Title: Redesign and implementation of a deep-vein thrombosis pathway reduces healthcare utilisation costs and improves patient care

Authors: Matt Fay, Sam Ackroyd, Carol Aitken, Mark Kon, Robert Halstead, Clare Smart, Greg Fell

Author details:

Matt Fay, GP with a Special Interest in Cardiology, Westcliffe Medical Centre, Shipley,UK

Sam Ackroyd, Consultant Haematologist, Bradford Royal Infirmary, Bradford, UK

Carol Aitken, Lead Pharmacist, Medicine, Bradford Royal Infirmary, Bradford, UK

Mark Kon, Consultant Radiologist, Bradford Royal Infirmary, Bradford, UK

Robert Halstead, Emergency Department Consultant, Bradford Royal Infirmary, Bradford, UK

Clare Smart, Head of Service Improvement, Bradford Districts Commissioning Clinical Group, Bradford, UK

Greg Fell, Consultant in Public Health Medicine, Bradford Metropolitan District Council, Bradford, UK

Corresponding author:

Dr Matthew Fay GP Principal, Westcliffe Medical Practice Westcliffe Medical Centre, Shipley, BD18 3EE, UK Telephone: 01274 580787Email: matthew.fay@bradford.nhs.uk

Keywords: deep-vein thrombosis; pathway redesign; rivaroxaban; cost-analysis

Word count: 3,919

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ABSTRACT

The current patient care pathway for acute deep-vein thrombosis (DVT) requires clinicians in primary care to refer patients with suspected DVT to hospital for diagnosis, who then often experience significant delays in receiving treatment in busy accident and emergency (A&E) departments and medical assessment units (MAUs), with associated cost implications. If confirmed, patients are discharged on low-molecular-weight heparin and warfarin, with community monitoring until stable. Overall, the pathway is poorly understood and there is poor compliance from both patients and clinicians. To address this, the DVT pathway in Bradford was redesigned so that all patients are assessed in primary care, and those with suspected DVT are initially treated with rivaroxaban. Patients with confirmed DVT continue to be managed as an outpatient, thereby reducing hospital admissions.

This paper reports the economic impact of the redesigned pathway in a population of 440,000 patients in Bradford, UK. After considering the cost of additional diagnostic testing in general practice and supply of rivaroxaban to all patients with suspected DVT, a significantly reduced number of MAU and A&E admissions resulted in a net saving of £230,453. For those patients with confirmed DVT who continue to receive rivaroxaban, reduced spending on international normalised ratio clinics contributes to a further saving of £28,280. Taken together, the redesigned DVT pathway provides a significant cost saving of approximately £260,000 compared with the previous hospital-based model. The pathway is also expected to increase patient compliance with disease management and therefore improve overall health outcomes.

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INTRODUCTION

Acute deep-vein thrombosis (DVT), as a component of venous thromboembolism (VTE), is a common and potentially life-threatening disorder.1,2 Despite data suggesting that VTE is the third most prevalent cardiovascular disease3,4 with an incidence exceeding 1 per 1,000,5 the true disease burden is typically underestimated.

In Europe, the VITAE (VTE Impact Assessment Group in Europe) epidemiological modelling study estimated that the annual number of symptomatic VTE events within the six participant EU countries was more than 466,000 cases of DVT and 370,000 VTE-related deaths.6

The diagnosis of DVT relies on clinical suspicion, followed by the combined use of a Wells score and D-dimer assay, confirmation sonography, and intervention with anticoagulation as soon as possible;7 especially if there is a delay in obtaining imaging. Short-term treatment is effective, reducing the risk of recurrent disease from 25% to approximately 3% during the first 6 to 12 months.8 However, the risk of recurrence remains, reaching 5 to 10% during the first year following treatment cessation.9,10 A notable and burdensome complication of DVT is post-thrombotic syndrome (PTS), which develops in approximately 20% of patients within two years of DVT.9 Since treatments for PTS are not very effective, PTS is ideally averted with the use of effective anticoagulation therapies, which should be initiated as soon as DVT is suspected.11

