2017/18 report - monash university · excess weight loss (ewl) measure of the percentage of excess...

BARIATRIC SURGERY REGISTRY2017/18 REPORT

FUNDING PARTNERS

The Bariatric Surgery Registry received funding in the last 12 months from the Commonwealth Government of Australia and the following supporters:

The Registry would like to acknowledge and thank Medtronic for providing the start-up funding required for the New Zealand arm of the Registry.

CONTENTS

LIST OF FIGURES 1

LIST OF TABLES 2

FUNDING PARTNERS 2

FOREWORD FROM CHAIR OF STEERING COMMITTEE 3

LIST OF ABBREVIATIONS 4

DATA PERIOD 4

COMMON TERMS AND DEFINITIONS 5

EXECUTIVE SUMMARY 6

SNAPSHOT OF THE BARIATRIC SURGERY REGISTRY 7

BACKGROUND 8

Rationale for a Registry and Collaborators 8Governance 9

REGISTRY METHODOLOGY 10

Data Elements 10Data Collection Processes 10Patient Reported Outcome Measures 10Data Reporting 11Site and Surgeon Accrual 11

RESULTS FOR THE REGISTRY AS AT 30 JUNE 2018 13

Enrolment in the Registry 13Procedures Captured by the Registry 15Demographics 23Follow Up 26Safety Reporting 27Weight Outcomes 31Diabetes Outcomes 34

CONCLUSION 36

ACKNOWLEDGEMENTS 37

COMMITTEES AND STAFF 38

APPENDIX 1: DATA ELEMENTS CAPTURED 39

APPENDIX 2: LIST OF PARTICIPATING SITES 40

Australia 40New Zealand 40

LIST OF FIGURES

Figure 1 Surgeons and Hospital Sites Actively Contributing to the Registry per Financial Year 14

Figure 2 Number of Hospital Sites and Number of Surgeons per State Contributing to the Registry for FY 17/18 15

Figure 3 Accumulation Rate of Participants in the Registry by Patient Type from February 2012 to 30 June 2018 16

Figure 4 Change in Procedure Type Captured by Registry 18

Figure 5 Procedures Captured by the Registry by State and Procedure Type (FY 17/18) 19

Figure 6 Primary Procedures Captured by the Registry by State and Public/Private (FY 17/18) 19

Figure 7 Revision Procedures Captured by the Registry by State and Public/Private (FY 17/18) 20

Figure 8 MBS Capture Rates from FY 13/14 to FY 17/18 21

Figure 9 Primary and Revision Procedures Captured by the Registry in Private vs Public Hospitals in Australia (FY 17/18) 22

Figure 10 Revision Incidence Rates for Primary Bariatric Procedures as at 30 June 2018 24

Figure 11 Participants’ Age Distribution at Time of Primary Procedure (FY 17/18) 27

Figure 12 Participants’ Age Distribution at Time of Revision Procedure (FY 17/18) 27

Figure 13 Participants’ Weight at Time of Procedure (FY 17/18) 28

Figure 14 Reasons Attributed for Defined Adverse Events in all Participants (FY 17/18) 31

Figure 15 Reasons Attributed for Reoperation on Primary Participants (FY 17/18) 31

Figure 16 Start BMI and Day of Surgery BMI Classification for Primary Participants from February 2012 to 30 June 2018 (n=22,825) 32

Figure 17 Excess Weight Loss and Total Weight Loss for Primary Participants who have reached 3 Year Annual Follow Up (n=1,638) 33

Figure 18 Excess Weight Loss and Total Weight Loss for Primary Participants who have reached 4 Year Annual Follow Up (n=613) 34

Figure 19 Primary Participants Identifying as having Diabetes and Treatment at Primary Procedure from February 2012 to 30 June 2018 (n=37,765 primary participants) 35

Bariatric Surgery Registry Sixth Annual Report: 2017/18 1

LIST OF TABLES

Table 1 Patient Participation in the Registry from 1 July 2014 to 30 June 2018 16

Table 2 Procedures Performed by Type 17

Table 3 Procedures Captured by the Registry by State (FY 17/18) 20

Table 4 Procedures Performed in Public Hospitals in Australia 20

Table 5 Concurrent Renal Transplants 21

Table 6 Primary Procedures in the Registry by Type 21

Table 7 Number of Procedures Undergone by Participants from February 2012 to 30 June 2018 22

Table 8a Current Status of Sleeve Gastrectomy Primary Participants as at 30 June 2018 23

Table 8b Current Status of Gastric Banding Primary Participants as at 30 June 2018 23

Table 8c Current Status of RY Gastric Bypass Primary Participants as at 30 June 2018 24

Table 8d Current Status of One Anastomosis Gastric Bypass Primary Participants as at 30 June 2018 24

Table 9 Number of Procedures Undergone by Legacy Participants from February 2012 to 30 June 2018 24

Table 10 Demographics of Participants at Their Procedure (FY 17/18) 25

Table 11 Follow Up Completion by Type 27

Table 12 Deaths Reported to the Registry up to 30 June 2018 28

Table 13 Cause of Death when Death was Likely Related to Bariatric Procedure as at 30 June 2018 28

Table 14 Defined Adverse Events in all Participants up to 30 June 2018 29

Table 15 Primary Procedures by Type with a Defined Adverse Event (FY 17/18) 29

Table 16 Revision Procedures by Type with a Defined Adverse Event (FY 17/18) 29

Table 17 Mean BMI for All Primary Procedures from February 2012 to 20 June 2018 31

Table 18 Weight Outcomes at 12 Months for All Primary Procedures from February 2012 to 30 June 2018 32

Table 19 Primary Participants Identifying as having Diabetes at Baseline from February 2012 to 30 June 2018 33

Table 20 Treatment for Diabetes at Baseline from February 2012 to 30 June 2018 33

Table 21 Treatment of Participants with Diabetes Reported at Baseline Followed Up at 12 Months 34

2 Bariatric Surgery Registry Sixth Annual Report: 2017/18

FOREWORD FROM CHAIR OF STEERING COMMITTEE PROFESSOR IAN CATERSON

This is the sixth report of the Bariatric Surgery Register (BSR). It continues to get bigger and bigger (as I said last year) and we now have 47,649 participants in the register and over the 12 months have added 19,341 participants. We have had a total of 147 surgeons and 98 hospitals contribute to the Registry over the past financial year.

Another major happening this year is that we have started to collect data from New Zealand and over the next 12 months, we need to strengthen this activity and ensure the continuing contribution to the Registry.

This has meant a great deal of work to ensure that the data is collected, that there is ethics clearance and consent in all cases and that those who have had bariatric surgery are followed up regularly. This work is carried out daily by the staff in the Registry, by surgeons, by the staff in their rooms and in theatres and we are really grateful for their hard work, expertise and continuing interest. The Registry can only be as good as the data it gets.

The difficulty of getting the longer-term follow up continues. We are committed to getting greater than 95% continuing follow up! Please, please help us to get this data.

There is interest in our registry, its data and potential from overseas, from governments and because we have made as sure as we can that the data is collected properly, that we do have involved surgeons and staff, we are seen as trustworthy and or data output useful.

Now is the time we can start producing outputs on the effectiveness of bariatric surgery in our countries. We are happy to receive research proposals for use of de-identified data and we have established a process for dealing with these requests. If you have a burning question you want to examine about bariatric surgery and its outcomes, please send us a proposal.

Once again, we must thank the staff of the BSR – they continue to deal with problem issues calmly and efficiently, they are really involved and so helpful.

Thank you all.

Professor Ian D Caterson Director, Boden Institute, Charles Perkins Centre, University of SydneyDirector, Charles Perkins Centre Royal Prince Alfred ClinicPast-President, World Obesity Federation

We are committed to getting greater than 95% continuing follow up!


