Anonymised patient data from the records of 1,500 GP practices using EMIS Web has enabled a major new study for the National Institute for Health Research School for Primary Care Research (NIHR SPCR) into the risks and benefits of modern anticoagulant drugs.
Researchers used the QResearch database – which draws on routinely captured data from participating EMIS practices – for their study comparing the health outcomes of patients treated with three commonly-prescribed direct oral anticoagulants (DOACs) with those treated with warfarin.
Researchers analysed data from the primary care records of almost 200,000 people, comparing two large groups over a five-year period. One group had abnormal heart rhythm, the other a range of other conditions treated with anticoagulants.
The results of the study will provide important new evidence on the safety profile of the different anticoagulant medications and help doctors make better prescribing decisions.
The study found:
- Apixaban was the safest drug, with reduced risks of major bleeds, intracranial and gastro-intestinal bleeding compared with warfarin.
- In the group with abnormal heart rhythm, dabigatran was linked to a reduced risk of intracranial bleed, while rivaroxaban was linked to a reduced risk in the group with other conditions.
- Rivaroxaban and low dose apixaban were associated with increased risks of all-cause mortality compared with warfarin in both groups of patients.
More work is needed to understand the implications of some of the findings for real world clinical practice. DOACs are not suitable for all patients who require anticoagulants – for example, prosthetic valve cases still require warfarin.
QResearch® is a non-profit making venture run by the University of Nottingham in collaboration with EMIS Health. More than 1,500 EMIS practices, representing around 30 million patient lives, contribute anonymised data to the database.
Dr Shaun O’Hanlon, Chief Medical Officer of EMIS Group, said: “This important study is the latest in a long list of research projects that has been powered by real-life data collected from thousands of GP consultations every day.
“We are grateful to the 1,500 GP practices that support QResearch; without them, this important initiative would not be available to help to improve the health of the nation. It is fitting in the 70th anniversary year of the NHS that we have been able to support such a landmark study.”
University of Nottingham Professor of Clinical Epidemiology and General Practice, Julia Hippisley-Cox, who initiated the study, said: “This is a very important study with ‘real world’ evidence on which of these medications have the best safety profile. This will help doctors make better decisions when prescribing these commonly used medicines for patients in primary care.It is important to state that patients on anticoagulants who have any concerns should consult their GP at their next review meeting.”
The lead author of the study, Dr Yana Vinogradova, said: “The results of this large new study are important because previous research using randomised controlled trials has only included carefully selected patients who are closely monitored. Other observational studies have in most cases concentrated solely on patients with atrial fibrillation (abnormal heart rhythm) so until now there has been no overall picture of information for use of anticoagulants in other patients.”
Professor of Medical Statistics in Primary Care, Carol Coupland, a member of the research team said: “Our study shows that analysis of routinely collected primary care data can shed detailed light on health outcomes in a much wider group of patients taking anticoagulants.”