Half of all hospital patients at clot risk: study

By Michael Kahn

LONDON (Reuters) - More than half of all hospital patients are at risk of blood clots but many do not receive simple treatment that could prevent them, British researchers said on Thursday.

The study published in the journal Lancet looked at more than 68,000 patients at 358 hospitals in 32 countries and found that people who had undergone surgery were most likely to develop venous thromboembolism, or blood clots.

"The data show that, worldwide, more than half of all hospitalized patients are at risk for venous thromboembolism and that surgical patients seem to be at higher risk than medical patients," Ander Cohen of King's College London and Ajay Kakkar at Barts and The London School of Medicine and Dentistry wrote.

The condition includes deep vein thrombosis or blood clots in the legs, and pulmonary embolism, which most commonly occurs when the blood clot dislodges to the lungs. Such clots account for an estimated 10 percent of all in-hospital patient deaths.

People having surgery and receiving medical treatment for fractures or illnesses such as cancer are at high risk of clots if they have poor circulation or are immobile for long periods. Obesity and family history are other risk factors.

Blood-thinning drugs or special stockings to improve blood flow can help prevent the condition but the researchers said half of the high-risk people in the study did not receive preventative treatment.

"The real conclusion you draw from this is there are very few complications that affect people in hospitals as much as blood clots," Kakkar said in a telephone interview. "The risk factors are very common."

The researchers first determined which patients in the study were at highest risk and then checked to see if doctors had recommended any preventative measures set out in internationally accepted guidelines.

The study also showed that a country's economic status did not seem to be an indicator of how well hospitals identified and treated patients at greatest risk of blood clots.

For example, in surgical patients, the best performing countries were Germany, Hungary and Spain where more than 82 percent of people at highest risk got some kind of preventative treatment. The proportion in the United States and Britain was 71 percent and 74 percent, respectively.

At the low end were Bangladesh and Thailand where 0.2 percent of high risk patients received preventative treatment followed by Pakistan at 10 percent.

"Work is needed to improve prevention of venous thromboembolism in hospitalized patients," Walter Ageno and Frencesco Dentali of the University of Insubria in Varese, Italy, wrote in a Lancet commentary.

(Reporting by Michael Kahn, Editing by Maggie Fox)