Recent data suggests a decline in the number of Australians undergoing bariatric surgery, even as those who do choose the procedure continue to experience significant benefits, including substantial weight loss and improved management of diabetes.
The 2023 Annual Report from the Australia and New Zealand Bariatric Surgery Registry (ANZBSR), led by Monash University, highlights that patients who underwent bariatric surgery in 2023 lost an average of 29% of their total body weight within the first year. Furthermore, more than half of the patients with diabetes were able to discontinue treatment a year post-surgery.
The report, which details procedures in both Australia and Aotearoa New Zealand for the year 2023, includes complication data from July 2022 to June 2023. In 2023, the registry documented 19,599 bariatric procedures in Australia, including 15,985 primary procedures and 3,614 revision surgeries. This figure is part of a broader trend, with the Medicare Benefits Schedule (MBS) recording 21,044 procedures for the year—the lowest number since 2016.
A significant finding from the report is that the vast majority of these procedures were privately funded, with 95% of primary and 93% of revision surgeries falling into this category. Women constituted 79.1% of all participants, with the most common age group for women being 30–34 years, while for men, it was 40–44 years. The average age for primary procedures was 42 years, and among these patients, 9% of women and 15% of men had diabetes before surgery.
Complication rates for primary procedures remained low, with the most common surgery, primary sleeve gastrectomy, showing an adverse event rate of under 2%. The rate was slightly higher, though still below 5%, for primary gastric bypass surgeries. However, the report notes that if complications occurred, the likelihood of further complications increased.
Long-term outcomes for Australian patients post-surgery were notably positive:
- An average total weight loss of 29% one year after a primary bariatric procedure.
- A 73% average excess weight loss within the same period.
- 56% of those with diabetes at the time of surgery required no medication for the condition one year later.
- 70% of participants who were on insulin before surgery no longer needed it after 12 months.
- Only 4.1% of patients required additional bariatric procedures or interventions within a year of their initial surgery.
Despite these positive outcomes, the report, led by Professor Wendy Brown, Clinical Director of the Bariatric Surgery Registry at Monash University, suggests the decline in surgery numbers may be attributed to the increasing availability and effectiveness of non-surgical pharmaceutical treatments that offer similar weight loss benefits.
“Both patients and practitioners may be opting for these safer, non-invasive options, particularly given the current economic climate where the cost of surgery can be prohibitive, and the fear of job insecurity may make extended recovery times less feasible,” said Professor Brown. She also noted that the drop in numbers was more significant in revision procedures, indicating a possible preference for pharmaceutical options when surgical interventions no longer deliver the desired results.
The ANZBSR has been operational since its pilot launch in Melbourne in 2012, expanding significantly with federal government support in 2014, and including New Zealand from 2018 onwards. To date, the registry has documented over 180,000 procedures involving more than 170,000 participants.
In 2023 alone, the registry captured 17,203 procedures in Australia, maintaining an 81.7% capture rate, consistent with the 80% rate it has sustained since 2020. The majority of the 15,985 primary procedures performed in 2023 were sleeve gastrectomies (79.8%), followed by one anastomosis gastric bypass (10.9%) and Roux-en-Y gastric bypass (8.6%).
The registry operates on an opt-out basis for adult participants, with written parental consent required for minors under 18 in Australia and under 16 in New Zealand. Since its inception, it has recorded 179,336 procedures in Australia and 8,726 in New Zealand, covering 162,991 participants in Australia and 8,541 in New Zealand.
Despite the complexity of these procedures, mortality rates remain low, with the registry documenting just 62 deaths within 90 days of surgery out of 179,690 procedures recorded since 2012.
