Warfarin is the most widely used oral anti-coagulant however it has a narrow therapeutic range and it can take time to determine each patient’s optimum dose. Initiating warfarin risks bleeding events until the optimum dose is found. Genotype-guided dosing (GGD) offers a method of dosing which can potentially improve the safety of warfarin dosing. There are three implementation sites, comparative data is being collected from a further three sites not implementing genotype-guided dosing of warfarin and a second comparator has been collated using dashboard data. The analysis is comparing the implementation and comparator samples to assess whether the genotype-guided dosing improves patient health outcomes such as time in therapeutic range and number of bleeding events. Preliminary results have shown that time in therapeutic INR range (>4) is greater for those in the intervention sites. The number of patient visits is also being examined, serious adverse events and medication errors in addition to the cost-effectiveness of GGD to determine whether there has been an impact on service use and patient quality of life. In addition, the study is assessing both staff and patient views on the acceptability of the dosing method and is evaluating the implications of introducing genotype-guided dosing for staff and the patient pathway. Preliminary questionnaire data indicates that the method is acceptable to patients.
The implementation study is serving as an example to feed into a £2M NIHR Global Health Programme grant which is underway to take INR monitoring into parts of Africa.
Contribution of CLAHRC NWC
Matched funding was provided by partners. We received non-matched funding from LGC Ltd. The NIHR funds supported the administration and nursing time to collect data for the research element. Feedback has been provided to Chief Scientific Officer, Prof. Sue Hill and has influenced the content of the NHS Personalised Medicine Strategy.
What happened next?
Innovation Agency-led a successful grant application to roll out in other sites in the North West Coast. The implementation study is serving as an example to feed into a £2M NIHR Global Health Programme grant which is underway to take INR monitoring into parts of Africa. Our current algorithm is applicable only to white European populations, therefore this project will help to provide data to develop the algorithm and make it applicable for black African populations or people from black African descent which will subsequently be suitable for use in the NHS. Analysis is underway and if findings support wider implementation, we will work closely with partners to achieve this outcome. Findings relating to effectiveness and costs benefits will be published in peer reviewed publications and as a CLAHRC BITE.