LIST OF ABBREVIATIONS

ANZGOSA Australia and New Zealand Gastro-Oesophageal Surgery Association

ANZMOSS Australian and New Zealand Metabolic and Obesity Surgery Society (formally OSSANZ)

ACSQHC Australian Commission on Safety and Quality in Health Care

AMA Australian Medical Association

BMI Body Mass Index

BPD/DS Bilio-Pancreatic Device with Duodenal Switch

BSR Bariatric Surgery Registry

DOS Day Of Surgery

FY Financial Year

ICD-10-AM Australian modification of the International Statistical Classification of Diseases and Health Related Problems, 10th revision

ICU Intensive Care Unit

IT Information Technology

LAGB Laparoscopic Adjustable Gastric Banding

LSG Laparoscopic Sleeve Gastrectomy

LTFU Lost To Follow Up

MBS Medical Benefits Schedule

NSW New South Wales

NZ New Zealand

OAGB One Anastomosis Gastric Bypass (previously called Single Anastomosis Gastric Bypass)

OP Operation

PROMs Patient Reported Outcome Measures

QLD Queensland

RACS Royal Australasian College of Surgeons

RYGB Roux-Y Gastric Bypass

SA South Australia

SPHPM School of Public Health and Preventive Medicine, Monash University

ST DEV Standard Deviation

TAS Tasmania

VIC Victoria

WA Western Australia

DATA PERIODThe data contained in this document was extracted from the Bariatric Surgery Registry as at 27th July 2018 but pertains to procedures that have occurred up to 30 June 2018. As the Registry does not capture data in real time, there may be a lag period between the occurrence of an event and its capture in the Registry’s database, BSR-i.


COMMON TERMS AND DEFINITIONS

Primary Participant Patient whose first entry into the Registry is with their initial bariatric surgical procedure

Legacy Participant Patient whose first entry into the Registry is with a subsequent (or revision) bariatric surgical procedure

Primary Procedure The initial bariatric procedure performed upon a patient

Revision Procedure A subsequent bariatric procedure performed upon a patient who has had a primary procedure

Opt-Out Patients who have been sent Explanatory Statements and who have elected to not have their data included in the Registry

Partial Opt-Out Patients who have been sent Explanatory Statements and will allow the Registry to keep their information but do not want to be contacted by the Registry

Contributing Site Any hospital site currently contributing data to the Registry

Contributing Surgeon Any surgeon currently contributing data to the Registry

Class I Obesity Defined as a body mass index (BMI, kg/m2) of 30 or over

Class II Obesity Defined as having a body mass index (BMI, kg/m2) of 35 or over

Class III Obesity Defined as having a body mass index (BMI, kg/m2) of 40 or over

Initial Weight Taken as the higher of the weight at Intention to Treat or weight at Operation of a Primary Participant

Excess Weight Loss (EWL) Measure of the percentage of excess weight a patient has lost from one time point to another where excess weight is defined as the patient’s initial weight minus their ideal weight at BMI 25

Total Weight Loss % (TWL) Measure of the percentage of weight a patient has lost from one time point to another. In the Registry this is measured from the patient’s initial weight

Peri-operative Follow Up Participant observation from any visit between 20-90 days post-operative (previously called 30 day follow up)

Annual Follow Up Participant observation taken from any visit on an annual basis from the Primary operation

Defined Adverse Event (Previously called sentinel event) indicated by the presence of a particular event occurring in the peri-operative phase (up to 90 days) in the healthcare setting, these are described as: 1. Unplanned Return to Theatre 2. Unplanned Admission to ICU 3. Unplanned Re-admission to Hospital

Financial Year Defined as the Australian financial year from 1 July to 30 June the following calendar year

Calendar Year Defined as the 12 month period from 1 January to 31 December in the same year


EXECUTIVE SUMMARY

The Bariatric Surgery Registry (BSR) is proud to present the Sixth Annual Report as at 30 June 2018. The Registry has had a successful year of operations where many milestones were achieved, namely:

• A total of 47,649 participants as at 30 June 2018 including the addition of 19,341 new participants in the past year;

• 3.5% increase in surgeons contributing bringing the total who have contributed in FY 17/18 to 147;

• 3.1% increase in hospitals contributing bringing the total who have contributed in FY 17/18 to 98;

• 64.9% MBS capture achieved, an increase of 16.7% from the previous FY 16/17; and

• The commencement of participation and data capture in New Zealand.

Similar to trends reported in previous years, the cohort of new participants attained during the FY 17/18 remains predominantly female (79%) and the mean age at the time of procedure was 44.1 years. Private hospitals were where 93.3% procedures occurred. For primary procedures, the mean BMI on day of surgery is 42.5 with 14.5% of participants identifying as having diabetes at this time.

The dominant procedure with 70.1% of all procedure captured in the FY 17/18 remains the Sleeve Gastrectomy. Sleeve Gastrectomies account for 84.3% of the total primary procedures captured in the FY 17/18 period.

The Registry has reported 46 deaths within the current participant cohort of which 6 cases are likely to be related to the procedure and another 24 awaiting determination of cause. The remaining 16 deaths have been attributed to something other than the procedure. During the FY 17/18 2.4% of primary procedures and 6.6% of revision procedures had a Defined Adverse Event (unplanned return to theatre, admission to ICU or re-admission to hospital) in the peri-operative period. In the primary participant cohort who have been tracked for up to six years, 992 participants required one or more revisions which represents 2.6% of the cohort.

A significant shift in diabetes status from baseline to 1-year post-operative was observed with 38% of participants no longer identifying as having diabetes. There was also a large reduction in treatment rates at 12 months after surgery to that recorded at baseline. This data will help guide studies in to Patient Reported Outcome Measures (PROMs) over the next 12 months.

One key strength of the Registry is its follow up data acquisition. This includes perioperative follow up of all procedures and 10-years of annual follow up for primary participants. The overall collection rate across all follow up time points is 74%. Weight, diabetes status and treatment as well as reoperation information is gathered at annual intervals to help strengthen the longitudinal data housed within the Registry. At 30 June 2018, there were 16,178 participants that have had a successful capture of year 1 annual follow up and 60 participants that have now reached the year 6 annual follow up mark.

With funding support from the Commonwealth Government, AVANT and Johnson&Johnson, the Registry will commence Patient Reported Outcome Measures (PROMs) research over the next 12 months, with the pilot phase focusing on quality of life currently being conducting in conjunction with the Cairnmillar Institute in Melbourne.

Looking into the next 12 months, the Registry will be improving data capture systems with the introduction of a new website and a secure platform portal to improve annual follow up capture, strengthening data linkages with State Governments and strengthening partnerships with surgeon’s electronic medical records to help minimise duplication of data entry. For Australia, the focus will be on recruiting the few remaining hospitals and surgeons to contribute to the Registry as well as the focus on a streamlined, multi-site ethics approval for over 100 hospitals through Alfred Health. The Registry will also be aiming to have all locality approvals completed for the New Zealand hospital sites and commence capturing valuable surgical outcome data to strengthen the bi-national cohort capture.

One key strength of the Registry is its follow up data acquisition. This includes perioperative follow up of all procedures and 10-years of annual follow up for primary participants.


SNAPSHOT OF THE BARIATRIC SURGERY REGISTRY

68%Increase in patient participation in the past 12 months to a total of 47,649 participants.

From 1 July 2017 to 30 June 2018, 19,341 participants joined the Registry.

68%Increase in operations captured in the past 12 months to a total of 51,277 primary and revision procedures.

From 1 July 2017 to 30 June 2018, 20,804 operations were added to the Registry.

3.5%Increase in surgeons contributing in the past 12 months to 147 surgeons contributing across Australia and New Zealand.

From 1 July 2017 to 30 June 2018, 5 new surgeons commenced contributing to the Registry.

3.1%Increase in hospitals contributing in the past 12 months to 98 hospitals contributing across Australia and New Zealand.

From 1 July 2017 to 30 June 2018, 3 new hospital sites commenced contributing to the Registry.

64.9% Of MBS procedure numbers captured across Australia for LAGB, RYGB, LSG and surgical reversals in the 2017/2018 period.


BACKGROUND

Rationale for a Registry and Collaborators

Obesity is one of the major challenges facing the Australian and New Zealand population. In 2009, the Australian Federal Parliament published the Georganas Report – Weighing it Up1 which detailed that the increasing obese and overweight population as a “pressing health concern for Australia”. In 2009, it was estimated that 24.6% of the adult population of Australia were obese.

In 2016, the AMA released a Position Statement on Obesity in 20162 estimating that the obesity rate in the adult population in Australia has increased to 27.9% or approximately 5 million adults. This escalation in obesity was referred to as “at a crisis level”2 and the call was made for the disease to be recognised as a priority where “a whole of society response to obesity should be strategic and coordinated”.

