Overprescribing of rivaroxaban in non-atrial fibrillation patients in primary care

The aim of the audit was very simple. Due to the complexity of the various licensed indications, doses and durations of rivaroxaban, the purpose of the audit was to ensure rivaroxaban was being prescribed in primary care for the correct duration of time, for all the shorter term indications, and that a clinical indication for rivaroxaban was clearly documented in GP systems (and in accordance with NICE TA170, TA261, TA287, TA335, SC1).

Licensed indications of rivaroxaban:

Prophylaxis of venous thromboembolism following knee replacement surgery:

10mg once daily (od) for 2 weeks.  (NICE TA170)

Prophylaxis of venous thromboembolism following hip replacement surgery

10mg once daily for 5 weeks (NICE TA170)

Initial treatment of deep-vein thrombosis or pulmonary embolism:

15mg twice daily for 21 days (NICE TA261 & TA287) then:   

Continued treatment of deep-vein thrombosis or pulmonary embolism (following initial treatment): 20mg once daily (NICE TA261 TA287).

Duration of therapy should be based on risk factors. Short duration of therapy (at least 3 months) should be based on transient risk factors (e.g. recent surgery, trauma, Immobilisation) and longer durations should be based on permanent risk factors or idiopathic DVT or PE.

Prophylaxis of recurrent DVT/ PE

20mg once daily  (NICE TA261)

Prophylaxis of stroke and systemic embolism in patients with non-valvular atrial fibrillation and with at least one of the following risk factors: congestive heart failure / hypertension/previous stroke or transient ischaemic attack, age >75 years or diabetes mellitus. 20mg once daily (NICE TA256)

Prophylaxis of atherothrombotic events in acute coronary syndrome (with aspirin alone or aspirin and clopidogrel) 2.5mg twice daily for 12 months usually.  (NICE TA335)

See BNF for dose reductions in renal impairment.

Rivaroxaban (Xarelto®) is a “DOAC” (direct oral anticoagulant), with a prescribing trend that is steadily rising. It has six licensed indications, with four different dosages and at least five possible durations of therapy, according to the condition being treated. ^.Anecdotal evidence suggests that patients have inadvertently remained on rivaroxaban long term when it was only indicated for short courses, e.g. deep vein thrombosis (DVT) treatment or post hip replacement in the older patient in a care home setting.

Prior to the licensing of rivaroxaban and other DOACS, patients anticoagulated with warfarin would have regular, planned contact with healthcare professionals for INR blood tests. However, patients on DOACs have no regular, co-ordinated follow-up for blood tests. Reviewing and stopping rivaroxaban in a timely manner can sometimes get missed, especially in elderly patients in a care home setting. This is exacerbated by the fact that rivaroxaban is also prescribed for the prevention of ischaemic stroke in patients with atrial fibrillation, which is a life-long treatment. This audit was designed to reduce the risks associated with inappropriate over treatment with rivaroxaban and in the process resulted in significant cost savings.

As a result of the audit cycle, 29 patients had their rivaroxaban stopped, which resulted in a potential annual saving of £19,000. Southampton has a city population of approximately 286,000, with 37,000 (12.9%) aged 65 or over.  It is a relatively “young” city, so the potential for greater cost savings and improved safety around DOACs in other areas of the UK, with significant older populations cannot be ignored.

The idea for this project arose whilst discussing rivaroxaban prescribing with GPs who had significant numbers of patients in a care home setting. A rivaroxaban audit toolkit was then written by the Medicines Management Team of the CCG, after this discussion. This “toolkit” consisted of an audit template, a data collection form and detailed instructions for running the computer searches to find the relevant rivaroxaban patients on GP clinical systems. The audit standards are listed below:

Audit standards (Target 100%) 

1. Patients on rivaroxaban have an indication (reason) clearly documented.
2. Duration of rivaroxaban treatment is documented in patient’s clinical notes/ letters.
3. Patients on defined courses of rivaroxaban are currently within the intended duration of treatment.

The complete audit cycle was successfully undertaken by all 30 GP practices in Southampton, as part of the annual Prescribing Incentive Payment Scheme for Southampton City CCG during 2016-17. This involved an initial data collection, feedback to GPs and implementation of key actions raised. This was then repeated 3-4 months later as a re-audit.

Table 1 shows the range of indications rivaroxaban was prescribed for. Table 2 shows how improvements have been made as a result of this audit.

In the initial audit 73% of rivaroxaban prescribing was for stroke prophylaxis in atrial fibrillation. This is a life-long therapy and these 892 patients were excluded from the audit.

The remaining 27% (328 patients) had rivaroxaban prescribed for non-atrial fibrillation indications. Of that group, 8% (26 patients) were inappropriately overprescribed rivaroxaban according to the intended duration. A further 3 patients were found in the re-audit, 4 months later. All 29 patients had their rivaroxaban therapy stopped as a result of the audit flagging up the intended duration, which had been exceeded.

Additionally 33 patients had “treatment end dates” added to their rivaroxaban prescriptions to avoid overprescribing beyond the intended duration. Of the 328 patients in the initial audit cohort, 104 (32%) were in a care home.

Table 1: Range of indications

Table 2: Adherence to standards

With careful searching on GP clinical systems, the number of patients to include in the audit was reduced to manageable numbers, purely by eliminating those with a diagnosis of atrial fibrillation. Most GP practices had only a small audit cohort of patients, once long term AF (usually lifelong) rivaroxaban patients were eliminated.

Although the results of the audit often flagged up a GP’s omission, GPs were very grateful to have the over prescribing flagged to them and acted upon the findings promptly. In some circumstances the indication for the rivaroxaban had been poorly shared between primary and secondary care and hence a “stop” date had not been documented in GP clinical systems because it was not known.

If this audit work were to be repeated, it may be useful to collect data on who initiated the DOAC and whether adequate information had been provided to the GP, when it had been initiated in secondary care. Steps could then be made to educate the appropriate clinics/ wards in local hospitals, regarding the importance of stating a duration of therapy in discharge correspondence concerning anticoagulation.

This project may be extended to cover all DOACs, (including apixaban, dabigatran, and edoxaban) which all have multiple indications, doses and durations of treatment.

It is a very simple audit to undertake to improve patient safety around anticoagulant over-prescribing and due to the high cost of DOACs; the financial savings made for the NHS have been considerable.