Rivaroxaban, an oral direct Factor Xa inhibitor administered as a fixed dose, has a predictable pharmacokinetic profile, and does not require routine monitoring.12,13 In patients with acute DVT, rivaroxaban showed similar rates of recurrent thromboembolic events and bleeding compared with current standard treatment of low-molecular-weight heparin (LMWH), followed by a vitamin K antagonist (VKA);10 usually warfarin in the UK.14

The current diagnostic and treatment pathway requires clinicians in primary care to refer patients to a service capable of initiating the parenteral LMWH and arranging diagnostics. Historically, in Bradford, West Yorkshire, most patients with suspected DVT were referred to hospital for diagnosis, and often experienced significant delays in receiving treatment in busy accident and emergency (A&E) departments and medical assessment units (MAUs), with associated cost implications. If confirmed, patients were discharged on LMWH and warfarin with community monitoring until stable.15 Following this, patients frequently did not receive an outpatient review by a haematologist to assess the underlying cause of their DVT; and owing to a lack of formal DVT follow-up clinics, they were monitored at hospital anticoagulation clinics. Overall, the pathway was poorly understood and there was poor compliance from both patients and clinicians, which increased the risk of poor treatment outcomes.

However, a widespread acceptance that the majority of non-complex patients can be managed in an outpatient setting,5,7 and the use of rivaroxaban at patient presentation, permits the pathway to become diagnostic rather than focused on therapy manipulation; this is the Bradford DVT model.15 This paper discusses the development and implementation of the Bradford pathway, associated patient outcomes, and cost-effectiveness over a 12-month period.

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DIAGNOSTIC PATHWAY REDESIGN

The Bradford DVT pathway protocol was based on the open-label, event-driven EINSTEIN study, which provided a single-drug approach to the short-term treatment of DVT with rivaroxaban, without the need for coagulation monitoring.14

Initial work on the protocol involved primary-care consultation with all general practitioners (GPs) across two clinical commissioning groups (CCGs) in Bradford. A concurrent process with secondary-care clinicians, particularly radiology, haematology, and acute medicine, was also undertaken. A pathway for use by A&E was developed in parallel to that used in primary care, which followed the same treatment-based protocol; patients were discharged to their GP, with admission of high-risk patients only.

In summary, the primary-care protocol directs the clinician, who initially examines the patient, to perform a Wells score if symptoms and signs consistent with a possible DVT are observed.16 A prompt D-dimer and electrolyte assessment is arranged and a 21-day supply of rivaroxaban 15 mg b.d. is prescribed in place of the traditional hospital admission, followed by LMWH plus loading doses of warfarin. The clinical situation is explained to the patient, which is supported by information supplied by the manufacturer. Once the blood results are available, a DVT pro forma, including the D-dimer result and a request for a venous ultrasound, is faxed to the radiology department (Figure 1).

Diagnostic outcomes from hospital sonographers return one of three basic instructions to the primary-care physician, who retains clinical responsibility for the patient. DVT is confirmed by a positive scan, and DVT continues to be suspected following a negative scan but a positive D-dimer assay (Figure 2). The protocolled process following DVT confirmation is to continue rivaroxaban at 15 mg b.d. for 3 weeks, then change to a lower dose of 20 mg o.d. for 3 to 12 months, depending on whether the DVT is provoked or unprovoked and other ongoing risk factors for recurrence. Where ultrasound suggests that DVT is still suspected, rivaroxaban is paused until the repeat scan a week later, as initiated internally by the imaging department. Where there is a negative scan and negative D-dimer assay, patients should be discontinued from rivaroxaban and an alternative diagnosis considered.

