Select Committee on Health Written Evidence


Memorandum by Mr Alexander Cohen (VT9)


  Venous thromboembolism (VTE) consists of two related conditions: deep vein thrombosis (DVT) and pulmonary embolism (PE). In general, venous thrombosis is defined as a pathologic event in which a blood clot partially or totally occludes a vein. DVT usually occurs in the deep veins of the calf muscles and, less commonly, in the proximal (more central) deep veins of the leg and upper extremities.

  VTE is a potentially lethal disease with death most often occurring as a result of PE. Death can occur when the venous thrombi break off and form emboli, which pass to and obstruct the arteries of the lungs. Diagnosis of PE often occurs too late in the disease course to provide effective treatment. Most clinical studies report the incidence of DVT to be approximately twice that of PE1. VTE is a major public health problem and is both prevalent and costly2. Over half of all VTE is associated with recent hospitalisation with medical and surgical conditions having similar attributable risk (about one quarter each)2.

  Management of VTE comprises both prophylaxis and treatment of DVT and PE, plus management of the long-term sequelae of VTE, including post-thrombotic syndrome (PTS). Until recently, the majority of care was given in a secondary (hospital) setting, but long term secondary prevention is also managed by primary care physicians.


  Two approaches can be taken and these are described below.

  The available data from population based epidemiology studies can be used to calculate the burden and costing this problem. However, this incidence-based approach may not assess much of the burden from hospital costs in high risk groups who require preventive therapy, as it is based on reported events. VTE is notoriously inaccurately reported with rates as low as 30% being found in many studies. It also does not assess asymptomatic events which can have both short term and long term sequelae and costs

  It is also possible to do similar calculations using a "bottom up" approach. The "bottom up" approach examines hospital and community data, as well as assessing at risk populations and then annualises the current and future resource use for estimating the burden and cost. However the "bottom up" approach cannot estimate the burden of sudden death or undiagnosed mortality from this condition (in the absence of data from prospective cohorts or country specific autopsy data).

  We have recently undertaken a review of the burden and cost of venous thromboembolism using these two approaches to check the validity of each other, with the known limitation that they will measure different things. The results are presented below.


  The most robust European data come from the only two population based epidemiology studies from Nordstrom3 and Oger4 which have shown new (incident) DVT rates as 117 per 100,000 and 87 per 100,000 respectively (pooled estimate is 99 per 100,000 population). New (incident) PE rate was only reported in Oger4 and was 46 per 100,000. Lindblad and coworkers have shown in a population based autopsy study that autopsy diagnosed fatal PE occurs in around 40 per 100,000 population5. The original estimate of 40 fatal PEs per 100,000 (93 in 230,838 population) in the Linblad paper was based on an autopsy rate of 76.9%. Assuming 100% autopsy rate, fatal PEs rate was re-calculated as 52 per 100,000 population. Heit et al6)reported that 10.7% of the new PE cases would die within 14 days of hospitalisation, therefore these patients would already be counted as new non-fatal PEs. In order to avoid double counting, 10.7% of 52 per 100,000 were excluded, which gave the final estimate of sudden fatal PEs as 47 per 100,000 population.

  Therefore new cases of VTE has an estimated incidence of 145 per 100,000 diagnosed premortem and 47 per 100,000 diagnosed at post mortem in the developed world and hence is an important cause of morbidity and mortality3, 4, 5. One study reports that 11% of patients do not survive to one hour post PE event7. Initial treatment of DVT and PE is costly and patients who have DVT often develop serious long-term complications,8 which inevitably add to the cost burden on the Health Services9, 10.


  The hospital data model estimates approximately 49,000 expected annual cases of hospital acquired DVT and over 11,000 cases of Pulmonary Embolism. The community model estimates over 55,000 expected annual cases of community acquired DVT and over 20,000 cases of Pulmonary Embolism.

  The cost of illness (COI) model comprises two components, a community VTE algorithm and a hospital induced VTE algorithm. The hospital models annual costs for VTE management in the UK are estimated to be around £280 million. The community model costs are estimated at £360 million.