In New Zealand, the Ministry of Health’s Annual Update3 from the 2016/2017 Health Survey presented an increase in obesity in adults from 29% in 2011/2012 to 32% in 2016/2017 or approximately 1.2 million adults. Whilst it was noted that 34% of adults were classified as overweight but not obese.

Research has shown that obesity is a difficult disease to prevent and treat. Lifestyle interventions can be effective in the short term but maintenance of weight loss can be difficult to maintain over a longer period. Effective treatment options appear to be limited but for those that identify as being Class III obese (BMI >35) then bariatric surgery may be beneficial. Both Australia and New Zealand have observed a significant increase in the rate of bariatric surgery performed over the past decade and it was from this context that the Obesity Surgery Society of Australia and New Zealand (now ANZMOSS) supported the commencement of the Registry in 2012.

With the recommendation featured in the Georganas Report that a registry was required, the Registry was piloted in Victoria in 2012. The Commonwealth Government helped fund the Registry into the rollout phase with funding from May 2014 to July 2017 to ensure that Registry grew to nation-wide. Recently the Commonwealth have signed on to a five year funding agreement to support the Registry from July 2017 to September 2022. Industry funding from Gore, Medtronic and Applied Medical have greatly helped the Registry commence operations in New Zealand.

Following the promotion of driving change and improvements in patient care and outcomes heavily featured in the Australian Commission on Safety and Quality in Health Care (ACSQHC), The Registry seeks to answer the following:

a. Is this treatment safe? and

b. Is this treatment effective?

To ensure that these questions can be addressed, the Registry has been designed with the underlying principle to provide data that is accurate, complete and valuable. Accuracy and completeness is controlled by the definition, collection, verification, storage, and analysis and reporting as outlined in the data governance framework.

The Registry continues to encourage high-level stakeholder engagement and facilitates collaborations with governments, surgeons, private health groups, individual hospitals, medical technology and device industries, private health insurers and medical defence organisations to ensure that the data remains valuable. Most importantly, the Registry engages with participants to address how the Registry can aid in decision-making, assessment of risk and on-going journey of treatment. The involvement of the participants is paramount especially in regards to the data collection that Registry strives to achieve, especially the annual follow up data.

…the Registry has been designed with the underlying principle to provide data that is accurate, complete and valuable.


Governance

The Registry aligns with the fundamentals detailed in the ‘Operating Principles and Technical Standards for Australian Clinical Quality Registries 2008’ and the ‘Framework for Australian Clinical Registries 2014’ as published by ACSQHC. This is to ensure that, as a Registry, it aligns and complies with the national standard and provides assurance to all stakeholders.

The Registry is governed by the Steering Committee and this has convened since 2012, chaired by an independent, non-surgical obesity expert, Professor Ian Caterson. The Committee meets on a quarterly basis to advise the Registry on matters such as strategic direction, financial budget, data access, clinical quality and safety, quality development and operations. The BSR Programme Manager, in consultation with the Clinical Director for Australia, Professor Wendy Brown and the Clinical Lead for New Zealand, Associate Professor Andrew MacCormick, oversee the day-to-day operations of the Registry.

Current membership includes representatives from the following organisations and/or societies:

• Monash University

• Australian and New Zealand Metabolic and Obesity Surgery Society (ANZMOSS)

• Royal Australasian College of Surgeons (RACS)

• Australia and NZ Gastro-Oesophageal Surgical Association (ANZGOSA)

• Medical Technology Association of Australia (MTAA)

• Australian Commonwealth Department of Health

• Community Representation

One of the key achievements of the Steering Committee has been the establishment of the Data Governance Framework and the associated policies and processes that underpin the Registry including:

Protocol Data Dictionary (clinical & IT)

Outlier Policy BSR-i Business Rules

Privacy Policy Data Element Variation Processes

Grievance & Complaint Policy Data Capture Variation Processes

Call Centre Protocol & Scripts BSR-i System Change Request Processes

Data Access & Reporting Policy Reporting Templates

The Registry Custodian is the School of Public Health and Preventive Medicine (SPHPM) within the Faculty of Medicine, Nursing and Health Sciences at Monash University.

MONASH PUBLIC HEALTH AND PREVENTIVE MEDICINE


REGISTRY METHODOLOGY

Data Elements

The need for near complete data capture is required to ensure the reliability of the Registry. The collected data provides information on the patient (to allow tracking and to identify risk factors), the patient’s weight and BMI, the patient’s health (diabetes status and treatment), the type of surgery undertaken, whether a concurrent liver or renal transplant took place, the device utilised, the need for revision or repeat surgery, unplanned admissions to ICU or readmissions to hospital as well as mortality.

The current objective is for this minimal dataset to formulate the main “spine” of the Registry dataset however further data elements in relation to Patient Reported Outcome Measures (PROMs) will be added to the dataset in sub-studies of the Registry over the coming years. For the data elements that are collected, please refer to Appendix 1.

Data Collection Processes

Surgeons or hospital data collectors provide data about the bariatric patients and their procedures using one of the following options:

• Web browser with secure authorised entry using the Registry Interface (BSR-i)

• Paper based data forms (securely fax or posted)

• Secure electronic record transfer from surgeons’ or hospitals’ electronic medical record

Upon receipt of this information, the Registry sends the patient an Explanatory Statement about the Registry and their participation. The patient has a two-week period to opt-out of the Registry by calling a free-call 1800- number. Patients have the option to completely opt-out, meaning that no data is held in the Registry other than that needed to identify them should they have another procedure, or partial opt-out, meaning that they will allow their data to be held in the Registry but they do not wish to be called or contacted by the Registry. It is important to note that patients have the right to opt-out at any stage during the follow up period.

Hospital Information Services (HIS) at each hospital site provide regular ICD-10 coding reports for bariatric procedures performed by surgeons who participate in the Registry. The coding reports include patient demographic and procedure information. This data is sent to the Registry using a secure file transfer platform (SFTP).

ICD-10 coding reports provided by HIS are used to verify data submitted by surgeons/ hospital data collectors. If the surgeon and/or hospital has not previously provided information of a bariatric patient, the reports are used as the primary source of data. When ICD-10 coding is the primary source, surgeons are asked to complete the missing data elements not made available from the hospitals (e.g. device/stapling information, whether it was a primary or revision operation, height/ weight information and diabetes treatment).

Surgeons or public hospital clinics provide follow up data, either by return of a paper form or through submission on the BSR-i. If surgeons and/or public data collectors indicate they have not seen the participant, the BSR Call Centre staff will contact the participant for a brief 5-minute phone call to collect the follow up information related to the peri-operative period and/or 12-month intervals after surgery. Five attempts are made to contact the participant and if those attempts are not successful, the participant is a “Lost to Follow Up” (LTFU).

The Registry plans to develop an SMS and web-based secure portal platform to contact participants to obtain follow up information over the coming 12 months to help encourage the successful capture of follow up data from the participants.

Patient Reported Outcome Measures (PROMs)

In March 2017, the BSR engaged with the Cairnmillar Institute, Melbourne to commence the pilot phase study to examine a range of different psychosocial factors that affect the health and wellbeing of patients who have undergone bariatric surgery. The study, titled: Patients’ Expectations and Satisfaction following Bariatric Surgery – a study exploring the feasibility of including patient reported outcome measures in a national bariatric surgery registry commenced with focus groups in December 2017. Twelve (12) participants in total contributed discussions to the focus groups, held at the Cairnmillar Institute in Melbourne. Participants selected were located within a 20km radius of Melbourne and invited to participate via letter.

In March 2018, there were 1,500 BSR participants invited from around Australia to complete a questionnaire and another mail out of questionnaires is scheduled for August 2018 to increase the number of completed responses.

Following the analyses of results from Stage 1 of the project, Stage 2 will commence in the latter half of 2018 with the development of a large comprehensive item bank incorporating all potential items for the PROMS. This will be distributed to a large sample throughout Australia. From this, the development of a concise questionnaire to complement the longitudinal study of health and wellbeing outcomes for patients undergoing bariatric surgery will be finalised in 2019.

Over the next 12 months, the BSR will also commence PROMs initiatives to focus research on diabetes and health economics outcomes.