Patients with confirmed DVT are subsequently scheduled to attend a thrombosis clinic and reviewed under the supervision of a haematologist within 4 weeks of diagnosis. Patient permission to share primary-care records with the haematology clinic should be sought at initial diagnosis.

This pathway is not suitable for every suspected DVT presentation. High-risk patients on anticoagulation therapy, such as those with a known history of bleeding disorders, total immobility precluding ambulatory care at home, and pregnant or breast-feeding mothers, were excluded from the pathway. In addition, patients presenting with pulmonary embolism (PE) or other medical conditions necessitating secondary-care admission were not included.16

IMPACT OF THE REDESIGNED PATHWAY

There was widespread support from both primary and secondary-care clinicians during the development and implementation of this pathway. There was also a strong clinical consensus that

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the pathway is of high quality, safe, and more convenient than the current model utilising LMWH. It was largely considered that the protocol change would generally improve outcomes for patients.15

In addition, by implementing a thrombosis clinic follow up 1 month after diagnosis, the continuity of patient care improved. This was associated with the improved IT functionality, ensuring the lead haematologist had access to patient primary-care records. In the previous system, patient follow-up occurred on a rather ad-hoc basis.

Initial feedback from patients (shared by referrers) suggested that the new DVT pathway was effective and appropriate, enabling patients to remain at home safely with their families. Our first patient was frail, vulnerable to infection and remained in his care home rather than being admitted to hospital; excluding the initial scan, his DVT was managed completely at home.15

However, implementation of the new pathway may result in a loss of patient throughput for secondary-care anticoagulation services, representing a net loss of income for that service. The potential risk of destabilising secondary-care services may be balanced by moves to increase anticoagulation treatment for patients with atrial fibrillation (AF).16 Data extrapolated from the Guidance on Risk Assessment and Stroke Prevention (GRASP) study17 estimate (using a CHADS2 risk score of ≥1 as the threshold for anticoagulation) there will be 1,800 untreated AF patients requiring anticoagulation across a population of 500,000.

The Bradford DVT pathway moves patient diagnosis and management from a secondary to primary-care-based model, with few hospital admissions. Such a change in focus resulted in an 80% reduction in MAU admissions for suspected DVT; estimated at approximately 1,000 admissions saved per year.15 As a result, it was necessary to ensure the change of workflow was reflected in contracts with providers; specifically, the reduction in contracted patient volumes attending A&E/MAUs and the increased numbers attending radiology and the thrombosis clinic; i.e., moving income (within the provider) out of A&E/MAUs and into radiology and haematology.

With the majority of patients managed in primary care, the Bradford DVT pathway was designed to be of lower cost, with better patient experience and improved health outcomes compared with the traditional model. Our experience suggests it is considerably simpler to develop a clinical consensus than address institutional barriers to implementation, which require strong direction from commissioners.

ECONOMIC EVALUATION OF THE REDESIGNED PATHWAY

The National Institute for Health and Care Excellence (NICE) Technology Appraisal 261considered rivaroxaban to be cost-effective for up to 12 months of treatment, and dominated LMWH plus VKA therapy over a 3-month period.12 The incremental cost-effectiveness ratio (ICER) was £3,200 per quality-adjusted life-year (QALY) gained for the 6-month treatment duration, and £14,900 per QALY gained for the 12-month treatment duration.12 However, the model used was sensitive to the length of anticoagulation and the cost of international normalised ratio (INR) clinics, but not the protocol used; i.e., therapy manipulation, not the diagnostic and treatment pathway. The manufacturer’s financial model predicted a substantial net saving for NHS Bradford Airedale (NHS Bradford City and Bradford Districts CCGs); although, this was also focused exclusively on a treatment switch between LMWH/VKA and rivaroxaban.

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Our Bradford DVT pathway cost model was based on a 440,000 patient population (across two CCGs), and developed using assumptions that were based on extensive clinical experience, the available evidence, and local data. Here, we report the economic impact of the diagnostic and treatment components of the redesigned pathway for managing DVT in community-presenting patients.

