DVT likely (Wells score 2 points or more)

1.1.3.

Offer people with a likely DVT Wells score (2 points or more):

• a proximal leg vein ultrasound scan, with the result available within 4 hours if possible (if the scan result cannot be obtained within 4 hours follow recommendation 1.1.4)
• a D-dimer test if the scan result is negative. [2012]

1.1.4.

If a proximal leg vein ultrasound scan result cannot be obtained within 4 hours, offer people with a DVT Wells score of 2 points or more:

• a D-dimer test, then
• interim therapeutic anticoagulation (see the section on interim therapeutic anticoagulation for suspected DVT or PE) and
• a proximal leg vein ultrasound scan with the result available within 24 hours. [2012, amended 2020]

1.1.5.

For people with a positive proximal leg vein ultrasound scan:

• offer or continue anticoagulation treatment (see the section on anticoagulation treatment for confirmed DVT or PE) or
• if anticoagulation treatment is contraindicated, offer a mechanical intervention (see the section on mechanical interventions).
  For people with symptomatic iliofemoral DVT, see the section on thrombolytic therapy. [2012]

1.1.6.

For people with a negative proximal leg vein ultrasound scan and a positive D-dimer test result:

• stop interim therapeutic anticoagulation, but do not stop:

  —

  long-term anticoagulation when used for secondary prevention [2012, amended 2020], or

  —

  short-term anticoagulation when used for primary venous thromboembolism (VTE) prevention in people with COVID-19 (see the recommendations on VTE prophylaxis in the NICE guideline on managing COVID-19) [2023]

• offer a repeat proximal leg vein ultrasound scan 6 to 8 days later and

  —

  if the repeat scan result is positive, follow the actions in recommendation 1.1.5 [2012, amended 2020]

  —

  if the repeat scan result is negative, follow the actions in recommendation 1.1.7. [2012, amended 2020]

1.1.7.

For people with a negative proximal leg vein ultrasound scan and a negative D-dimer test result:

• stop interim therapeutic anticoagulation, but do not stop:

  —

  long-term anticoagulation when used for secondary prevention [2012, amended 2020], or

  —

  short-term anticoagulation when used for primary VTE prevention in people with COVID-19 (see the recommendations on VTE prophylaxis in the NICE guideline on managing COVID-19) [2023]

• think about alternative diagnoses [2012, amended 2020]
• tell the person that it is not likely they have DVT. Discuss with them the signs and symptoms of DVT and when and where to seek further medical help. [2012, amended 2020]

DVT unlikely (Wells score 1 point or less)

1.1.8.

Offer people with an unlikely DVT Wells score (1 point or less):

• a D-dimer test with the result available within 4 hours (see the section on D-dimer testing) or
• if the D-dimer test result cannot be obtained within 4 hours, offer interim therapeutic anticoagulation while awaiting the result (see the section on interim therapeutic anticoagulation for suspected DVT or PE). [2012, amended 2020]

1.1.9.

If the D-dimer test result is negative, follow the actions in recommendation 1.1.7. [2012]

1.1.10.

If the D-dimer test result is positive, offer:

• a proximal leg vein ultrasound scan, with the result available within 4 hours if possible or
• interim therapeutic anticoagulation (see the section on interim therapeutic anticoagulation for suspected DVT or PE) and a proximal leg vein ultrasound scan with the result available within 24 hours. [2012, amended 2020]

1.1.11.

If the proximal leg vein ultrasound scan is:

• positive, follow the actions in recommendation 1.1.5 [2012]
• negative, follow the actions in recommendation 1.1.7, that is:

  —

  stop interim therapeutic anticoagulation, but do not stop:

  ◇

  long-term anticoagulation when used for secondary prevention [2012], or

  ◇

  short-term anticoagulation when used for primary VTE prevention in people with COVID-19 (see the recommendations on VTE prophylaxis in the NICE guideline on managing COVID-19) [2023]

  —

  think about alternative diagnoses [2012]

  —

  tell the person that it is not likely they have DVT. Discuss with them the signs and symptoms of DVT and when and where to seek further medical help. [2012]

D-dimer testing

1.1.12.

When offering D-dimer testing for suspected DVT or PE, consider a point-of-care test if laboratory facilities are not immediately available. [2020]

1.1.13.

If using a point-of-care D-dimer test, choose a fully quantitative test. [2020]

1.1.14.