Data Reporting

The Registry follows a reporting cycle throughout the year to provide valuable data back to the key stakeholders. These reports include:

Released to: Report Type Reporting

Public Annual Report As at 30 June each year

Public Semi-annual Update As at 31 December each year

Surgeon Individual Surgeon Reports As at 30 September each year

Device Manufacturer (Funder) Individual Industry Reports As at 31 March each year

Hospital Group (Participant) Hospital Group Reports As at 31 March each year

The Registry also publishes a quarterly newsletter that is distributed to all internal and external stakeholders, hospitals and surgeons as well as potential new hospitals and surgeons that the Registry will seek to recruit. This newsletter is also published on the Registry’s website for participants to access.

Site and Surgeon Accrual

In 2013, members of the Australian and New Zealand Metabolic and Obesity Surgery Society (ANZMOSS) were encouraged to contribute to the pilot and initial phase of the BSR and from this, in June 2014, 185 surgeons across Australia and 15 surgeons in New Zealand that registered their interest for contributing to the Registry. This initial registration of interest helped created annual targets in which the Registry can strive to achieve.

Prior to commencing data collection at any given hospital site, the Registry required approval from the relevant ethics committee. After this approval has been obtained a Memorandum of Understanding (MoU) where a Local Principal Investigator is nominated, is signed between the Registry and the hospital site. Locality approvals and governance approvals are also obtained if required at each hospital site.

Figure 1 illustrates this exponential growth across Australia and New Zealand since the commencement of the Registry. Over the past 12 months, there has been a 3.1% increase in hospital site participation and a 3.5% increase in surgeon participation across Australia and New Zealand.

FIGURE 1 SURGEONS AND HOSPITAL SITES ACTIVELY CONTRIBUTING TO THE REGISTRY PER FINANCIAL YEAR


The Registry has observed an exponential uptake since the commencement of the Registry and as at 30 June 2018, the Registry had 147 surgeons from 98 hospitals across Australia and New Zealand contributing to the Registry.

FIGURE 2 NUMBER OF HOSPITAL SITES AND NUMBER OF SURGEONS PER STATE CONTRIBUTING TO THE REGISTRY FOR FY 17/18

* Please note there are 4 surgeons in Australia that contribute to the Registry in multiple states

7 HOSPITALS 17 SURGEONS

1 HOSPITAL 4 SURGEONS



1 HOSPITAL 1 SURGEON





RESULTS FOR THE REGISTRY AS AT 30 JUNE 2018

Enrolment in the Registry

As at 30 June 2018, there have been 50,399 Patient Explanatory Statements delivered inviting bariatric patients to participate in the Registry since February 2012. For a patient to receive an Explanatory Statement, they must have had their procedure on or before 30 June 2018. New Zealand statistics have been included in this total as recruitment of participants commenced in May 2018.

Of the 50,399 patients that have been invited to participate in the Registry, 1,898 (3.77%) have chosen to opt out and from the total number of patients invited, 271 (0.54%) elected to partially opt out, where their data will be kept but no further contact would be made. At the time of the data extraction, a further 852 (1.69%) patients that were pending participation status.

As at 30 June 2018, the Registry confirmed the participation of 47,649 bariatric patients and their data. It is from this cohort the report is derived.

Table 1 demonstrates the exponential growth of the Registry from 1 July 2014 to 30 June 2018. In the past financial year, there was a 68% increase in participant enrolment from the previous reported year and the Registry has maintained the opt out rate below 4%.

TABLE 1 PATIENT PARTICIPATION IN THE REGISTRY FROM 1 JULY 2014 TO 30 JUNE 2018

As at 30 June 2015 As at 30 June 2016 As at 30 June 2017 As at 30 June 2018^Participating 5,788 15,643 28,308 47,649*

Opt Out 213 554 1,146 1,898

Opt Out Rate 3.5% 3.4% 3.8% 3.77% * includes 74 participants who only had an abandoned procedure ^ includes Australia and New Zealand participants

Since commencing the Pilot Phase, some notable trends observed including exponential uptake of sleeve gastrectomy procedures from the national roll-out in July 2014. Figure 3 illustrates the accumulation rate of participants in the Registry by type during this period.

FIGURE 3 ACCUMULATION RATE OF PARTICIPANTS IN THE REGISTRY BY PATIENT TYPE FROM FEBRUARY 2012 TO 30 JUNE 2018

Feb 2012BSR Pilot began

Jul 2014National roll-out

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

Num

ber o

f pat

ient

s

2012 2013 2014 2015 2016 2017 2018

Primary − Gastric banding (LAGB) patients

Primary − Sleeve gastrectomy (LSG) patients

Legacy patients

Primary − Other patients


The BSR has captured 51,277 procedures from 47,649 participants since 2012 from across Australia and New Zealand. Less than 4% of bariatric patients chose to opt out of the registry.

14 Bariatric Surgery Registry 2017/18 Report

Procedures Captured by the Registry

Overview

In total, the Registry has captured 51,277 procedures performed on 47,575 participants (this excludes 74 participants who have only had an abandoned procedure). The Registry has captured 121 abandoned procedures since February 2012 with 41 of abandon procedures occurring in the last FY 17/18.

Table 2 below demonstrates the total capture of procedures by the Registry as at 30 June 2018 and the FY 17/18. The Registry successfully captured 17,716 of the 27,308 procedures recorded by the MBS. This accounts for 64.9% of MBS procedures captured in the Registry for the FY 17/18.

TABLE 2: PROCEDURES PERFORMED BY TYPE

Total BSR (Feb 2012 to 30 June 2018)

BSR FY 17/18 (1 July 2016 to 30 June 2018)

MBS Data FY 17/18

(Est of % collected in brackets)Primary Revision Total Primary Revision Total

Sleeve gastrectomy (LSG) 28,772 2,794 31,566 11,816 974 12,790 19,349 (66%)

Gastric Banding (LAGB) 5,197 1,567 6,764 591 215 806 1,098 (73%)

R-Y Gastric Bypass (RYGB) 2,258 2,521 4,779 865 869 1,7343,354 (82%)One anastomosis gastric bypass

(OAGB)1,408 844 2,252 661 356 1,017

Surgical Reversals of Bands - 4,476 4,476 - 1,369 1,369 NA

Other Procedures 130 1,310 1,440 74 448 552 NA

Total Procedures (excl Abandon) 37,765 13,512 51,277 14,007 4,231 18,238 NA

Abandoned Procedures 76 45 121 29 12 41 NA

The types of procedures captured by the Registry have evolved over the years. There has been an increase in LSG procedures from 49.2% in the FY 14/15 to 70.1% in the FY 17/18. One decrease that has been noticeable is that of the LAGB where the Registry had captured 26.4% in FY 14/15 and now has a rate of 4.4% in the FY 17/18. Figure 4 illustrates the changes the Registry has observed over the reporting years and the trends detailed above.


FIGURE 4 CHANGE IN PROCEDURE TYPE CAPTURED BY REGISTRY

FIGURE 5 PROCEDURES CAPTURED BY THE REGISTRY BY STATE AND PROCEDURE TYPE (FY 17/18)


Figure 6 below indicates the procedures captured by state for both private and public hospitals during the last financial year. Although there has been improvements in capture rates across Australia, Victoria remains the Registry’s strongest contributor for public hospitals.

FIGURE 6 PRIMARY PROCEDURES CAPTURED BY THE REGISTRY BY STATE AND PUBLIC/PRIVATE (FY 17/18)

Note: N = number of primary procedures in FY 17/18. Abandoned procedures are excluded. Two RYGB primary procedures were also captured for one New Zealand Private Site.

FIGURE 7 REVISION PROCEDURES CAPTURED BY THE REGISTRY BY STATE AND PUBLIC/PRIVATE (FY 17/18)

Note: N = number of revision procedures in FY 17/18. Abandoned procedures are excluded.


Since 2014, the Registry has measured its procedure capture rates against that of the MBS. Whilst MBS is not an accurate reflection of the total number of bariatric procedures performed as it does not include public hospital separations and if two procedure codes are used for the one operation (for example a reversal and reinsertion of a band) two procedures are captured rather than one, the numbers recorded on the MBS are a reasonable denominator for the BSR to track progress against.