Diagnostic component of the pathway

Evaluation of the diagnostic component of the pathway focuses on GP and A&E requested scans, as the pathway redesign did not affect scans requested as a result of outpatient consultation or hospital admission. There were 828 scan requests for suspected DVT by GPs and 135 requests by A&E clinicians – a total of 963 community-presenting patients with suspected DVT, which equated to 58% of the total number of suspected DVT at Bradford Teaching Hospitals during 2014 (Table 1).

Based on an estimate that 29% of initial presentations with suspected DVT can be ruled out by Wells score and D-dimer testing (<1.2% risk, Wells rule ≤1 combined with a negative D-dimer test),18 we assumed that there would be an additional 393 patients in general practice or A&E with suspected DVT that would be ruled out as a result of their Wells score and D-dimer test result. Given that 14% of scans are initiated in A&E, we estimated that DVT would be ruled in 55 A&E patients who would then not need to undergo a scan. An additional 338 patients presenting to general practice would also have their suspected DVT ruled out and also not need require a scan. The avoided A&E attendance in this latter cohort has not been factored into our economic evaluation. However, assuming a tariff of £109 (category-2 investigation and one treatment), this equated to a saving of £37,000 on A&E attendance from a commissioner perspective.

After considering negative D-dimer test results and low Wells score, we estimated that a total of 1,356 patients would present with suspected DVT – 1,166 patients to general practice and a further 190 patients to A&E. Notably, prior to the implementation of the redesigned pathway, all patients with suspected DVT would have been seen in A&E then admitted to the MAU. It was also not uncommon for all scans on community-presenting patients with medium-risk DVT to be performed in an MAU or similar to mitigate the 4-hour waiting time target set out in The NHS Plan, 2000.19

Costs associated with the diagnostic component of the pathway

The cost of implementing this community DVT pathway involved some additional work in general practice. All 1,356 patients, who either presented to general practice or A&E, required a Wells score and D-dimer test, which at a cost of £7 per test, amounted to £9,500. There was also the cost of the additional GP time required to carry out this testing, which we did not consider in this analysis. Implementing the redesigned pathway also resulted in the additional cost of prescribing an initial pack of rivaroxaban to all patients presenting with suspected DVT. In our analysis, we assumed that a 21-day supply of rivaroxaban is given to all patients, at a cost of £2.20 per day at a total expenditure of £62,700. The additional presentations to A&E were incorporated into this, as the CCG now pays for the A&E tariff, as opposed to historic MAU admission. In addition, the 963 scans were paid at a cost of £57 per scan, or £55,000. Thus, the total cost of implementing the diagnostic component of the pathway was £127,147.

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Savings associated with the diagnostic component of the pathway

A total of 936 MAU admissions were avoided at a cost of £321 per admission, or £309,000, with an additional £37,000 saved by not requiring A&E appointments – a total of £346,000. To put this admission reduction into further context, there are approximately 40,000 non-elective admissions across the two Bradford CCGs each year. A reduction of 836 MAU admissions therefore equates to a 2.3% reduction in total non-elective volume.

There is also cost saving associated with not having to prescribe a 7-day supply of dalteparin at a cost of £10 per patient. Dalteparin would have been given to all 1,166 patients presenting to their GP, thus saving £11,600. It would also have been given to patients presenting to A&E, but this cost would have been covered by the tariff, and is not included in our analysis for this reason. Furthermore, implementation of the pathway frees up community nursing time to focus on other higher-value activities. Again, we did not consider this in our analysis as the benefit was not readily quantifiable.

Taken together, we estimated the net saving associated with the diagnostic component of the pathway to be £230,453.

Treatment component of the pathway

For the treatment component of the pathway, we focused on the 112 community-presenting patients with a positive scan (Table 1). These patients were commenced on rivaroxaban and will be followed up in a thrombosis clinic. Notably, prior to the pathway redesign, these patients would have had a review as part of the INR clinic at Bradford Teaching Hospitals.