When using a point-of-care or laboratory D-dimer test, consider an age-adjusted D-dimer test threshold for people aged over 50. [2020]

Pulmonary embolism rule-out criteria (the PERC rule)

1.1.16.

If clinical suspicion of PE is low based on the overall clinical impression (from general medical history, physical examination and any initial investigations such as electrocardiography or chest X-ray), and other diagnoses are feasible, consider using the pulmonary embolism rule-out criteria (PERC) to help determine whether any further investigations for PE are needed.

Be aware that the PERC rule has not been validated in people with COVID-19. [2020, amended 2023]

1.1.17.

If PE is suspected, use the 2-level PE Wells score (table 2) to estimate the clinical probability of PE. [2012]

Table 2

Two-level PE Wells score.

Adapted with permission from Wells et al. (2000) Derivation of a simple clinical model to categorize patients' probability of pulmonary embolism: increasing the model's utility with the SimpliRED D-dimer.

PE likely (Wells score more than 4 points)

1.1.18.

For people with a likely PE Wells score (more than 4 points):

• offer a computed tomography pulmonary angiogram (CTPA) immediately if possible or
• for people with an allergy to contrast media, severe renal impairment (estimated creatinine clearance less than 30 ml/min) or a high risk from irradiation, assess the suitability of a ventilation/perfusion single photon emission computed tomography (V/Q SPECT) scan or, if a V/Q SPECT scan is not available, a V/Q planar scan, as an alternative to CTPA.
  If a CTPA, V/Q SPECT or V/Q planar scan cannot be done immediately, offer interim therapeutic anticoagulation (see the section on interim therapeutic anticoagulation for suspected DVT or PE). [2012, amended 2020]

1.1.19.

If PE is identified by CTPA, V/Q SPECT or V/Q planar scan:

• offer or continue anticoagulation treatment (see the section on anticoagulation treatment for confirmed DVT or PE) or
• if anticoagulation treatment is contraindicated, consider a mechanical intervention (see the section on mechanical interventions).
  For people with PE and haemodynamic instability, see the section on thrombolytic therapy. [2012, amended 2020]

1.1.20.

If PE is not identified by CTPA, V/Q SPECT or V/Q planar scan:

• consider a proximal leg vein ultrasound scan if DVT is suspected [2012, amended 2020]
• if DVT is not suspected:

  —

  stop interim therapeutic anticoagulation, but do not stop:

  ◇

  long-term anticoagulation when used for secondary prevention [2012, amended 2020], or

  ◇

  short-term anticoagulation when used for primary VTE prevention in people with COVID-19 (see the recommendations on VTE prophylaxis in the NICE guideline on managing COVID-19) [2023]

  —

  think about alternative diagnoses [2012, amended 2020]

  —

  tell the person that it is not likely they have PE. Discuss with them the signs and symptoms of PE and when and where to seek further medical help. [2012, amended 2020]

PE unlikely (Wells score 4 points or less)

1.1.21.

Offer people with an unlikely PE Wells score (4 points or less):

• a D-dimer test with the result available within 4 hours if possible (see the section on D-dimer testing) [2012, amended 2020] or
• if the D-dimer test result cannot be obtained within 4 hours (in any setting), offer interim therapeutic anticoagulation while awaiting the result (see the section on interim therapeutic anticoagulation for suspected DVT or PE). [2012, amended 2020]
  If the D-dimer test result is:
• positive, follow the actions in recommendations 1.1.18 and 1.1.19 [2012, amended 2020]
• negative:

  —

  stop interim therapeutic anticoagulation, but do not stop:

  ◇

  long-term anticoagulation when used for secondary prevention [2012, amended 2020], or

  ◇

  short-term anticoagulation when used for primary VTE prevention in people with COVID-19 (see the recommendations on VTE prophylaxis in the NICE guideline on managing COVID-19) [2023]

  —

  think about alternative diagnoses [2012, amended 2020]

  —

  tell the person that it is not likely they have PE. Discuss with them the signs and symptoms of PE and when and where to seek further medical help. [2012, amended 2020]

Anticoagulation treatment for DVT or PE in people at extremes of body weight

1.3.11.

Consider anticoagulation treatment with regular monitoring of therapeutic levels for people with confirmed proximal DVT or PE who weigh less than 50 kg or more than 120 kg, to ensure effective anticoagulation.

