For older patients, the risk of death associated with elective surgery is far greater than previously estimated, and frequently higher than 10%, according to a new Dartmouth study.

Reviewing major elective procedures in more than a million patients ages 65 to 99, Dartmouth researchers found that mortality risk increases with age. Deaths associated with surgery for patients 80 years and older was more than twice that for patients 65 to 69 years old. Their findings were reported in the July/August 2001 medical journal, Effective Clinical Practice.

John Birkmeyer, M.D., associate professor of surgery at Dartmouth Medical School, and Emily Finlayson, M.D., research fellow at White River Junction VA Medical Center, found that operative mortality for major surgery varies by procedure and patient age.

Most shocking, however, was their finding that the death rate is considerably higher than that typically reported in case series and trials of operative mortality.

Operative mortality is defined as death within 30 days of the operation or death before discharge.

"When reviewing surgical risks with patients, surgeons often rely on one-size-fits all-estimates, which tend to be unrealistically low," said Dr. Birkmeyer. He added, "Both surgeons and patients need to be aware that operative mortality depends strongly on patient factors -- particularly age. Elderly patients often have risks two- to four-fold higher than younger patients. Mortality risks also depend on where the surgery is performed. Unfortunately, some hospitals have much higher mortality rates than others."

Taken together, all of these factors can give patients a more realistic starting point for understanding surgical risk. For those considering elective major surgery, information about operative mortality risks is essential for careful decision making.

However, that information is often limited to educated guesses or optimistic data from case series, the researchers noted.

The study showed, for example, that carotid endarterectomy to unblock the carotid artery had the lowest overall operative mortality (1.3%) while the highest overall mortality (8.6% to 13.7%) was observed for removal of all or part of the stomach (gastrectomy), esophagus (esophagectomy) and lung (pneumonectomy), and major pancreatic resection.

Patients and physicians should have ready access to operative mortality data based on observed mortality in actual practice, said Drs. Finlayson and Birkmeyer, and should have the best possible information from their physician when making a decision about elective surgery.

The Dartmouth researchers examined mortality in 1.2 million patients in the Medicare system who were hospitalized between 1994 and 1999 for 14 high risk elective surgeries (six cardiovascular procedures and eight major cancer resections).

SOURCES: "Dartmouth/VA study reveals new, realistic estimates for surgery survival in older Americans," Dartmouth Medical School, Aug. 20, 2001.

Effective Clinical Practice, Jul/Aug 2001.