Richer Data Strengthen Evidence of Lower Mortality Rates After Bariatric Surgery

By Hannah Stuart
Thursday, November 1, 2018

The most common bariatric surgeries markedly increase obese patients’ chances of living longer, according to a recent study published in JAMA that builds on evidence of the procedures’ benefits.

The study found that compared with conventional nonsurgical treatments, bariatric surgery reduces the death rate for this patient group by 50 percent.

“We showed that a long-term effect of bariatric surgery is a longer life for obese patients,” Philip Greenland, MD, study co-author and Professor of Preventive Medicine at Northwestern University Feinberg School of Medicine, stated in a news release. “They had half the death rate, which is significant.”

Researchers from Northwestern partnered with Clalit Research Institute, the largest HMO in Israel. They compared all-cause death rates among approximately 8,400 patients in Israel who had undergone one of the three most common types of bariatric surgery — Roux-en-Y gastric bypass, laparoscopic banding and sleeve gastrectomy — with those of 25,200 people who had received nonsurgical obesity management. The median age of participants was 46.

There were 105 deaths among surgical patients and 583 among nonsurgical patients over a median follow-up of about 4.5 years. Among patients who died, median time to mortality was 3.7 years.

While past studies typically examined only Roux-en-Y gastric bypass, data available through Clalit enabled researchers to factor in results from laparoscopic banding and sleeve gastrectomy as well. There were no dramatic differences in death rates for each procedure, according to Laura J. Rasmussen-Torvik, PhD, MPH, co-author of the study and Assistant Professor at Feinberg School of Medicine.

A More Complete Picture

While the 50 percent decrease in death rate reinforces findings from other recent research, the data available from Clalit give a fuller picture than past studies have provided.

For example, 65 percent of participants were women. Previous studies, including one that examined veterans who underwent Roux-en-Y gastric bypass, had patient samples that were largely men. Women represent the majority of people who undergo bariatric surgery in Israel and the United States; therefore, the Clalit data more accurately reflect the patient population.

In addition to patient demographics, participant retention sets this study apart. The study population had an annual dropout rate of less than 2 percent.

“Because they have fairly good health coverage in Israel, people are going to the doctor with more regularity than they will have in the United States,” Rasmussen-Torvik says. “We have really good quality of follow-up data.”

Evidence-Based Decisions

“One thing the public and the patient population should feel reassured by is the fact that bariatric surgery has matured,” says Eric DeMaria, MD, President-elect of the American Society for Metabolic and Bariatric Surgery and bariatric surgeon at Bon Secours St. Mary’s Hospital in Richmond, Virginia. “It’s no longer, ‘Pick this one operation or don’t have the surgery.’ ... There’s a lot of room here for patients to exercise their ability to make choices as far as how they are treated.”

In future research, Rasmussen-Torvik wants to break down the data even further to provide information tailored to various patient demographics. She believes that will empower patients and physicians alike to make better choices with regard both to whether to undergo bariatric surgery and, if so, which one to select.

“Because of the size ... and richness of this data set, we’re really interested in examining mortality and other outcomes in specific strata — in men, in women, in people of different ages [and] in people with different baseline BMIs,” Rasmussen-Torvik says. “Information we can provide that gives people a picture of how they might do with bariatric surgery, or what advantages they might have, I think really helps tailor the decision-making process.”