Note the cautions and requirements for dose adjustment and monitoring in the medicine's summary of product characteristics (SPC), and follow locally agreed protocols or advice from a specialist or multidisciplinary team. [2020]

Anticoagulation treatment for PE with haemodynamic instability

1.3.12.

For people with confirmed PE and haemodynamic instability, offer continuous UFH infusion and consider thrombolytic therapy (see the section on thrombolytic therapy). [2020]

Anticoagulation treatment for DVT or PE with renal impairment or established renal failure

1.3.13.

Offer people with confirmed proximal DVT or PE and renal impairment (estimated creatinine clearance between 15 ml/min and 50 ml/min) one of:

• apixaban
• rivaroxaban
• LMWH for at least 5 days followed by:

  —

  edoxaban or

  —

  dabigatran if estimated creatinine clearance is 30 ml/min or above

• LMWH or UFH, given concurrently with a VKA for at least 5 days or until the INR is at least 2.0 in 2 consecutive readings, followed by a VKA on its own.
  Note the cautions and requirements for dose adjustment and monitoring in the medicine's SPC, and follow locally agreed protocols or advice from a specialist or multidisciplinary team. [2020]

1.3.14.

Offer people with confirmed proximal DVT or PE and established renal failure (estimated creatinine clearance less than 15 ml/min) one of:

• LMWH
• UFH
• LMWH or UFH concurrently with a VKA for at least 5 days or until the INR is at least 2.0 in 2 consecutive readings, followed by a VKA on its own.
  Note the cautions and requirements for dose adjustment and monitoring in the medicine's SPC, and follow locally agreed protocols or advice from a specialist or multidisciplinary team. [2020]

Anticoagulation treatment for DVT or PE with active cancer

1.3.15.

Offer people with active cancer and confirmed proximal DVT or PE anticoagulation treatment for 3 to 6 months. Review at 3 to 6 months according to clinical need. For recommendations on treatment after 3 to 6 months, see the section on long-term anticoagulation for secondary prevention. [2020]

1.3.16.

When choosing anticoagulation treatment for people with active cancer and confirmed proximal DVT or PE, take into account the tumour site, interactions with other drugs including those used to treat cancer, and the person's bleeding risk. [2020]

1.3.17.

Consider a direct-acting oral anticoagulant (DOAC) for people with active cancer and confirmed proximal DVT or PE. [2020]

1.3.18.

If a DOAC is unsuitable consider LMWH alone or LMWH concurrently with a VKA for at least 5 days, or until the INR is at least 2.0 in 2 consecutive readings, followed by a VKA on its own. [2020]

1.3.19.

For people with confirmed DVT or PE and cancer that is in remission, follow the recommendations in the section on anticoagulation treatment for confirmed DVT or PE. [2020]

Anticoagulation treatment for DVT or PE with triple positive antiphospholipid syndrome

1.3.20.

Offer people with confirmed proximal DVT or PE and an established diagnosis of triple positive antiphospholipid syndrome LMWH concurrently with a VKA for at least 5 days, or until the INR is at least 2.0 in 2 consecutive readings, followed by a VKA on its own. [2020]

Point-of-care D-dimer testing

The committee agreed that, if both laboratory-based and point-of-care D-dimer testing are immediately available, laboratory testing is preferable because it provides more rigorous quality assurance and greater certainty of diagnostic accuracy. However, if laboratory-based testing is not immediately available, the committee were in agreement that offering immediate point-of-care testing is more beneficial for patients than delaying diagnosis by waiting for laboratory testing. Although point-of-care tests are more expensive than laboratory tests, a cost-effectiveness analysis showed that the additional cost may be offset by faster results that reduce the need for additional GP time and unnecessary interim anticoagulation.

Evidence on fully quantitative point-of-care D-dimer tests for DVT suggested that they are as accurate as laboratory tests and more accurate than qualitative or semi-quantitative tests. There is little evidence on these tests for PE but the committee agreed that the evidence on DVT is applicable to PE because it is very unlikely that there is a biological reason that the accuracy of the tests would differ between these groups. The committee were aware that quantitative tests are more commonly used than qualitative or semiquantitative tests. However, because the latter types of tests are still used in some services, they specified that point-of-care tests should be fully quantitative.