For the FY 17/18 period, the Registry successfully captured 65% of MBS recorded procedures, which was a 16.9% increase rate from the previous financial year. Figure 8 illustrates the MBS capture growth for the Registry since 2014 whilst Table 3 below examines the MBS data capture by state for the FY 17/18.

FIGURE 8 MBS CAPTURE RATES FROM FY 13/14 TO FY 17/18*

* MBS data for LSG, LAGB, RYGB/OAGB and reversals only. Final figures of MBS data extracted on 10th August 2018

TABLE 3 PROCEDURES CAPTURED BY THE REGISTRY BY STATE (FY 17/18)*

NSW & ACT VIC QLD SA & NT WA TAS

MBS Data 8,430 4,474 7,708 1,604 4,661 431

MBS Data Captured by Registry 4,816 3,992 5,643 994 2,116 153

% MBS Data Captured by Registry 57% 89% 73% 62% 45% 35%

* MBS data for LSG, LAGB, RYGB/OAGB and reversals only. Final figures of MBS data extracted on 10th August 2018

Over the last 12 months, of procedures captured by the Registry 94.3% of primary procedures and 89.9% of revision procedures occurred at private hospitals across Australia and New Zealand. These statistics remain consistent with past reported trends for private and public procedure mix. Table 4 illustrates the procedures performed in public hospitals in Australia for both the last 12 months and since commencement in February 2012.


TABLE 4 PROCEDURES PERFORMED IN PUBLIC HOSPITALS IN AUSTRALIA

Total BSR (Feb 2012 to 30 June 2018)

BSR Last 12 months (1 July 2017 to 30 June 2018)

Primary in Public Revision in Public Primary in Public Revision in Public

# % of That Procedure

Type


Type


Type


Type

Sleeve gastrectomy (LSG) 2,207 7.7% 245 8.8% 601 5.1% 60 6.2%

Gastric Banding (LAGB) 824 15.9% 292 18.6% 68 11.5% 25 11.6%

R-Y gastric bypass (RYGB) 249 11.0% 227 9.0% 99 11.4% 57 6.6%

One anastomosis gastric bypass (OAGB)

57 4.0% 39 4.6% 22 3.3% 14 3.9%

Surgical Reversal NA NA 695 15.5% NA NA 184 13.4%

Other Procedures 17 13.1% 302 23.1% 8 10.8% 86 19.2%

Total Procedures 3,354 8.9% 1,800 13.3% 798 5.7% 426 10.1%

FIGURE 9 PRIMARY AND REVISION PROCEDURES CAPTURED BY THE REGISTRY IN PRIVATE VS PUBLIC HOSPITALS IN AUSTRALIA (FY 17/18)


Of the 51,277 primary and revision procedures captured, four procedures have reported to have had a concurrent renal transplant. There have been no reported liver transplants since February 2012.

TABLE 5 CONCURRENT RENAL TRANSPLANTS

Concurrent Renal Transplant with: Primary Bariatric Procedure Revision Bariatric Procedure

Financial Year 2017/2018 1 0

February 2012 to 30 June 2018 2 2

Primary Participants

Participants that undergo a primary procedure have quality and safety measured recorded peri-operatively as well as annual tracking of weight, diabetes status and treatments, any complications that have arisen including the need for reoperation. As at 30 June 2018, there were 37,765 primary procedures recorded in the Registry.

TABLE 6 PRIMARY PROCEDURES IN THE REGISTRY BY TYPE

DescriptionFY12/13 FY13/14 FY14/15 FY15/16 FY16/17 FY17/18

# % # % # % # % # % # %

Sleeve gastrectomy 18 2.7% 122 14.0% 2232 62.0% 6078 74.7% 8506 81.1% 11816 84.4%

Gastric banding 645 97.3% 732 83.9% 1051 29.2% 1265 15.6% 913 8.7% 591 4.2%

R-Y gastric bypass 0 0% 17 1.9% 255 7.1% 486 6.0% 635 6.1% 865 6.2%

One anastomosis gastric bypass

0 0% 0 0% 54 1.5% 288 3.5% 405 3.9% 661 4.7%

Gastric imbrication 0 0% 0 0% 0 0 0 0% 1 0% 2 0%

Gastric imbrication, plus gastric band (iBand)

0 0% 0 0% 5 0.1% 4 0% 2 0% 0 0%

Gastroplasty 0 0% 0 0% 1 0% 3 0% 0 0% 14 0.1%

Bilio pancreatic bypass/duodenal switch

0 0% 1 0.1% 1 0% 10 0.1% 23 0.2% 17 0.1%

Other (specify) 0 0% 0 0% 0 0% 0 0% 5 0% 37 0.3%

Not stated/inadequately described

0 0% 0 0% 0 0% 0 0% 0 0% 4 0%

TOTAL 663 100% 872 100% 3599 100% 8134 100% 10490 100% 14007 100%


Of the 37,765 primary participants in the Registry, 2.6% have gone on to have one or more revision procedures as shown in Table 7 below.

TABLE 7 NUMBER OF PROCEDURES UNDERGONE BY PARTICIPANTS FROM FEBRUARY 2012 TO 30 JUNE 2018

Primary Participants who have had: Number %

Only an Abandoned Procedure 42 NA

Only a Primary Procedure 36,773 97.4%

A Primary Procedure & 1 Revision 788 2.1%

A Primary Procedure & 2 Revisions 154 0.4%

A Primary Procedure & 3 Revisions 33 0.1%

A Primary Procedure & 4 Revisions 8 0%

A Primary Procedure & 5 Revisions 6 0%

A Primary Procedure & more than 5 revisions 3 0%

TOTAL PRIMARY PARTICIPANTS* 37,765 100%

* Excludes those participants with only an abandon procedure

Revision incidence rates are analysed by calculating the time between the primary bariatric procedure and the first revision procedure and are demonstrates in Figure 10 below. To analyse this data, survival analysis techniques were used4. The Nelson‐Aalen cumulative probability estimates show a low revision incidence rate of bariatric procedures. At one-year post primary procedure, 1.4% (95% CI 1.3% to 1.5%) of participants are estimated to have had their first revision procedure. At two years post primary procedure, 2.7% (95% CI 2.5% to 2.9%) are estimated to have had their first revision procedure.

FIGURE 10 REVISION INCIDENCE RATES FOR PRIMARY BARIATRIC PROCEDURES AS AT 30 JUNE 2018

0%

2%

4%

6%

8%

10%

12%

14%

16%

Cum

ulat

ive

Rev

isio

n In

cide

nce

Rat

e

0 1 2 3 4 5

Years Between Primary Bariatric Procedure and First Revision

37,765 24,040 13,123 5,005 1,339 536 Number at risk

95% Confidence Interval

All Primary Patients


Of the 37,765 primary procedures recorded, 97.4% of participants have had no recorded revisions. Tables 8a, b, c and d explore the four main primary procedure types and revisions that have occurred as at 30 June 2018.

TABLE 8A CURRENT STATUS OF SLEEVE GASTRECTOMY PRIMARY PARTICIPANTS AS AT 30 JUNE 2018

No. of Sleeve Gastrectomy Primary Participants who currently have:

Only a Primary LSG 28,559

Any Revision of LSG 213

- Conversion to RYGB 77

- Conversion to OAGB 14

- Required just Lavage 19

- Required just Dilitation 17

- Other Revision 86

Total 28,772

TABLE 8B CURRENT STATUS OF GASTRIC BANDING PRIMARY PARTICIPANTS AS AT 30 JUNE 2018

No. of Gastric Band Participants who currently have:

Only a Primary Gastric Band 4,530

Any Revision of Band 667

- Port Revision 214

- Band Revision 130

- Band Reversal 164

- Conversion to LSG 86



- Other Revision(s) Required 9

Total 5,197

TABLE 8C CURRENT STATUS OF RY GASTRIC BYPASS PRIMARY PARTICIPANTS AS AT 30 JUNE 2018

No. of RY Gastric Bypass Primary Participants who currently have:

Only a Primary RYGB 2,171

Any Revision of RYGB 87

- Revision of RYGB 10


- Conversion to LSG 2

- Required just Dilitation 24


Total 2,258

TABLE 8D CURRENT STATUS OF ONE ANASTOMOSIS GASTRIC BYPASS PRIMARY PARTICIPANTS AS AT 30 JUNE 2018

No. of One Anastomosis Gastric Bypass Primary Participants who currently have:

Only a Primary OAGB 1,389

Any Revision of OAGB 19



Total 1,408


Legacy Participants

Legacy participants have the quality and safety measures recorded peri-operatively but do not have annual follow ups. As at 30 June 2018, there were 9,810 legacy participants recorded in the Registry.

