When patients get infections in the hospital, the ramifications can be expensive—and sometimes deadly.

Hospital-acquired infections (HAIs), including staph, pneumonia, sepsis and others, account for 44,000 to 98,000 deaths and $17 billion to $29 billion in additional costs each year, the Institute of Medicine (the health arm of the National Academy of Sciences) estimated about a decade ago.

"Infections that are acquired during the course of a hospital stay cost the United States a staggering amount in terms of lives lost and health care," Ramanan Laxminarayan, director of the Center for Disease Dynamics, Economics and Policy at the nonprofit research group Resources for the Future, said in a prepared statement.

He and a group of fellow researchers wanted to create a more detailed picture of how these infections are affecting patients and health care costs. "Previous estimates of the health consequences and economic costs attributable to HAIs remain contentious," Laxminarayan and his colleagues noted in a study published online February 22 in the Archives of Internal Medicine. Faulting small sample sizes and lack of statistical controls of other reports on the issue, the team used the Nationwide Inpatient Sample database to search 69 million hospital discharges between 1998 and 2006 in 40 different states. They focused on pneumonia and sepsis infections—both frequent results of improper care in hospital settings—to reduce overlap with community-acquired infections and pre-existing conditions; they also controlled for patient diagnosis, demographics, co-morbidities, hospital treatment and possible exposure before admission.

From this analysis, the team estimated that these two HAIs alone caused some 48,000 deaths, an additional $8.1 billion in care costs and about 2.3 million extra days in the hospital in 2006 (the last year for which data was available). And these figures are likely to be conservative, the researchers argued, because the data "focus on infections that were acquired and diagnosed during the same hospitalization, although many HAIs…are not diagnosed until hospital discharge."

How can these numbers be reduced? "In many cases, these conditions could have been avoided with better infection control in hospitals," Laxminarayan said. But as superbug infections such as MRSA (methicillin-resistant Staphylococcus aureus) spread, they "are increasingly difficult to treat," Anup Malani, a law professor at the University of Chicago and co-author of the study, said in a prepared statement.

Not all of the infections occurred in patients who were already sick in the hospital. Infections from elective surgery can result in infection as well and can often end up incurring even greater costs than cases in which a person was already hospitalized, the researchers found. "In some cases, relatively healthy people check into the hospital for routine surgery," Malani said. "They develop sepsis because of a lapse in infection control—and they can die."

Commenting on the study in a published response in Archives, David Murphy and Peter Pronovost, both of Johns Hopkins University in Baltimore, asserted that the persistence of widespread harm from HAIs is "unconscionable" but given "our shortcomings in providing care are entirely understandable and predictable." They note that these rates are likely to remain high until more research goes into "the science of health care quality and safety."

The study authors concluded that time is of the essence, though. "Hospitals and other health care providers must act now to protect patients from this growing menace," Laxminarayan said. And as a financial bonus, Malani added, "improving infection control is a clear way to both improve patient outcomes and lower health care costs."

Image courtesy of iStockphoto/SilviaJansen