Online Tool Identifies Blood Clot Risk

Predicting fatal blood clot risks without invasive hospital tests

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Most individuals have no idea whether they are at risk for a serious blood clot. A new online tool featuring simple questions patients can answer may help identify those in need of preventative treatment.

The tool can be found at, and provides a simple prediction of risk for a fatal blood clot without invasive hospital tests.

"Check your risk at"

University of Nottingham researchers designed the Web site to pinpoint those at risk of venous thromboembolism, a common and potentially lethal disease caused by a blockage or blood clot. In England, where the study was based, about 25,000 die each year, and about one third of those who survive have some sort of disability or long-term effects.

Development of the online tool was initiated by a 2010 call from the National Institute for Health and Clinical Excellence to identify high risk patients and utilize preventative measures.

Investigators used data from 563 general practices in England and Wales, studying more than 3.5 million patients between the ages of 25 and 84 without a history of blood clots. They then identified cases of venous thromboembolism, including deep vein thrombosis or pulmonary embolism, through patient medical records or death certificates, at one year and five years.

They found there were about 15 cases per 10,000 patients followed. The risk increased with age, body mass index and the number of cigarettes smoked daily. Risk was also increased among those who had varicose veins, congestive heart failure, chronic kidney disease, chronic lung disease, inflammatory bowel disease, and any form of cancer.

Those admitted to the hospital in the last six months or who took antipsychotic drugs, oral birth control or certain other drugs also were at an increased risk.

The online tool takes those risks into consideration before telling a patient whether they are at high risk, though the online tool is not meant to substitute for advice from a doctor.

Research about the online tool was published in journal BMJ.

Reviewed by: 
Review Date: 
August 19, 2011
Last Updated:
August 21, 2011