Risk Assessment for VTE

Which of the following best describes you?

Which of the following best describes your institution?

Do surgical patients in your hospital receive thromboprophylaxis?

Do medical patients receive thromboprophylaxis in your hospital?

Which risk-assessment tool does your hospital use?

If used, is the risk-assessment tool:

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

Does your hospital provide extended- duration thromboprophylaxis?

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 PE 2 –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 –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 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

Risk Factors for VTE Patient characteristics Disease related Age Cancer/ cancer therapies Obesity Cardiac/respiratory failure Varicose veins Myocardial infarction Immobility Thrombophilia Paralysis of lower limb(s) Infection Pregnancy Inflammatory bowel disease Hormone therapy Nephrotic syndrome Previous VTE Polycythaemia Surgical therapy Trauma

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

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:

Endorse study Lancet 2008

Amended ACCP guidance Level of risk Approximate DVT risk without prophylaxis Suggested thromboprophylaxis LowMinor surgery in mobile patient Medical patients who are fully mobile <10%None Early ambulation ModerateMost general, open gynae or urologic surgery Medical patients bed rest or sick 10-40%LMWH LDUH Fondaparinux HighTHA, 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 Hospitals Consultant Haematologist