According to a study, checking patients' DNA before starting them on a popular blood thinner, warfarin, helps to get the dose right and prevents them from getting hospitalized.

The drug warfarin is sold as Coumadin in generic form. Each year, around 2 million Americans start it to avoid blood clots after surgery or for other medical conditions. However, the world's most common blood thinner is also one of the most perilous drugs. One person's ideal dose can be 10 times that of another's.

Also too much warfarin can cause bleeding, while too little can lead to clots, and either one can kill. In the initial six months on the drug, nearly 20% of patients end up being in the hospital.

On Tuesday, a new study, presented at an American College of Cardiology conference, recommends that patients who were given gene tests to set their first warfarin dose, had about a 30% lower risk of being hospitalized compared to patients whose doses were set by trial and error method.

Study Leader, Dr. Robert Epstein, who is Chief Medical Officer of Medco Health Solutions Inc., said, "If we reduce just two hospitalizations per 100 patients tested, that more than compensates for the cost". He said that demonstrations show that warfarin can work better with genetics. The newer drugs aiming to battle with warfarin must include gene testing for dose-setting to make a better comparison, he concluded.