Age-adjusted D-dimer test thresholds

In people aged over 50, there was limited prospective evidence available for DVT and only retrospective evidence available for PE. This evidence suggested that adjusting D-dimer test thresholds for age improves the usefulness of these tests for ruling out VTE in this age group. The evidence also suggested that age adjustment does not reduce the accuracy of the tests in identifying VTE. The committee noted that adjusting test thresholds for age could be beneficial in reducing anxiety and unnecessary imaging for people with suspected DVT or PE. Although the evidence was not plentiful, the committee agreed that, taken together with the potential benefits, it was sufficient to support a recommendation suggesting age adjustment in D-dimer test thresholds for people aged over 50.

Interim therapeutic anticoagulation for suspected DVT or PE

There was no evidence specifically on interim anticoagulation treatment for suspected DVT or PE. However, the committee agreed that it is vital to start treatment if DVT or PE is suspected and diagnostic test results are delayed by more than 4 hours. They reasoned that anticoagulation treatments that are effective for confirmed DVT or PE are likely to be equally effective when used as interim treatment while awaiting a confirmed diagnosis. They also noted that continuing the same anticoagulant treatment after diagnosis offers benefits in terms of safety and convenience. However, they acknowledged that local protocols or availability of anticoagulants for suspected VTE may necessitate the use of different anticoagulants before and after diagnosis.

The committee agreed that when choosing an interim anticoagulant, clinicians should always take individual clinical circumstances into account, including whether the person is at an extreme of body weight, has PE with haemodynamic instability, renal impairment, active cancer or established triple positive antiphospholipid syndrome.

Anticoagulation treatment for confirmed DVT or PE

Evidence suggested that treatment with a direct-acting oral anticoagulant (DOAC) is less likely to result in bleeding complications than treatment with low molecular weight heparin (LMWH) and a vitamin K antagonist (VKA). Additionally, people taking a DOAC benefit by being able to have an oral treatment and avoid the frequent monitoring that is necessary with other types of anticoagulation treatment.

Within the DOACs, there was evidence showing that apixaban is the most cost-effective option. because it results in the fewest bleeds. Rivaroxaban is the second most cost-effective option and only slightly less cost effective than apixaban. However, the committee had reservations about this evidence because the inclusion criteria setting out which patients took part in the studies were not the same in each study. In particular, the apixaban study did not include patients with provoked VTE unless it was caused by a persistent risk factor, so a larger proportion of patients in the apixaban study had unprovoked VTE compared with the rivaroxaban studies. This made it difficult to compare the results of the studies. Because of this, the committee were not confident that apixaban should be the only option for a DOAC and recommended a choice of apixaban or rivaroxaban. Sensitivity analyses were carried out varying the drug prices but these analyses did not change any of the conclusions from the economic model.

The committee recognised that apixaban or rivaroxaban might not be suitable for everyone, so they included options for treatment with LMWH followed by dabigatran or edoxaban, or LMWH with a VKA. The committee also made a recommendation for research on DOACs compared with each other and with other anticoagulants.

The evidence did not support a recommendation for fondaparinux. It showed that fondaparinux is more likely to result in bleeding and is less cost effective than other treatments. However, the committee decided not to make a recommendation precluding its use because they were aware that it may be needed in rare circumstances.

Unfractionated heparin (UFH) was associated with increased bleeding complications, greater recurrence rates of VTE and higher mortality rates than other treatments so the committee did not think it should be offered routinely. They recognised that it may be a suitable option for some people with VTE.

Anticoagulation treatment for DVT or PE in people at extremes of body weight (less than 50 kg or more than 120 kg)

Body weight can influence the absorption, distribution and elimination of anticoagulants, and their therapeutic effect can be altered at extremes of body weight. Because of this, and based on their knowledge and experience, the committee agreed that body weight should be taken into account and therapeutic monitoring considered when choosing anticoagulation for people whose weight is outside the range of 50 kg to 120 kg.

There was little evidence on the comparative effectiveness of different anticoagulants for people at extremes of body weight, and the evidence was limited to obesity defined as a body mass index of 30 kg/m² and above rather than body weight. However, the committee noted that the summaries of product characteristics (SPCs) for several anticoagulants specify body weight rather than obesity and agreed that using the same criterion as the SPCs would make the recommendations clearer and easier to implement.

Because of the uncertainty about the most effective anticoagulant treatment for this group, the committee included a subgroup based on body weight in their recommendation for research on DOACs compared with each other and with other anticoagulants.

