A new study presented recently at the 2013 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS) identifies characteristics that put hip-fracture patients at risk for in-hospital death.

Approximately 340,000 Americans end up in the hospital each year because of hip fractures, and a small percentage die after developing a complication such as a blood clot that travels to the lung (called a pulmonary embolism), pneumonia or an infection.

Researchers from the William Beaumont Army Medical Center, in El Paso, Texas, analyzed data from the 2008 National Sample Program of the National Trauma Data Bank (NSP/NTDB). The NSP/NTDB, created by the American College of Surgeons, gathers data from 100 selected trauma centers around the country to create a nationally representative registry.

The researchers identified a representative sample of 44,419 hip-fracture cases. The average patient age was almost 73 years and 62 percent were female; 88 percent of patients were white, 6 percent were African-American and 6 percent were Hispanic.

The researchers found that, overall, about 4.5 percent of hip-fracture patients die in the hospital. But the risk of death climbs significantly when one or more complications set in. About 12.5 percent of patients will develop a complication – and of those, 17 percent will die.

Among the factors that increase the risk of mortality are: being male, having cardiac disease, presenting in shock and being a dialysis patient. Being a male, for example, more than doubles the risk of death, presenting in shock almost triples it and being a dialysis patient increases it more than six-fold.

Among the factors that increase the risk of a complication are: being a dialysis patient, presenting in shock, being obese, having cardiac disease and having diabetes.