Cost of rivaroxaban

Our assumption, based on the NICE rivaroxaban costing template12 (considered locally to be accurate), is that 42% of patients would receive 3 months’ anticoagulation, 33% would receive 6 months, 7.5% would receive anticoagulation for 1 year and a further 7.5% would receive anticoagulation for 2 years or more. At the current list price of £2.20 per day, we estimate the cost of implementing rivaroxaban treatment in a cohort of 112 community-presenting patients with confirmed DVT to be £52,600.

Savings associated with a lower use of INR clinics

There should be a reduced spending on INR clinics as patients are no longer monitored there. An estimate of INR clinic spending can be calculated from an assumption about visit volume. A previous study of resource utilisation in secondary-care-based anticoagulation services found that patients receiving 3 months’ anticoagulation made nine visits to an INR clinic, which increased to 24 visits for patients receiving 12 months’ anticoagulation.20 Locally, this was considered to be a slight overestimate but reasonably accurate for the purposes of our analysis. Applying these estimates to our local population; we estimated that by implementing a rivaroxaban pathway, we have avoided 1,700 INR clinic visits. At a cost of £58 per visit, this equated to a saving of £101,000.

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Cost of thrombosis follow up

All 112 patients with a positive scan should be reviewed in a thrombosis clinic as a haematology outpatient, at cost of £243 per patient. Prior to the implementation of the DVT pathway, patients would have received some follow-up care, including assessment of aetiology and length of anticoagulation required, as part of an INR clinic appointment. Thus, we estimated an additional cost per patient of £185 per follow-up appointment in a thrombosis clinic, which equated to a total expenditure of £20,720.

Thus, when also considering the cost of rivaroxaban and the saving associated with a lower use of INR clinics, we estimated the net saving associated with implementing the treatment arm of the pathway to be £28,280.

Economic impact of the redesigned pathway

Overall, the total net saving associated with implementing the diagnostic and treatment components of the redesigned pathway in a population of 440,000 patients is £258,733. This equates to an estimated saving of £588,029 per million patients. This estimate, however, is sensitive to the assumptions and cost parameters used in our analysis, which may vary from place to place.

Additional work in general practice

One of the common complaints associated with this pathway is the additional work it generates in general practice, which represents a transfer of work from hospital to general practice that is not recompensed. In our population of 440,000 patients, we estimated that there are approximately 1,356 presentations to general practice per year. This equates to approximately 3.8 presentations per 1,000 registered patients in a year, or for a GP practice with 10,000 registrations, approximately 38 presentations per year – less than one per week. As outlined above, the additional work for managing these patients involves performing a Wells score and D-dimer test, and arranging a scan for those with suspected DVT (approximately 70% of patients). Therefore; although this pathway creates some additional work for GPs, it is unlikely that it would significantly increase the overall patient caseload of a typical GP practice.

Limitations of the analysis

There are a number of caveats associated with our analysis of the economic impact of the redesigned pathway. These are mainly due to the availability of data to demonstrate cost-effectiveness from a NHS commissioner perspective. This approach arguably underestimates costs that are already within a system, such as the additional work within the scope of the GMS contract, or work within the tariff income of a provider. Moreover, routinely available data on all components of this pathway are not accessible from a single place – certainly from a commissioning perspective. This analysis is therefore limited by our assumptions surrounding the patient scan data, for which there is a definitive tariff.

THE REDESIGNED PATHWAY IN ACTION – AN AUDIT OF CURRENT PRACTICE

Data from all patients entering the Bradford DVT pathway were collected and audited over a year (May 2013 to April 2014). Overall numbers suggest that 9.75% of primary-care referrals were

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positive for DVT following an ultrasound scan, compared with 23% of A&E referrals (Table 2). This perhaps is not surprising, as patients with more worrying symptoms might prefer to seek urgent hospital attention.