Anticoagulation treatment for PE with haemodynamic instability

The committee agreed that intravenous UFH should be offered to people with PE and haemodynamic instability because the anticoagulant effect needs to be carefully controlled for these people. People with haemodynamic instability have poor peripheral circulation and because UFH is administered intravenously it allows for a more certain therapeutic effect. Additionally, the anticoagulant effect of UFH wears off relatively quickly if treatment needs to be stopped.

The committee did not review the evidence on thrombolytic therapy and the 2012 recommendation that it be considered for this population is unchanged.

Anticoagulation treatment for DVT or PE with renal impairment or established renal failure

Renal impairment increases the risk of anticoagulants accumulating in the body, which can increase bleeding risk. There was very limited evidence on anticoagulant treatment for VTE in people with renal impairment.

Based on their expertise and the SPC for each treatment, the committee agreed that LMWH, UFH or DOACs are suitable options to treat VTE in people with renal impairment. However, dabigatran is not an option for people with more severe renal impairment (estimated creatinine clearance 15 ml/min to 29 ml/min) based on its SPC. For people with estimated creatinine clearance less than 15 ml/min the main options are UFH or LMWH given either on their own or with a VKA until oral anticoagulation is established and in the therapeutic range. The committee emphasised the importance of following the SPCs and locally agreed protocols, and seeking advice from specialist colleagues or a multidisciplinary team to ensure correct dosing and monitoring.

Anticoagulation treatment for DVT or PE with active cancer

There was very little evidence available on the duration of anticoagulation treatment for people with DVT or PE and active cancer. The committee agreed, based on the evidence and their experience, that anticoagulation treatment should continue for 3 to 6 months and then be reviewed. They noted that most of the evidence on VTE in people with active cancer looked at treatment over a period of 6 months, but agreed that some people need shorter treatment durations and it is good practice to determine the length of treatment on a case-by-case basis.

The effectiveness of DOACs compared with other anticoagulation treatments in people with active cancer has not been studied sufficiently to enable firm conclusions to be made. Evidence from studies in people without cancer may not be applicable because cancer could affect the action of these drugs. In studies that recruited only people with active cancer and VTE, rivaroxaban, edoxaban and LMWH were found to be similarly effective, although bleeding complications were more frequent with DOACs. These studies did not look at apixaban or dabigatran. In studies that looked at apixaban and dabigatran and in which a small number of people within the study population had active cancer, the effects of apixaban and dabigatran were similar in people with and without cancer. Economic evidence based on these studies showed apixaban to be the most cost-effective option, although the evidence for apixaban was based on a relatively small number of people.

The committee agreed that, if suitable, a DOAC should be considered to treat VTE in people with active cancer but, because of the limitations of the evidence, they could not be more specific about the choice of DOAC.

The committee noted the potential for interactions between anticoagulants and other drugs people with active cancer may be taking, such as chemotherapy drugs, and the possibility of an increased risk of bleeding with some types of tumours. The evidence suggested a higher rate of gastrointestinal and genitourinary bleeds in people with active cancer having treatment with a DOAC compared with those having LMWH. The committee agreed that DOACs may be unsuitable for people with tumours that are associated with an increased risk of these types of bleeds (such as people with gastrointestinal malignancies). However, they agreed that treatment decisions for people with active cancer need to be made on a case-by-case basis.

The committee made provision for people with active cancer if a DOAC is not suitable by including LMWH alone and LMWH with a VKA as alternatives. Although LMWH alone is commonly used in practice and is the only licensed option to treat VTE in active cancer, it is not cost effective compared with DOACs and reducing its use would be beneficial in conserving NHS resources. Sensitivity analyses were carried out varying the drug prices but these analyses did not change any of the conclusions from the economic model.

The committee recognised that there are circumstances in which LMWH is the most suitable treatment option and agreed that it could be considered when this is the case. They were aware that LMWH with a VKA is often impractical for people with active cancer because of difficulties with international normalised ratio (INR) monitoring and maintaining INR within the therapeutic range. They agreed that it is less clinically effective than LMWH alone but is less costly and remains a suitable option in some circumstances.

