Medicare patients have a substantially higher risk of early death following bariatric surgery than previously suggested

Oct 19 2005

Medicare patients have a substantially higher risk of early death following bariatric surgery than previously suggested, and the risk of death is higher among men, older patients, and patients of surgeons who perform lower numbers of bariatric procedures, according to a study in the October 19 issue of JAMA: The Journal of the American Medical Association.

In the United States, most adults are overweight or obese, and obesity is soon to become the leading cause of death, according to background information in the article. Bariatric surgical procedures (surgery on the stomach and/or intestines designed to promote weight loss) are the only interventions that consistently help patients achieve significant and sustained weight loss and improvements with co-existing medical conditions. As a result, there has been dramatic growth in bariatric surgery over the last decade. Balanced against these beneficial effects, however, are the risks of perioperative death and short-term adverse outcomes, which have been poorly defined in the community at large.

David R. Flum, M.D., M.P.H., of the University of Washington, Seattle, and colleagues conducted a study to determine the risk of all-cause early postsurgical death among Medicare beneficiaries undergoing open bariatric surgery. The study examined early (30-day, 90-day, and 1-year) death figures for all U.S. fee-for-service Medicare beneficiaries who underwent bariatric procedures from 1997-2002.

A total of 16,155 patients underwent bariatric surgical procedures (average age, 48 years; 75.8 percent women, with 90.6 percent younger than 65 years). A total of 61.2 percent of cases were claims for the bariatric surgical procedure Roux-en-y gastroenterostomy (RYGB) and 19.9 percent were for RYGB with small intestine reconstruction to limit absorption. There was more than a 3-fold increase in the number of procedures performed from 1997 (n=1,464) to 2002 (n=4,814).

The researchers found that among all patients, the rates of 30-day, 90-day, and 1-year death were 2.0 percent, 2.8 percent, and 4.6 percent, respectively. Advancing age and male sex were associated with early death after bariatric surgery, with the highest rates of early death among older men. Overall, men were more likely to die after bariatric surgery than women (3.7 percent vs. 1.5 percent, 4.8 percent vs. 2.1 percent, and 7.5 percent vs. 3.7 percent for men and women at 30 days, 90 days, and 1 year, respectively). Death rates were greater for those aged 65 years or older (n=1,517) compared with younger patients (4.8 percent vs. 1.7 percent, 6.9 percent vs. 2.3 percent, and 11.1 percent vs. 3.9 percent at 30 days, 90 days, and 1 year, respectively).

After adjustment for sex and co-existing illness index, the odds of death within 90 days were 5-fold greater for older Medicare beneficiaries (aged 75 years or older; n=136) than for those aged 65 to 74 years (n=1,381). The odds of death at 90 days were 1.6 times higher for patients of surgeons with less than the median surgical volume of bariatric procedures (among Medicare beneficiaries during the study period) after adjusting for age, sex, and co-existing illness index.

"There may be several reasons for these findings. Older patients do not tolerate surgical stress as well as younger patients and may also have less benefit after surgery than younger patients because much of the impact of obesity on organ systems, such as the heart, may have occurred by the time of the operation. It also remains to be seen if surgical weight loss in older patients decreases utilization of health care resources, improves functional status and quality of life, or extends survival as has been suggested in studies of younger patients," the authors write.

"In conclusion, this study found that the risk of early postsurgical death among Medicare beneficiaries undergoing bariatric surgery was considerably higher than prior case series have suggested and was strongly associated with advancing age, male sex, and lower surgeon volume. Those considering the role of bariatric procedures in older patients should balance this population-level risk of adverse outcomes against the anticipated benefits of the procedure. Directing care of older patients to surgeons who perform higher volume of bariatric procedures in Medicare beneficiaries might be expected to improve outcomes in this high-risk population," the researchers write.