure resulting in stroke. Overdosing increases the risk of major bleeding resulting in hospital admissions, anaemias, increased frailty and death not to mention a traumatic experience for the patient and their loved ones.
The Leeds DOAC AF dosing tool team consisted of 2 lead pharmacy technicians, 2 advanced pharmacists and a consultant pharmacist for anticoagulation and thrombosis. The tool was designed to identify patients with AF on the wrong dose of a DOAC and those whose monitoring is out of date based on the required monitoring frequency for that individual. Searches on SystmOne (S1) and EMIS were created to pull out all the necessary data required to calculate the correct dose of each drug, such as weight, age, creatinine and interacting medicines. Using a simple extraction method, data are then transferred on to an Excel based tool which highlights patients for review and recommends the correct dose and monitoring frequency. In addition, to support the Investment and Impact Fund (IIF) indicator CVD-06 % of patients on a DOAC for AF prescribed edoxaban, the tool also identifies those who might be clinically suitable for switching to edoxaban based on their weight (<120kg) and CrCl (<95mLs/min). The tool can be used for apixaban, edoxaban and rivaroxaban. Dabigatran is in development.
The tool was tested with several pharmacists and pharmacy technicians working for GP practices and primary care networks to iron out any issues and check clinical appropriateness before widescale rollout in April 2022. It also comes with full instructions on how to run the searches and import the data alongside clinical recommendations for reviewing patients safely. Baseline data showed that across the city 9-11% of patients were prescribed an incorrect dose and 55-60% were being incorrectly monitored (drug dependent).
Roll out was done through a city-wide engagement event with primary care pharmacists and pharmacy technicians and then shared via e-mail and via Microsoft Teams. Local teams have been using the tool to support IIF indicator SMR-03C (patients on DOACs having weight and CrCl calculated and dose adjustments made) and CVD-06 as above.