Anticoagulation treatment for people with DVT or PE and triple positive antiphospholipid syndrome

The committee were aware of an MHRA safety alert warning of an increase in VTE recurrence in people with diagnosed triple positive antiphospholipid syndrome taking a DOAC compared with those taking LMWH and a VKA. Although people with antiphospholipid syndrome were not included in the evidence review, the committee agreed that it is important to include a recommendation highlighting the need to offer LMWH with a VKA to this group.

Anticoagulation treatment for DVT or PE in people who use intravenous drugs

VTE can be difficult to treat in people who use intravenous drugs. They often have problems with access to medical care and adherence to prescribed treatments. There is a lack of good evidence on the comparative clinical and cost effectiveness of treatments and doses for VTE in this population. The committee made a recommendation for research with the aim of improving VTE treatment in people who use intravenous drugs.

Treatment failure

The committee acknowledged that VTE can recur despite anticoagulant treatment and used their knowledge and experience to outline steps that can be taken if treatment fails.

Predicting VTE recurrence and assessing bleeding risk after provoked or unprovoked DVT or PE

The committee noted that continuing anticoagulation treatment after 3 months is less beneficial for people who have had a provoked DVT or PE if the provoking factor is no longer present, because of the lower rate of recurrence compared with unprovoked DVT or PE.

For people with unprovoked DVT or PE, the benefits and risks of continuing anticoagulation treatment are less certain and the committee agreed that they need to be carefully balanced. However, for most people with a low bleeding risk, the committee agreed that the benefits of continuing anticoagulation treatment outweigh the risks.

The committee agreed that the tools currently available to predict the risk of recurrence of VTE or the risk of bleeding are not sufficiently accurate or validated to be used as the sole basis for a decision, and that using them in such a manner might result in incorrect predictions and subsequent harm to the person. However, they also agreed that, in certain circumstances, a clinical prediction tool can be a useful adjunct to discussion with people offered long-term anticoagulation treatment. For bleeding risk, evidence on the HAS-BLED score showed that it can identify people with unprovoked proximal DVT or PE who are at particularly high risk of major bleeding and might benefit from stopping anticoagulation. For VTE recurrence, there was very limited evidence, and that evidence suggested that these tools are not sufficiently accurate to be used in practice.

Because of the uncertainty in predicting VTE recurrence and the risk of major bleeding, the committee made recommendations for research to develop a new prediction tool for VTE recurrence and major bleeding combined and research to compare this tool with clinical judgement.

Continuing or changing current treatment

The committee agreed that there are risks involved in switching anticoagulant treatment, particularly if there have been no adverse events with the current treatment. They also expressed concerns about convenience for people who are asked to switch from a DOAC with no monitoring to a VKA regimen with frequent monitoring, or problems with adherence if switching from a VKA to a DOAC. Based on these concerns and their clinical experience, the committee agreed that if treatment is continued beyond 3 months, the first option for most people should be to continue the current treatment if it is well tolerated.

Some evidence indicated that there are fewer major bleeds with apixaban than with rivaroxaban, dabigatran or a VKA. However, the committee were not entirely convinced by this evidence because the study of apixaban had stricter inclusion criteria, setting out which patients took part, than the other studies. Additionally, the studies recorded a very low number of major bleeds, leading to uncertainty about the effects of the different anticoagulation treatments on the likelihood of major bleeding. Apixaban was shown by the economic evidence to be the most cost-effective long-term treatment so the committee agreed that switching to apixaban should be considered as an option for people currently taking a DOAC other than apixaban. Sensitivity analyses were carried out varying the drug prices but these analyses did not change any of the conclusions from the economic model.

There was a lack of evidence on longer-term treatment for people with renal impairment, active cancer, antiphospholipid syndrome or extremes of body weight. Based on their clinical experience, the committee agreed that continuing the current treatment, if it is well tolerated, should be considered for people in these groups, taking into account their preferences and clinical situation.

For people who do not continue anticoagulation treatment, evidence showed that aspirin is better than no treatment at reducing DVT or PE recurrence for up to 2 years, although there was no difference in DVT or PE recurrence between aspirin and no treatment at 4 years. On balance, the committee agreed that aspirin can be considered as an option for people who wish to stop anticoagulation treatment, using a prophylactic dose based on current UK practice (75 mg daily or 150 mg daily).

To ensure that treatment is guided by the person's changing balance of benefits and risks, and changes in their preferences over time, the committee agreed that people taking long-term anticoagulation treatment or aspirin should have their risk of VTE recurrence, bleeding risk and general health reviewed at least once a year.