  The total cost burden (direct and indirect costs) to the UK of management of VTE is estimated at approximately £640 million. Approximately 60% of this total is attributable to community rather than hospital based incidence. Inpatient treatment costs account for almost 50% of the total cost burden and approximately 20% of costs are attributable to the chronic care costs of PTS.


DVTPE Total VTECost (£million)
UK Population59,000 27,000 diagnosed114,000 340
28,000 sudden death

DVTPE Total VTECost (£million)
Community55,00020,000 75,000360
Hospital49,00011,000 60,000280
Total UK Population104,000 31,000135,000640


  Whichever approach is taken it is clear that VTE is a major burden and cost to the UK and the NHS. The variation in figures reflects that the different approaches measure different things.

  VTE is a condition that is associated with medical and surgical settings and occurs in the community and hospitals. Most people are aware of travel related VTE, but the other associations, in particular hospitalisation are more common and require attention.

  The utilisation of appropriate and effective prevention (thromboprophylaxis) results in a reduction in the burden of 60-80% that would lead to major cost savings and, more importantly, a reduction in morbidity and mortality11-14.

November 2004

REFERENCES  1  White RH. The epidemiology of venous thromboembolism. Circulation 2003; 107(23 Suppl 1):I4-I8.

  2  Heit JA. Venous thromboembolism epidemiology: implications for prevention and management. Semin Thromb Hemost 2002; 28 Suppl 2:3-13.

  3  Nordstrom M, Lindblad B, Bergqvist D, Kjellstrom T. A prospective study of the incidence of deep-vein thrombosis within a defined urban population. J Intern Med 1992; 232(2):155-160.

  4  Oger E. Incidence of venous thromboembolism: a community-based study in Western France. EPI-GETBP Study Group. Groupe d'Etude de la Thrombose de Bretagne Occidentale. Thromb Haemost 2000; 83(5):657-660.

  5  Lindblad B, Sternby NH and Bergqvist D: Incidence of venous thromboembolism verified by necropsy over 30 years. BMJ, 1991; 302: 709-711.

  6  Heit JA, Silverstein MD, Mohr DN, Petterson TM, Lohse CM, O'Fallon WM et al. The epidemiology of venous thromboembolism in the community. Thromb Haemost 2001; 86(1):452-463.

  7  Kearon C. Natural history of venous thromboembolism. Circulation 2003; 107(23 Suppl 1):I22-I30.

  8  Heit JA. Risk factors for venous thromboembolism. Clin Chest Med 2003; 24(1):1-12.

  9  Bergqvist D, Jendteg S, Johansen L, Persson U, Odegaard K. Cost of Long-Term Complications of Deep Venous Thrombosis of the Lower Extremities: An Analysis of a Defined Patient Population in Sweden. Annals of Internal Medicine 1997; 126(6):454-457.

10  Cohen A, Botteman M, Stephens J, Ewing M, Collier P, Pashos C et al. Cost effectiveness of two anticoagulants for the prophylaxis of DVT and subsequent long-term complications (PTS and recurrent VTE) in total hip replacement surgery in the United Kingdom. Poster Presentation. XVIIIth Congress of the International Society on Thrombosis and Haemostasis, Paris, France. Thromb Haemost 2001; suppl—CD-ROM.

11  Geerts W et al Prevention of venous thromboembolism. Seventh ACCP Recommendations. Chest 2004; 126:338S-400S

12  Samama MM, Cohen AT, Darmon J-Y, et al. A comparison of enoxaparin with placebo for the prevention of venous thromboembolism in acutely ill medical patients. N Engl J Med 1999; 341: 793-800.

13  Cohen, AT, Davidson BL, Gallus AS, Lassen MR, Tomkowski W, Turpie AGG, Cariou, Egberts JFM, Lensing AWA. Fondaparinux for the Prevention of VTE in Acutely Ill Medical Patients. Blood 2003;102: Abstract number 42.

14  Cohen AT, Edmondson RA, Phillips MJ, Ward VP, Kakkar VV. The changing pattern of venous thromboembolic disease. Haemostasis 1996; 26: 65-71

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