While GP referrals and treatment with rivaroxaban was appropriate in 99 cases, there were 916 instances (90%) where therapy was prescribed and subsequently stopped. Thus, the majority of prescriptions for rivaroxaban in this pathway were ultimately unnecessary (15 mg b.d. for 21 days at £2.20 per day or £46 per patient).

A common difficulty highlighted by GPs was the lack of access to a D-dimer measuring device. It was considered that point-of-care D-dimer testing would significantly ease the management of patients within the DVT pathway. This is something that will be addressed in the future, and is expected to bring further savings.

As a result of this patient population attending a thrombosis clinic, the number of patients undergoing computed tomography (CT) scans had increased (Table 3). In total, 39.7% of 78 patients attending the thrombosis clinic presenting with an unprovoked DVT was followed up by a CT scan (as required by local and national guidelines), which was reviewed by a consultant haematologist. Subsequent matters of concern were detected in 41.4% of cases (12 out of 29 CTs performed); 25% of identified cases (n=3) were the detection of previously undiagnosed cancers. The introduction of the new pathway has markedly improved monitoring of patients for malignancy as a possible cause of DVT. By comparison, a retrospective survey of patients previously treated for unprovoked DVT in a local anticoagulant clinic in 2012 demonstrated that only 25.9% of patients with unprovoked DVTs underwent CT assessment.

The new pathway also highlighted the value of the hospital thrombosis clinic (which is run by two pharmacists working under the supervision of a consultant haematologist). The thrombosis clinic ensures that NICE guidelines that relate to each patient’s clinical condition are followed. In Bradford, with 99 patients having their DVT diagnosed by their GP annually, the probability is that an individual GP in the city will only see fewer than one confirmed DVT case each year. It is, therefore, important to have a process that checks that every GP has considered the various implications of a positive DVT diagnosis and has carried out appropriate monitoring and necessary prescribing adjustments when commencing rivaroxaban treatment. In an acute setting, where prior to the ultrasound scan the GP is uncertain about the continued need for rivaroxaban therapy, it is important to ensure that drugs such as aspirin, which may interact with rivaroxaban, or drugs such as oestrogens, which may have precipitated the DVT, are not overlooked when making a final diagnosis. As part of standard protocols, the thrombosis clinic reviews and rectifies any prescribing issues that may occur following initiation of rivaroxaban, such as dosing levels in patients with renal failure (Table 4).

CONCLUSION

The development of the Bradford DVT pathway represents an important shift in the DVT model of patient care. It permits diagnosis and management to move from a hospital-based scenario to one owned by the patient’s GP. Data from the CCGs involved demonstrate that the pathway not only provides significant cost savings of approximately £260,000 compared with the previous hospital-based model, but also increases patient compliance with disease management and will deliver improved health outcomes. In addition, given the poor compliance with the current, national model,

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the Bradford DVT pathway may deliver even more health benefits in the real world, such as a reduced incidence of PTS. Although this is arguably impossible to measure or cost, it may be a substantial downstream benefit given the incidence of PTS post DVT and the evidence showing that the speed and quality of anticoagulation are significant protective factors for PTS.

As the majority of our DVT patients are now managed by their GP in a local setting, care is provided closer to home in a convenient and safe environment. With direct GP access to diagnostics and treatment with rivaroxaban, audit data demonstrate a significant reduction in hospital admissions for suspected DVT. Furthermore, as the thrombosis clinic referral is now initiated at the point of diagnosis, there is also a reduction in the number of clinical handovers where patients have the potential to be ‘lost’ in the system, ensuring an improved standard of care.

It is critical to highlight the importance of ongoing collaboration between GPs, radiology and haematology departments within the new pathway. Considerable responsibility falls on secondary care to ensure that pathway processes are safe and adhere to new research findings; ongoing haematology input is essential. We also found a high level of professional collaboration, not only with sharing of patient electronic records and logistical pathways through imaging, but also with haematologists receiving correspondence from GPs requesting advice and reassurance.

