Risk Assessment for VTE

Which of the following best describes you?

5

15

2

28

8

6

29

1. Physician

2. Haematologist

3. Surgeon

4. Nurse

5. Pharmacist

6. Health service manager /commissioner

7. Other

Which of the following best describes your institution?

35

23

0

1

4

10

1. Teaching hospital

2. District general hospital

3. Primary care practice

4. Primary care management (PCT)

5. Private hospital

6. Other

Do surgical patients in your hospital receive thromboprophylaxis?

59

5

1

0

1. Regularly

2. Occasionally

3. Rarely

4. Never

Do medical patients receive thromboprophylaxis in your hospital?

34

24

6

2

1. Regularly

2. Occasionally

3. Rarely

4. Never

Which risk-assessment tool does your hospital use?

10

1

39

4

0

4

4

1. Surgical-specific only

2. Medical-specific only

3. Medical- and surgical-specific

4. Unified

5. CMO tool published in September 2008

6. None

7. Don’t know

If used, is the risk-assessment tool:

39

15

3

1. Opt in (must fulfil specific criteria in order to be prescribed prophylaxis)?

2. Opt out (all given chemical prophylaxis unless contraindicated)?

3. Other

Which of the following are used for thromboprophylaxis in your hospital?

0

0

1

0

0

0

0

0

1. Anti-embolism stockings

2. Intermittent pneumatic compression

3. Low molecular weight heparin

4. Unfractionated heparin

5. Warfarin

6. Aspirin

7. Fondaparinux

8. New oral agent

Does your hospital provide extended-duration thromboprophylaxis?

19

33

4

6

1. Routinely

2. Occasionally

3. Rarely

4. Never

Risk assessment for VTE

• Risk

• Risk assessment

• Thromboprophylaxis risk assessment strategies

Risk assessment for VTE

• Risk

• Risk assessment

• Thromboprophylaxis risk assessment strategies

What is risk?

Risk can be defined as the probability of an unwanted event occurring and the severity of potential loss

Risks exist because things considered to have value are placed at risk

Risk assessment for VTE

• Risk

• Risk assessment

• Thromboprophylaxis risk assessment strategies

What is Risk Assessment?

• Risk assessment consists of an objective evaluation of risk in which assumptions and uncertainties are clearly considered and presented.

• Part of the difficulty of risk management is that the measurement of the quantities in which risk assessment is concerned - potential loss and probability of occurrence - can be very difficult to measure.

Wikipedia

Risk Assessment for VTE

• Potential losses:– Morbidity or mortality from VTE

(including complications of therapy)– Financial cost of investigating and

treating VTE– Increased future risk of VTE

• Probability of occurrence:– Likelihood of patient developing VTE

Potential Losses from VTE• Morbidity

– Post thrombotic syndrome in 30%, severe in 3-5%1 – Chronic thromboembolic pulmonary hypertension in 4-8% of patients

following PE2

– Bleeding from anticoagulant therapies (1% major bleeding)

• Mortality– 25,000 patients each year are thought to die of VTE in UK hospitals– Mortality from DVT 1-6%– Mortality from PE 10-30– Mortality from anticoagulant therapies (0.3%/year)

• Costs to healthcare system– Investigation and treatment of thrombotic episode– Prolongation of inpatient stay– Treatment of long term complications

1 Khan SR et al. Ann Int Med 20082 Dentali F et al. Thr Res Feb 2009

Probability of occurrence of VTE in hospitalised patients

From ACCP Guidelines on prevention VTE Chest 2008

Most VTE cases are not detected

20%symptomatic

80%asymptomatic

Likelihood of symptomatic VTE in hospitalised patients

0

1

2

3

4

5

6

7

8

9

10

medical low moderate high very high

proximal DVT

clinical PE

fatal PE

Risk Factors for VTE

Patient characteristics

Disease related

Age

Cancer/ cancer therapiesObesity

Cardiac/respiratory failureVaricose veins

Myocardial infarctionImmobility

Thrombophilia Paralysis of lower limb(s)Infection

Pregnancy

Inflammatory bowel diseaseHormone therapy

Nephrotic syndromePrevious VTE

Polycythaemia

Surgical therapyTrauma

Proportion of hospital inpatients at risk of VTE

Endorse study Lancet 2008

Thromboprophylaxis strategies are required

• It is, as yet, impossible to identify those individuals who will develop VTE

• Screening using imaging techniques is of low sensitivity, expensive, time consuming

• Asymptomatic DVT can cause fatal PE

Potential losses: risk of intervention

• Adverse effects of prophylactic therapies– Bleeding

• Dependent on surgical procedure• Intracerebral haemorrhage/ GI bleeding

– Heparin Induced Thrombocytopenia• Dependent on prophylactic agent chosen• Higher with unfractionated heparin

• Costs to healthcare system of adverse events

Risk assessment for VTE

• Risk

• Risk assessment

• Thromboprophylaxis risk assessment strategies

Why Risk Assessment for VTE?

Objectives of RAM

Reduce the burden of VTE

Cost containment

Improve the use of appropriate

thromboprophylaxis

Identify patients at significant risk of

VTE

Simplify decision making

Cohen AT et al. J Thromb Haemost 2003;1 (Suppl 1):OC437

Thromboprophylaxis Risk Assessment Strategies

• Opt-in– Surgical only– Medical only– Hybrid models

• Opt-out

• Electronic risk assessment (opt in or opt out)

Autar risk assessment

Sheffield surgical risk assessment

Hunt BJH March 2009

Hunt BJH March 2009

Opt-out model

• Little evidence base

• Advantages– Patients at risk of VTE possibly more likely to

receive thromboprophylaxis

• Disadvantages– Patients not at risk will receive prophylaxis– Patients are likely to be given prophylaxis even

if at increased risk of side-effects

Information Technology helps

Kucher, N. et al. N Engl J Med 2005;352:969-977

Endorse study Lancet 2008

Amended ACCP guidance

Level of risk

Approximate DVT risk without prophylaxis

Suggested thromboprophylaxis

Low Minor surgery in mobile patient

Medical patients who are fully mobile

<10% None

Early ambulation

Moderate Most general, open gynae or urologic surgery

Medical patients bed rest or sick

10-40% LMWH

LDUH

Fondaparinux

High THA, TKA, hip fracture, major trauma, SCI

40-80% LMWH, fondaparinux, oral vit K antagonist

Geerts et al, ACCP, Chest 2008

• We recommend the use of strategies shown to increase thromboprophylaxis adherence, including the use of computer decision support systems, preprinted orders, and periodic audit and feedback.

• Passive methods such as distribution of educational materials or educational meetings are not recommended as sole strategies to increase adherence to thromboprophylaxis

Risk assessment for VTE

• Identify patients who would benefit from thromboprophylaxis

• Strategy chosen will be dependent on– Culture of organisation– Local opinion– Information Technology

• For strategy to work- needs to be simple

Rhona Maclean

Sheffield Teaching HospitalsConsultant Haematologist

Rhona.maclean@sth.nhs.uk