Factor V Leiden & Prothrombin G20210A, Outcomes from Testing

Full Title: Outcomes from Testing for Factor V Leiden and Prothrombin G20210A

Expected Release Date: mid 2009

Key Questions (KQ)*

• KQ1a: What is the evidence regarding the reproducibility of existing diagnostic tests for the Factor V Leiden (FVL) mutation and the prothrombin G20210A mutation, as well as their analytic sensitivity and specificity, and robustness (sources of variability)?
• KQ2a: What is the evidence that the presence of FVL alone or prothrombin G20210A alone or the two in combination predicts risk of recurrent venous thromboembolism (VTE) in individuals (probands) who have had VTE and predicts the risk of VTE in the probands' family members? Does the testing add predictive information beyond clinical data?
• KQ2b: What is the evidence that demographic or clinical factors modify the relationship between the presence of FVL or prothrombin G20210A and the risk of VTE?
• KQ3a: What is the evidence that clinicians manage patients differently based on the results of testing for FVL or prothrombin G20210A? How do clinicians manage anticoagulation of individuals who have had testing compared to those who have not had testing? What other diagnostic tests do clinicians order or not order based on testing results? What recommendations do clinicians make regarding other therapies and exposures based on testing results?
• KQ3b: What is the evidence that testing, and the resultant management, reduces VTE related-outcomes or has other benefits in individuals who have had VTE or in the probands' family members?
• KQ3c: What is the evidence of harms to individuals with VTE or to the probands' family members as a result of testing for FVL or prothrombin G20210 or as a result of changed management based on the test results?
• KQ3d: What is the evidence that testing for FVL alone, prothrombin G20210 alone, or the two tests in combination is a cost-effective strategy when caring for a patient with VTE or a family member of a proband?

*To be addressed in evidence report.

Current as of April 2008

Internet Citation:

Outcomes from Testing for Factor V Leiden and Prothrombin G20210A, Clinical Focus. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/clinic/tp/fvltp.htm