SEATTLE – Gastric bypass did not extend the lives of older, severely obese patients in a Department of Veterans Affairs Study.
Though bariatric surgery is often assumed to extend lives, "physicians should advise patients such as those examined here that there is no survival benefit at nearly 7 years, and the longer-term survival benefit is still unknown," said lead author Matthew L. Maciejewski, Ph.D., of Duke University, Durham, N.C., and an investigator at the Center for Health Services Research in Primary Care at the Durham VA Medical Center at the annual research meeting of AcademyHealth.
He and his colleagues compared 850 VA Roux-en-Y gastric bypass patients with 41,244 nonsurgical controls. The operations were conducted between 2000 and 2006. The average age in the bypass group was 50 years and average body mass index was 47 kg/m2; 74% were men. The average age in the control group was 55 years and average BMI was 42 kg/m2; 92% were men.
At first glance, bypass patients appeared to do better after a mean follow-up of 6.7 years. Although 6.8% had died after 6 years, for instance, 15.2% had died in the control group (hazard ratio, 0.64; 95% confidence interval, 0.51-0.80).
The apparent advantage, however, diminished after covariate adjustment (HR 0.80; 95% CI 0.63-0.99), and vanished when patients were propensity matched one to one with the most similar controls based on age, sex, race, marital status, BMI, diagnosis related groups (DRG), and other factors (HR, 0.83; 95% CI, 0.61-1.14). When the investigators further adjusted for the start time, the advantage disappeared (HR, 0.94, 95% CI, 0.64-1.39).
In short, "the use of bariatric surgery, compared with usual care, was not associated with decreased mortality," Dr. Maciejewski and his colleagues concluded (JAMA 2011 June 12 [doi:10.1001/jama.2011.817]).
The results mean "you should not select people [for surgery] thinking they are going to live longer. If someone comes to you and says, ‘I want bariatric surgery because it’s going to improve my longevity,’ the answer is ‘no.’ There’s no study that definitively shows that might even be the case," said coauthor Dr. Edward Livingston, chairman of the GI and endocrine surgery division at the University of Texas Southwestern Medical School at Dallas.
Selection instead should be based on immediate concerns. Out-of-control diabetes, a patient too big to get around, sleep apnea, failing joints, and other weight-related problems make "surgery a reasonable option," said Dr. Livingston, who’s been performing bariatric surgeries since 1993.
The findings contradict previous studies suggesting a survival benefit for bariatric surgery, but those studies were largely of younger women with inherently lower obesity-related mortality risks, or foreign studies that don’t translate well to the United States, he said.
In contrast, the veterans in the study – older, obese, and comorbid – "die at a very high rate, so we expected [surgery to demonstrate] a big benefit in a short amount of time. The belief is if you take people that are really sick with diabetes, hypertension, and sleep apnea, and get a lot of weight off them, they live longer. We didn’t see it. This is the first study to show that doesn’t actually happen," he said.
The researchers have previously shown that bariatric surgery did not cut the health care costs of their cohort within 3 years (Med. Care 2010;48:989-98).
Dr. Maciejewski is paid consultant to Takeda Pharmaceuticals and Novartis and owns stock in Amgen. Dr. Livingston is a paid consultant to Texas Instruments. The study was funded by the Department of Veterans Affairs.