Further revision procedures have been recorded for 2,175 Legacy Participants (22.2%). Compared to the primary participant cohort there is a higher rate of further revision procedures but this statistic is reflective of the complexity of the revision surgery.

TABLE 9 NUMBER OF PROCEDURES UNDERGONE BY LEGACY PARTICIPANTS FROM FEBRUARY 2012 TO 30 JUNE 2018

# Legacy Participants who have had: Number %

Only an Abandoned Revision Procedure 32 NA

Only One Revision Procedure 7,635 77.8%

2 Revision Procedures on BSR 2,022 20.6%

3 Revision Procedures on BSR 119 1.2%



More than 5 Revision Procedures on BSR 4 0.0%

TOTAL LEGACY PARTICIPANTS* 9,810 100%

* excludes those participants with only an abandoned procedure

Demographics

True to observations throughout the years from the Registry, bariatric procedures are performed predominately on female participants. As at 30 June 2018, there were 37,642 (79%) females, 9,919 (21%) males and 14 (0.03%) intersex and/or indeterminate persons enrolled in the Registry who have had a procedure.

The distribution of gender in primary and revision procedures also shows a similar trend where females account for 78% of all primary procedures and 84% of revision procedures, males account for 22% of primary procedures and 16% of revision procedures and intersex and/or indeterminate persons account for 0.03% of primary procedures.

Table 10 demonstrates the key demographic indicators of participants enrolled in the Registry that have had a procedure in the last financial year (2017/2018 year). The contents of this table compares primary and revision procedures as well as private and public hospital procedures.

The mean age for all procedures was 44.1 years old and as observed below, both female (42.1) and male (44.7) participants with primary procedures have a lower mean age than the female (48.2) and male (51.2) participant group with revision procedures. For primary participants, males are older age than females (+ 3.2 years), a slightly higher BMI (+ 0.9) and have a high incidence of diabetes at the time of operation. For primary participants, the difference in age and BMI is statistically significant.


TABLE 10 DEMOGRAPHICS OF PARTICIPANTS AT THEIR PROCEDURE (FY 17/18)

Primary Procedures Revision Procedures Total Procedures

Public Private All Public Private All Public Private All

Procedure Number 798 13,209 14,007 426 3,805 4,231 1,224 17,014 18,238

Females undergoing procedure

637 10,294 10,931 367 3,190 3,557 1,004 13,484 14,488

80% 78% 78% 86% 84% 84% 82% 79% 79%

Males undergoing procedure

161 2,911 3,072 59 613 672 220 3,524 3,744

20% 22% 22% 14% 16% 16% 18% 21% 21%

Indeterminate gender undergoing procedure

0 4 4 0 2 2 0 6 6

Mean Age at Op 43.8 42.6 42.7 48.3 48.7 48.7 45.4 44.0 44.1

Mean Age at Op - Female 43.6 42.0 42.1 47.9 48.2 48.2 45.2 43.5 43.6*

Mean Age at Op - Male 44.7 44.7 44.7 50.3 51.3 51.2 46.2 45.9 45.9*

Min Age at Op 17.0 13.7 13.7 23.1 17.7 17.7 17.0 13.7 13.7

Min Age at Op - Female 17.0 13.7 13.7 23.1 17.7 17.7 17.0 13.7 13.7

Min Age at Op - Male 17.1 15.9 15.9 26.7 21.3 21.3 17.1 15.9 15.9

Max Age at Op 83.5 82.6 83.5 72.6 86.1 86.1 83.5 86.1 86.1

Max Age at Op - Female 83.5 78.8 83.5 72.6 83.1 83.1 83.5 83.1 83.5

Max Age at Op - Male 71.1 82.6 82.6 69.7 86.1 86.1 71.1 86.1 86.1

Mean BMI at Op 44.8 42.4 42.5 41.3 39.8 40.0 43.7 41.7 41.9

Mean BMI at Op - Female 44.8 42.1 42.3 40.9 39.5 39.7 43.5 41.4 41.6**

Mean BMI at Op - Male 44.7 43.3 43.4 43.7 41.4 41.6 44.5 43.0 43.1**

Max Weight at Op (Kg) 233 300 300 224 300 300 233 300 300

Max Weight at Op - Female (Kg)

233 240 240 176 300 300 233 300 300

Max Weight at Op - Male (Kg)

219 300 300 224 276 276 224 300 300

% Diabetes at baseline 25.3 13.4 14.5

% Diabetes at baseline - Female

22.2 11.3 13.4

% Diabetes at baseline - Male

36.1 19.9 21.4

* p-value < 0.001 (Two-sample t-test) statistically significant difference in mean age at operation between males and females ** p-value < 0.001 (Two-sample t-test) statistically significant difference in mean BMI at operation between males and females


Figure 11 and 12 below illustrate the age range of both primary and revision participants at the time of procedure during the last financial year (2017/2018)

FIGURE 11 PARTICIPANTS’ AGE DISTRIBUTION AT TIME OF PRIMARY PROCEDURE (FY 17/18)

FIGURE 12 PARTICIPANTS’ AGE DISTRIBUTION AT TIME OF REVISION PROCEDURE (FY 17/18)

0.0

0.4

1.7

4.4

8.3

11.3

14.5

15.0

14.5

12.8

10.1

5.6

1.3

75+

70−74

65−69

60−64

55−59

50−54

45−49

40−44

35−39

30−34

25−29

20−24

<20

N = 10,931

Female (%)

0.3

1.1

3.0

5.7

10.1

13.2

15.8

15.7

12.9

11.2

6.7

3.3

1.0

75+

70−74

65−69

60−64

55−59

50−54

45−49

40−44

35−39

30−34

25−29

20−24

<20

N = 3,072

Male (%)

Age at Primary Procedure (Years)

0.3

1.7

4.6

8.2

13.6

15.5

18.4

13.5

10.4

8.4

4.0

1.1

0.1

75+

70−74

65−69

60−64

55−59

50−54

45−49

40−44

35−39

30−34

25−29

20−24

<20

N = 3,557

Female (%)

0.6

2.5

6.8

13.1

16.7

13.4

20.5

10.6

8.6

3.4

2.5

1.2

75+

70−74

65−69

60−64

55−59

50−54

45−49

40−44

35−39

30−34

25−29

20−24

<20

N = 672

Male (%)

Age at Revision Procedure (Years)


Similarly, with weight at the time of procedure, those participants undergoing a primary procedure will typically have a higher weight at operation than those participants undergoing a revision procedure. Figure 13 explores this relationship below.

FIGURE 13 PARTICIPANTS’ WEIGHT AT TIME OF PROCEDURE (FY 17/18)

Follow Up

Demonstrated in Table 11 are the follow up rates achieved at each data point by the Registry. Data is defined as “due” on the appropriate anniversary from the date of the operation where the peri-operative follow up data is due 30 days after the operation date, year 1 data is due one year after the surgery date and so on.

Within the Registry’s, 5,739 (6%) of follow ups were not collected as the Participant could not be contacted and this represents 5,005 (9.9%) participants and are recognised as Lost to follow Up (LTFU). LTFU indicates that participants are no longer followed up for peri-operative and/or annual data for the procedure they were originally enrolled in the Registry for. However, a patient will be contacted again if they undergo another bariatric procedure for the collection of follow up data relating to that procedure.

The Registry’s Call Centre have completed 11,686 follow up calls for 6,515 (7.1%) participants from February 2012 to 30 June 2018.

