Older adults who had stayed in nursing homes or hospitals and developed infections of any kind—such as urinary, skin or respiratory tract infections—are seven times more likely to be hospitalized for a dangerous blood clot in their deep veins or lungs, according to research from the University of Michigan Health System.
Those who got the infection at home were nearly three times more likely to be sent to the hospital for a blood clot within 90 days.
The most common predictor of hospitalization for venous thromboembolism—a potentially life-threatening condition that includes both deep-vein and lung blood clots—was recent exposure to an infection, according to the study in Circulation.
"Over half of older Americans who were hospitalized for such blood clots had an infection in the 90 days prior to the hospitalization," said Mary Rogers, PhD, MS, research assistant professor in Internal Medicine at the University of Michigan Medical School.
The study comes as the rate of hospitalization for venous thromboembolism steadily increases in the United States, with more than 330,000 hospital admissions for this condition a year, researchers said.
"We would like to decrease the number of preventable hospitalizations, both for the benefit of the patient and to help bring down the cost of medicine," Rogers said.
The study also found that other strong predictors of hospitalization for blood clots included blood transfusions and drugs prescribed to stimulate red blood cell production (known as erythropoiesis-stimulating agents), which are sometimes given to treat anemia. The risk of hospitalization for blood clots was nine times greater after the use of these drugs.
Rogers and her colleagues conducted the study using participants in the Health and Retirement Study, a nationally representative sample of older Americans, and combined their information with Medicare files. The Health and Retirement Study is conducted by the U-M Institute for Social Research on behalf of the National Institute of Aging.
"Often we don't think about the downstream consequences of infection," Rogers said. "The infection itself may trigger blood clots in your deep veins, which may travel to your lungs and block the arteries there.
“This can be fatal. It's a risk both patients and physicians need to be aware of."