Our experience of this new DVT pathway suggests that a primary-care-focused redesign of diagnostics and patient management would be easily and readily replicated by other CCGs. It has enabled us to improve patient care and outcomes without a net increase in cost. For wider implementation, the pathway would simply require localisation and clinical agreement with secondary-care suppliers to ensure contracts reflect alterations in the clinical workflow.

The next stage of the Bradford DVT pathway is to establish a financially sustainable means of convenient D-dimer testing in the community setting, and determine if the redesigned pathway has reduced the incidence of PTS. We also plan to explore the treatment of low-risk PE in a similar community model.

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Competing interests

We have read and understood BMJ policy on declaration of interests and declare the following interests:

Dr Matt Fay is a partner of Westcliffe Medical Practice, which has received funding from pharmaceutical companies, including Bayer HealthCare, Abbot, Boehringer-Ingelheim, Bristol Myers Squibb, Dawn, INRStar, Medtronic, Oberoi Consulting, Pfizer, Roche, Sanofi-Aventis, Servier. Dr Fay is also a member of the AF Association, Arrhythmia Alliance, National Stroke Association, SPAF Academy and Syncope Trust.

Mr Greg Fell is an employee of Bradford Metropolitan District Council, which has received funding from Bayer HealthCare.

Acknowledgements

Medical writing and editorial support was provided by Dr Anthony Zucker, apothecom (London, UK).

Funding

This work was supported by an unrestricted educational grant from Bayer HealthCare UK.

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Tables and Figures

Figure 1. DVT pathway in primary care – the GP role

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Figure 2. DVT pathway GP algorithm – diagnosing DVT

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Table 1. Scans for suspected DVT at Bradford Teaching Hospitals (January 2014 to December 2014)

Referrer Patients, n Patients with a negative scan, n

Patients with a positive scan, n

Positive scan rate

Inpatient 580 501 79 13.6

Outpatient 113 103 10 8.8

A&E 135 103 31 23.0

GP-initiated 828 747 81 9.8

Total 1657 1455 202 12.2

Note: These are administrative data for contract monitoring purposes.

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Table 2. Ultrasound testing for DVT (May 2013 to April 2014)

Total number of patients suspected of DVT 1271Total ultrasound scans carried out 1565

Ultrasound test requested by GP 1015Test requested by a hospital doctor 550

Total number of repeat ultrasound tests 294

Repeated once 262Repeated twice 30Repeated three times 2

Positive tests 188GP origin 99Hospital origin 89

Positive tests seen on repeat1st repeat 52nd repeat 93rd repeat 1

Patients where the scan showed a recurrent DVT 3Hospital patients where the DVT was discovered on repeat ultrasound 5GP-referred patients where the DVT was discovered on repeat ultrasound 10

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Table 3. Clinical results from the thrombosis clinic (May 2013 to April 2014)

Patient referred to the thrombosis clinic after a positive ultrasound scan for VTE 99Number of patients who attended 78Number of patients who did not attend 21

Results from CT scansNumber of patients where a CT scan was thought necessary 31Patients where the CT showed no apparent diagnosis 17Patients booked for CT scan where this has yet to be done 4Patients where the CT identified matters of concern 12Including: Cancer 3

Aortic or Iliac aneurysm 3Ovarian cyst 2Requiring further test 1Pulmonary embolus 1Kidney stones 1Hiatus hernia 1

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Table 4. Rivaroxaban prescribing following VTE (May 2013 to April 2014)

Prescribing concerns identified 13Including a number of cases where drugs were stopped:

Strontium stoppedHormone-replacement-therapy stoppedAspirin stopped x 6 – haematuria in one caseRivaroxaban stopped after 3 weeks and 20 mg dose not commenced x 3Clopidogrel stopped x 2Rivaroxaban stopped due to poor renal function x1

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