Details of HTA project
Last updated: 15 July 2008 - Next update due: 22 July 2008
Research type: |
NICE Technology Assessment Report (TAR) |
Project title: |
Thrombophilia testing |
Project ref: |
06/66/01 |
Cost: |
This project has been commissioned by the HTA programme on behalf of the National Institute for Health and Clinical Excellence on a call-off contract basis. |
Chief Investigator : |
School of Health and Related Research (ScHARR-TAG), University of Sheffield |
Start Date: |
September 2006. |
Publication date: |
November 2008. This project is at the editorial review stage. Delays in the review process can cause the forecast publication date to be delayed. |
Plain English Summary |
Arterial and venous thrombophilias are acquired or inherited (genetic) defects in blood coagulation that lead to a predisposition towards arterial or venous thrombosis. A thrombus is a solid mass of blood constituents that can fragment and block vessels downstream (thromboembolism). Depending on the blood vessel occluded, arterial thromboemoboli can lead to coronary artery thrombosis (myocardial infarction) or stroke, and venous thromboemboli can lead to pulmonary embolism, or rarely, stroke. Venous thrombosis often occurs in normal vessels, with the majority of venous thrombi forming in the deep veins of the leg (deep vein thrombosis, DVT). Venous thrombosis is an important cause of morbidity and mortality; approximately 90% of pulmonary emboli are caused by dislodged fragments from asymptomatic DVTs. The estimated annual incidence of venous thrombosis is 1 in 1000 individuals in the general population. Arterial thrombosis usually occurs in association with atheroma in areas of turbulent blood flow, such as the bifurcation of arteries. Inherited (genetic) thrombophilia is caused most commonly by mutations in genes for coagulation factors II and V. Acquired thrombophilia refers to conditions in which individuals without genetic defects in coagulation factors are at increased risk of thrombosis, for example pregnancy, oestrogen therapy from combined oral contraceptives or hormone replacement therapy, obesity, fractures and major orthopaedic surgery. |
Abstract: |
Objective: To appraise the clinical and cost effectiveness of thrombophilia testing in patients with venous thrombotic events, and in patients with arterial thrombotic events, and to provide guidance to the NHS in England and Wales. The appraisal will consider the extent to which a diagnosis of thrombophilia influences the intensity or duration of anticoagulant therapy, and the subsequent impact on outcome. Intervention: Thrombophilia testing refers to a panel of tests which are performed on individuals who are believed to be at high risk of thrombosis, the purpose being to identify those who may benefit from a more intensive or prolonged course of anticoagulant therapy and to prevent thrombosis. A blood sample is taken and a panel of diagnostic tests are performed to detect deficiencies in blood coagulation. Diagnostic tests that may be predictive for an increased risk of venous thrombosis include tests for factor V Leiden, prothrombin G20210A, assays of clotting factors and the physiological anticoagulants antithrombin, protein C and protein S. Diagnostic tests that may be predictive for an increased risk of arterial thrombosis include assays of homocysteine and antiphospholipid antibodies. The intervention for this review will be thrombophilia tests performed on individuals with thrombosis, with the resulting anticoagulation management. Comparator: The comparator for this review will be individuals with thrombosis who are not subject to thrombophilia testing, and their anticoagulation management. Population: Two populations will be considered separately: 1. Individuals with venous thrombosis; 2. Individuals with arterial thrombosis. The following subgroups will be considered: smoking status; sex; age at first event; site of first thrombosis. For the intervention group, the population will be grouped according to whether tested after first event or recurrent thrombosis. Key factors to be addressed: The review aims to discover whether anticoagulation management and subsequent thrombotic event rates are altered in the light of thrombophilia test results. The review will also investigate adverse events resulting from anticoagulation management, specifically rates of haemorrhage, and affect on health-related quality of life. Areas outside the scope of this appraisal: Screening of individuals exposed to conditions which increase the susceptibility to acquired thrombophilia (for example major orthopaedic surgery and pregnancy) has been excluded from the scope of this appraisal. Case finding by testing of asymptomatic individuals with a family history of thrombophilia or thrombosis, but no personal history of thrombosis, is outside the scope of this review. These are important issues but it has been agreed that it is not feasible to appraise all these within a single technology assessment report. The HTA Programme commissioned this technology assessment report on behalf of the National Institute for Health and Clinical Excellence. |
MeSH* index primary terms: |
THROMBOPHILIA Q-diagnosis; THROMBOPHILIA Q-economics |
MeSH* index secondary terms: |
HUMANS; COST-BENEFIT-ANALYSIS; ENGLAND; WALES |
NRR* number, if applicable: |
N0484189156 (*National Research Register) |
Project Protocol: |
Project protocol not available |
URL of this page: |
http://www.hta.ac.uk/1552 |
News feeds