Improving the safety of long term anticoagulant prescribing

Tiffany Barrett, Interim co-director, South West Medicines Information and Training, NHS England SouthExample from Oxford University Hospitals NHS Foundation Trust, in collaboration with Oxford CCG and Oxford Academic Health Sciences Network (OAHSN)Published
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Summary of the example

NICE guidance on atrial fibrillation (AF) recommends that patients on anticoagulation with warfarin should have time in therapeutic range (TTR) assessed. Patients with TTR <65% should be reviewed to try and improve control; for some new direct oral anticoagulants (DOACs) may be suitable.

Oxford University Hospitals (OUHFT) provides a ‘dose and post’ warfarin service, managing 8000 patients (5600 with AF). Whilst this service benchmarks well (mean TTR 72%), analysis in 2016 showed that 2125 patients had TTR <65% (1500 with AF). Oxfordshire GPs are responsible for review of anticoagulation control and DOAC initiation. Informal feedback suggested not all GPs felt confident to do this.

This project assessed the needs of a local population and found that prescribers wanted more support to ensure safe prescribing and monitoring of warfarin and DOACs. As a result of the project, the Oxford CCG, Oxford AHSN and Oxford University Hospitals Foundation Trust agreed to a collaborative project to encourage anticoagulation optimisation. They have funded 1.5 WTE pharmacists for 1 year to provide an email/telephone service, outreach support and centralisation of guidelines. Feedback of the service so far is positive and time in therapeutic range (TTR) data will be reviewed regularly to analyse impact.

Why we think it’s important

Warfarin is widely used in both AF and non-AF therapeutic indications. DOACs are becoming more commonly prescribed for AF and non-AF therapeutic indications. Those involved in the prescribing and monitoring of both warfarin and DOACs need to be confident and competent in doing so.

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Aims and objectives of the work

Oxfordshire GPs are responsible for review of anticoagulation control and DOAC initiation. Informal feedback suggested not all GPs felt confident to do this. The initial aim of the project was to determine the anticoagulation educational and service needs of Oxfordshire GPs and make recommendations for improvement.


OUHFT and Oxford Academic Health Science Network (AHSN) sent a questionnaire to all Oxfordshire GP practices in April 2016 to assess levels of knowledge and competence in the management of anticoagulation using warfarin and initiating and managing DOACs.

Key findings

76 responses were received from individual GPs. 43% of GP respondents did not feel confident in assessing anticoagulation control on warfarin; 67% did not feel confident in their knowledge of DOACs and 53% did not feel confident in prescribing DOACs. Additional services considered useful: email support (77%), telephone advice (49%), education & training (49%), specialist pharmacist outreach support (30%), centralised DOAC initiation (45%). 37 respondents provided comments which were thematically coded, some containing multiple codes. Themes included: education/outreach (13), centralised information resource and local guidance (11), time pressures (9), resources and cost (9), safety concerns (2).

These results led to collaborative project between OUHFT, Oxford AHSN and Oxford CCG to encourage anticoagulation optimisation. The project’s aim is to upskill both GPs and community pharmacists.

1.5 WTE specialist anticoagulation pharmacists, with haematology consultant support, provide:

  • Email/telephone advice
  • Educational sessions and note-based TTR reviews in GP practices
  • Education sessions for community pharmacists to help effectively deliver the New Medicines Service and Medicines Use Reviews to patients on anticoagulants

Collaboration between OUHFT and OCCG is critical to success, including centralisation of protocols, a review of guidelines, plus initiation of a new service tariff for GPs to support TTR review.

Feedback from GPs following outreach support is positive: 100% agreed/strongly agreed that the content, structure and presentation of the session were appropriate; all GPs would recommend the educational session to colleagues. The GP practice TTR data at 3 and 6 months following intervention will be analysed for impact.

Whilst a centralised initiation DOAC service was popular, it was not feasible with the funding available. The strengths of the current service are its widespread upskilling to improve safety of these commonly prescribed medicines. If proven successful, it will be requested as a commissioned service in order to continue to support and improve safe and optimal anticoagulation in a rapidly evolving area.


Below are the project report and abstract accepted by the British Journal of Haematology.



National guidance, data and publications

Atrial fibrillation (AF) is the most common cause of cardiac arrhythmia and is a major cause of stroke, TIA and systemic embolism and has a prevalence of 1.6% of the whole population of England. The risk of a stroke is five times higher in a person with AF than in a person in sinus rhythm and stroke severity is usually greater when stroke is associated with AF than with other causes. Anticoagulation treatment reduces the risk of stroke by about two-thirds (NICE CKS). Anticoagulation is achieved using either warfarin or DOACs. With warfarin there are issues about maintaining the INR in the therapeutic range to ensure adequate anticoagulation. DOACs are newer agents which don’t require routine INR monitoring but do present their own issues including dose adjusting in renal impairment. The consequences of warfarin or NOACs being poorly managed may be severe for the patient.