Report shows fewer Australians are having bariatric surgery

Fewer Australians are having bariatric surgery, and a new report shows the results for those who do are mostly positive, including significant weight loss and big improvements for those with diabetes.

The Australia and New Zealand Bariatric Surgery Registry's 2023 Annual Report found participants lost an average 29% of their total body weight in the first year post-surgery, and more than half of those who had diabetes required no treatment a year after surgery.

The report covers procedures in Australia and Aotearoa New Zealand for calendar year 2023, and complications data from July 2022 to June 2023.

In calendar year 2023, the registry, led by Monash University with partner organizations, captured 19,599 Australian procedures. This included 15,985 primary and 3,614 revision procedures.

The total number recorded by the Medibank Benefits Schedule (MBS) was 21,044, the lowest since 18,980 in 2016. The registry captures around 80% of these.

Registry figures found most 2023 Australian bariatric surgery procedures were privately funded (95% primary and 93% revision) and 79.1% of participants were female.

The 30–34 age group was most common for women; for men, it was 40–44. The average age for having a primary procedure was 42. Nine percent of women and 15% of men had diabetes before surgery.

Primary procedures had relatively few complications. The most common procedure, primary sleeve gastrectomy, had an adverse event rate lower than 2%. The rate was less than 5% for the primary gastric bypass procedures. If a complication occurred, the rate of additional complications increased.

Long-term outcome data for Australia showed:

• 29% average total weight loss at one-year following a primary bariatric procedure
• 73% average excess weight loss at one-year following a primary bariatric procedure
• 56% of people with diabetes at time of primary procedure were reported as requiring no medication for diabetes at one-year follow-up
• 70% of participants on insulin for diabetes at the time of surgery no longer required insulin after 12 months
• 4.1% of people who had a bariatric procedure went on to have at least one more bariatric procedure or subsequent intervention

In the report, Monash University Professor Wendy Brown, Clinical Director Bariatric Surgery Registry, said the drop in surgery numbers could be partly due to the significant uptake of very effective pharmaceuticals that provided weight loss similar to bariatric surgery at one year.

"It may be that practitioners and patients are opting for non-surgical pharmaceutical options rather than surgery," Professor Brown said. "We are also facing significant cost of living challenges, meaning that the cost of surgery now might be prohibitive for some, or people may fear being away from work when their job is under threat."

Professor Brown said while it was clear there had been a decline in primary and revision procedures, the drop was more pronounced in the revisional setting.

"This possibly suggests that patients and practitioners are choosing the safer pharmaceutical option for weight loss rather than more aggressive surgery when metabolic bariatric procedures are no longer providing the required weight loss," Professor Brown said. "This is a pattern we will continue to monitor in years to come."

The registry began as a pilot project in Melbourne in 2012, and expanded significantly with federal government funding in 2014. Aotearoa New Zealand joined the program in 2018. In total, the registry has recorded more than 180,000 procedures for more than 170,000 participants.

In 2023, the Medicare Benefits Schedule (MBS) recorded 21,044 bariatric procedures in Australia. The registry captured 17,203 (81.7%) and has captured more than 80% since 2020.

Most of the 15,985 primary bariatric procedures recorded in 2023 were sleeve gastrectomy (79.8%), followed by one anastomosis gastric bypass (10.9%), Roux-en-Y gastric bypass (8.6%) and other types of primary procedures (0.7%) including laparoscopic gastric band, single anastomosis duodeno-ileostomy (SADI)/stomach intestinal pylorus-sparing surgery (SIPS) and other.

In total, the registry, which uses an opt-out approach for recruitment of adults and written parental consent for those under 18 (in Australia) or 16 (in New Zealand), has captured 179,336 procedures from Australia and 8,726 from Aotearoa New Zealand for 162,991 participants in Australia and 8,541 in New Zealand. An additional 354 procedures were not reported further.

Deaths are rare. Overall, the registry has recorded 62 deaths within 90-days of a primary or revision procedure for 179,690 Australian procedures (including abandoned procedures) since 2012.