0%

5%

10%

15%

20%

Perc

enta

ge o

f Pro

cedu

res

30 60 90 120 150 180 210 240 270 300

Operation Weight (kgs)

Primary procedures (N = 10,680)Revision procedures (N = 3,651)


TABLE 11 FOLLOW UP COMPLETION BY TYPE^

PERI-OP YEAR 1 YEAR 2 YEAR 3 YEAR 4 YEAR 5 YEAR 6 TOTAL

Total Follow Ups 49,952 23,595 12,031 4,175 1,271 511 60 91,595

Total Complete with Data 41,008 16,178 6,852 2,345 857 285 22 67,547

% Complete with Data 82% 69% 57% 56% 67% 56% 37% 74%

Total Outstanding 7,313 5,146 3,814 1,504 315 181 36 18,309

% Outstanding 15% 22% 32% 36% 25% 35% 60% 20%

Awaiting BSR to Call for Follow Up 1,405 1,432 1,133 431 115 70 0 4,586

% Awaiting BSR to Call for Follow Up 19% 28% 30% 29% 37% 39% 0% 25%

Total Lost to Follow Up 1,631 2,271 1,365 326 99 45 2 5,739

% Lost to Follow Up 3% 10% 11% 8% 8% 9% 3% 6%

^ Australia and New Zealand peri-operative and annual follow up data has been combined for this report due to the low enrolment numbers for New Zealand. Future annual reports will allow for the distinction between Australia and New Zealand for follow up statistics.

Improving follow up rates will be a major focus of the Registry in the next 12 months.

Safety Reporting

Deaths

Deaths are rare in the Registry but as a longitudinal registry, there is an expectation that reporting the death of some participants will occur. Causes of death vary considerably and the Registry ensures through Coroner’s reports and/or autopsy reports that confirmation of cause of death is received prior to attributing the death to be likely related to the bariatric procedure. Since our last Annual Report as at 30 June 2017, there has been a further twenty-four (24) reported deaths.

There is now 46 participants reported as deceased in the Registry (0.09% of total participants). Of the 46 deaths reported, 16 are confirmed cases where death was not related to the bariatric procedure whilst 24 cases are yet to be determined.

Table 12 and 13 below outline the total number of deaths reported and the cause of death for those cases that were likely related to the bariatric procedure in Australia. As at 30 June 2018 there were no recorded deaths of New Zealand participants.

TABLE 12 – DEATHS REPORTED TO THE REGISTRY UP TO 30 JUNE 2018

As at 30 June 2018

Unrelated to procedure 16 (35%)

Likely related to procedure 6 (13%)

Not yet determined 24 (52%)

TOTAL 46


TABLE 13 – CAUSE OF DEATH WHEN DEATH WAS LIKELY RELATED TO BARIATRIC PROCEDURE AS AT 30 JUNE 2018

Date of Death Patient Group Procedure Cause of Death

Q1 2014 Legacy LAGB to LSG Staple line leak

Q4 2014 Primary SAGB Anastomotic leak, multi organ failure

Q1 2015 Primary RYGB Anastomotic leak, multi organ failure

Q4 2015 Legacy RYGB Fistula track

Q4 2015 Primary LAGB Sepsis

Q1 2017 Primary RYGB Complications of bariatric surgery, pulmonary embolism

Peri-Operative Defined Adverse Events and Complications

As at 30 June 2018, there have been 1,615 Defined Adverse Events reported to the Registry from 1,359 procedures in Australia. For procedures with completed peri-operative data, it is possible to have more than one Defined Adverse Event recorded. These Events resulted from procedures performed on 1,164 participants (723 of primary participants and 441 of legacy participants) and the data was recorded within the peri-operative window (up to 90 days post-operative).

There have been no Defined Adverse Events recorded for New Zealand participants as at 30 June 2018.

TABLE 14 – DEFINED ADVERSE EVENTS IN ALL PARTICIPANTS UP TO 30 JUNE 2018

Resulting In Primary Procedures Revision Procedures All Procedures

Unplanned Return to Theatre 357 480 837

Unplanned Admission to ICU 42 36 78

Unplanned Re-admission to Hospital 412 288 700

Any Defined Adverse Event 679 680 1,359

Tables 15 and 16 demonstrate the incidence of Defined Adverse Events by both primary and revision procedures from 1 July 2017 to 30 June 2018.

TABLE 15 – PRIMARY PROCEDURES BY TYPE WITH A DEFINED ADVERSE EVENT (FY 17/18)

Primary ProceduresNo. Procedures with Any Defined Adverse

Event

Total No. Procedures with Peri-Op Follow Up

Percentage with a Defined Adverse Event

Sleeve Gastrectomy (LSG) 137 7,383 1.9%

Gastric Banding (LAGB) 7 366 1.9%

R-Y Gastric Bypass (RYGB) 52 587 8.9%

One Anastomosis Gastric Bypass (OAGB) 15 462 3.2%

Other Primary Procedures 1 37 2.7%

TOTAL 212 8,835 2.4%


TABLE 16 – REVISION PROCEDURES BY TYPE WITH A DEFINED ADVERSE EVENT (FY 17/18)

Revision ProceduresNo. Procedures with Any Defined Adverse

Event

Total No. Procedures with Peri-Op Follow

Up

Percentage with a Defined Adverse

Event

Sleeve Gastrectomy (LSG) 16 575 2.8%

Gastric Banding (LAGB) 7 94 7.4%

R-Y Gastric Bypass (RYGB) 66 596 11.1%

One Anastomosis Gastric Bypass (OAGB) 14 204 6.9%

Port Revision 11 76 14.5%

Reversal of Gastric Band 13 791 1.6%

Lavage/washout ± drainage 6 9 66.7%

Stent (insertion or removal) 1 2 50.0%

Dilitation 11 25 44.0%

Division of Adhesions 6 18 33.3%

Control of Post-Operative Bleed 3 7 42.9%

Other Revision Procedures 9 74 12.2%

TOTAL 163 2,471 6.6%

One complication can lead to more than one Defined Adverse Event and a patient may experience multiple complications causing a single Defined Adverse Event. It is because of this there is not a one to one relationship between the number of complications and the number of Defined Adverse Events recorded.

The complications attributing to a Defined Adverse Events are displayed in Figure 14. The “other” category accounts for 35.5% of complications recorded. The “other” category has been greatly refined from past reporting and over the past financial year there has been 18 new categories made available to the dataset to ensure that an accurate complications outcome were reported.


FIGURE 14 – REASONS ATTRIBUTED FOR DEFINED ADVERSE EVENTS IN ALL PARTICIPANTS (FY 17/18)

Figure 15 outlines the complications detailed during the annual follow up data collection (data collection period: 1 July 2017 to 30 June 2018) as to why a revision procedure has occurred and the complications that had arisen resulting in a revision procedure from.

FIGURE 15 – REASONS ATTRIBUTED FOR REOPERATION ON PRIMARY PARTICIPANTS (FY 17/18)


Weight Outcomes

The start BMI for participants undergoing primary procedures was 44.1 (st dev 7.9) with a mean BMI of 42.8 (st dev 7.4) on the day of surgery. Figure 16 illustrates the variation of obesity classifications represented in the Registry from February 2012 to 30 June 2018 and highlights the trend in the cohort’s BMI and classification distribution. This cohort consists of 22,825 primary participants where both start weight, height and day of surgery weight has been captured.

FIGURE 16 START BMI AND DAY OF SURGERY BMI CLASSIFICATION FOR PRIMARY PARTICIPANTS FROM FEBRUARY 2012 TO 30 JUNE 2018 (N=22,825).


Table 17 demonstrates the differences in start BMI compared to day of surgery BMI, as well as comparing male, female, private, and public variations. Interestingly, there are clear differences in these comparisons, which warrant further investigations.

TABLE 17 MEAN BMI FOR ALL PRIMARY PROCEDURES FROM FEBRUARY 2012 TO 20 JUNE 2018

WEIGHT MEASURE FEMALE MALE ALL

Mean Start BMI 43.8 45.1 44.1

(Standard Deviation) 7.8 8.0 7.9

Mean DOS BMI 42.5 43.6 42.8


Mean Start BMI – Public 47.6 49 47.9


Mean DOS BMI – Public 46 46.7 46.2


Mean Start BMI – Private 43.4 44.8 43.7


Mean DOS BMI – Private 42.1 43.2 42.4


There are 13,582 primary participants who were over 18 years old at the time of the procedure and their weight at 12 months has been captured. Their mean BMI at this 12 month mark was 32.2 (st dev 7.0), their mean Excess Weight Loss (EWL) is calculated as 66.4% and their mean Total Weight Loss (TWL) is 26.5%.

