Surgical Infection Rates Lower in Elderly

Mystery remains as to why rates decline after age 65

FRIDAY, April 1, 2005 (HealthDay News) -- Risks for infection at the site of surgery appear to rise each year until age 65, when the risk steadily begins to decline, a new study reports.

The finding, which the researchers consider surprising, could have implications for decisions regarding surgery in elderly patients, according to the study's lead author, Dr. Keith Kaye, an assistant professor of infectious diseases at Duke University Medical Center.

"If elders are at a decreased risk due to a surgical selection bias -- in which only healthier elders are selected for surgery -- this is important to know and address," Kaye said in a prepared statement. "Maybe age shouldn't be weighted heavily in surgical selection issues."

As reported in the April 1 issue of the Journal of Infectious Diseases, the study of more than 144,000 surgery patients found no surgical site infections in patients older than 95.

His team found that the risks for surgical infections increased by 1.1 percent a year between the ages of 17 and 65, but then decreased by 1.2 percent a year in patients 65 and older.

"I was surprised by the results," Kaye said. "Generally, risk for infection increases with age, and I expected surgical site infection risk to also increase with age."

Kaye said the findings also raise important questions about the immune systems of older patients.

"If the decreased risk is associated with an innate immune phenomenon, it would be important to understand this process and its implications for other types of infections," he said.

According to Kaye, surgical site infections occur in more than 325,000 patients each year in the United States and cost more than $1 billion in care.

More information

The U.S. Centers for Disease Control and Prevention has more about surgical site infections.

SOURCE: Duke University, news release, March 30, 2005
Consumer News