A new risk prediction tool can identify patients at high risk of serious blood clots who might need preventative treatment, according to a study published in the British Medical Journal online. The tool, which can be found at www.qthrombosis.org, is based on simple variables which the patient is likely to know and could be easily integrated into GP computer systems to risk assess patients prior to hospital admission, long haul flights, or starting medications that carry an increased clotting risk.