TABLE 18 WEIGHT OUTCOMES AT 12 MONTHS FOR ALL PRIMARY PROCEDURES FROM FEBRUARY 2012 TO 30 JUNE 2018

WEIGHT MEASURE ALL*

Mean BMI at 12 Months 32.2

(Standard Deviation) 7.0

Mean EWL at 12 Months 66.4%


Mean TWL at 12 Months 26.5%


* Excludes participants under 18 years of at the time of the primary procedure

The Registry successfully collected 3 years of follow up data on 1,638 primary participants and from this cohort the EWL at Year 3 was 53.2% and the TWL at Year 3 was 21.4%. Figure 17 shows the EWL and TWL plots for all primary participants where the Registry has obtained 3 years of follow up data.


FIGURE 17 EXCESS WEIGHT LOSS AND TOTAL WEIGHT LOSS FOR PRIMARY PARTICIPANTS WHO HAVE REACHED 3 YEAR ANNUAL FOLLOW UP (N=1,638)

The Registry successfully collected 4 years of follow up data on 613 primary participants and from this cohort the EWL at Year 4 was 49.1% and the TWL at Year 4 was 19.5%. Figure 17 shows the EWL and TWL plots for all primary participants where the Registry has obtained 4 years of follow up data.

FIGURE 18 EXCESS WEIGHT LOSS AND TOTAL WEIGHT LOSS FOR PRIMARY PARTICIPANTS WHO HAVE REACHED 4 YEAR ANNUAL FOLLOW UP (N=613)


Diabetes Outcomes

At 30 June 2018, the Registry successfully obtained diabetes at baseline results for 37,765 primary participants with 5,467 (14.5%) of this cohort indicating that they have diabetes at the time of the primary procedure. As observed in previous reports and as demonstrated in Table 19, males tend to have a higher incidence of diabetes at time of procedure than females and there is a higher incidence of diabetes amongst the public participants than in private participants.

TABLE 19 PRIMARY PARTICIPANTS IDENTIFYING AS HAVING DIABETES AT BASELINE FROM FEBRUARY 2012 TO 30 JUNE 2018

FEMALE MALE ALL

Public 22.2% 36.1% 25.3%

Private 11.6% 19.9% 13.4%

All 12.5% 21.4% 14.5%

The treatment prescribed to this patient cohort at baseline are detailed in Table 20 below where the two largest groups of treatment are non-insulin (mono therapy) which accounts for 34.3% of the cohort and diet and exercise which accounts for 20.6%. Interestingly, the female cohort has a higher rate of diet and exercise and non-insulin (mono) therapy as baseline treatment than males. Males have higher incidence rates of non-insulin (poly) therapy and insulin as treatment at baseline than females.

TABLE 20 TREATMENT FOR DIABETES AT BASELINE FROM FEBRUARY 2012 TO 30 JUNE 2018

TREATMENT FOR DIABETES FEMALES MALES ALL

Diet/Exercise 842 23% 282 15.6% 1,124 20.6%

Non-Insulin (mono) Therapy 1,324 36.1% 551 30.6% 1,875 34.3%

Non-Insulin (poly) Therapy 505 13.8% 349 19.4% 854 15.6%

Insulin 686 18.7% 460 25.5% 1,146 21%

Not Stated 308 8.4% 160 8.9% 468 8.6%

TOTAL 3,665 100% 1,802 100% 5,467 100%


Figure 19 illustrates the entire primary patient cohort that have indicated diabetes and the treatment that was recorded at baseline. Interestingly, there is no statistical difference amongst the treatment options.

FIGURE 19 PRIMARY PARTICIPANTS IDENTIFYING AS HAVING DIABETES AND TREATMENT AT PRIMARY PROCEDURE FROM FEBRUARY 2012 TO 30 JUNE 2018 (N=37,765 PRIMARY PARTICIPANTS)

The Registry has successfully collected annual follow up data for 2,764 of these primary participants. The variation between baseline treatments to 12-month follow up treatment is demonstrated in Table 21 below.

TABLE 21 TREATMENT OF PARTICIPANTS WITH DIABETES REPORTED AT BASELINE FOLLOWED UP AT 12 MONTHS

TREATMENT FOR DIABETES BASELINE AT 12 MONTHS

Diet/Exercise 531 19.2% 230 8%

Surgery Alone NA NA 1,060 38%

Non-Insulin (mono) Therapy 967 35% 311 11%

Non-Insulin (poly) Therapy 385 13.9% 57 2%

Insulin 621 22.5% 177 6%

Not Stated 260 9.4% 624 23%

Lost to Follow Up NA NA 305 11%

TOTAL 2,764 100% 2,764 100%

* The Registry has commenced distinguishing between “Not Stated” and “Lost to Follow Up” to ensure each category is a true reflection of data capture.

Twelve months after surgery, 46% of this cohort no longer require treatment for diabetes, as demonstrated by the “Surgery alone” and/or “Diet/Exercise” categories. The proportion of participants requiring insulin has decreased from 22% at baseline to 6% at 12 months post-surgery however treatment outcomes at 12 months post-surgery is not known for 23% of the cohort.


CONCLUSION

Over the past 12 months, there has been significant growth in the numbers of participants enrolled in the Registry. The Registry now has good coverage across most states and territories with an excellent uptake from hospitals and clinicians alike.

The data to date confirms the safety and efficacy of bariatric surgery although data must be interpreted with caution until the entire population is captured and follow up rates improved.

The numbers of procedures performed around Australia continues to grow at a rapid pace. In this setting, it is more critical than ever that we monitor our outcomes and constantly seek to improve the care we provide our participants. Over the next 6 months, we will be striving to achieve complete total enrolment of hospitals and surgeons across Australia. One of the key focuses for the Registry will be endeavouring to capture a minimum of 81% of procedures recorded annually in the MBS.

Over the past 6 months, we have welcomed the first of the participating sites in New Zealand into the Registry along with the first of the enrolled participants. We look forward to obtaining governance approvals for all 20 sites in New Zealand in the next 12 months and growing into the bi-national registry.

Into the new financial year and the Registry will be implementing a new website with a participant portal for the capture of follow up data via a SMS link, the expansion of PROMs to focus on diabetes and health economics as well as psychosocial trends and the enhancement of data capture methods through data linkages and collaborations.

We sincerely thank the surgeons, hospitals, industry and government for their ongoing support to the Registry. We look forward to presenting the bariatric surgery activity across Australia and New Zealand over the next year and improving the strength and coverage of the Registry.


ACKNOWLEDGEMENTS

AUSTRALIA

We would like to thank the Commonwealth Government of Australia (Department of Heath) for their support of the BSR pilot and rollout. We would also like to thank our other funders for their on-going support: Applied Medical, Medtronic and Gore Medical. Their commitment to best quality care is much appreciated.

Many thanks to the staff of the BSR who make not only this report but the BSR possible. This year we have welcomed a new Programme Manager Brooke Backman who has made an outstanding contribution already. We farewelled our Project Manager Dianne Brown after 4-years. It is not an exaggeration to say that without her expertise we would not have a BSR today. Dana Briggs was with us for a short but productive time and she was instrumental in helping us to secure ongoing Commonwealth funding. Our long-serving staff Data Manager Aileen Heal, Customer Relationship Manager Jenifer Cottrell, our Administrative Officer Marlene Jacobs, Database Support Officer Adrian Heal and Data Operations Analyst Sonya Palmer all do an incredible job and we are so lucky to have such a strong team.

We could not function without our data entry and call centre staff. These are currently Alli Holt, Eddy Woldemareyam, Jazz Padarath, Nilab Hamidi, Seba Joseph, Tiasha Fernando, TJ Muhlen-Schulte, Pari D’Cruz, Alex Lukacz, Rebecca Argento and Henry Truong. Thank you for your careful work ensuring our data is of the highest quality.

The Monash University Registry Sciences Unit provide us with the expertise necessary to ensure that these data are collected, stored and analysed according to rigorous standards. Many thanks to John McNeil, Breanna Pellegrini, Arul Earnest and Susannah Ahern for all of your support.

Our Steering Committee provides expert advice and support. Every member has freely provided their expertise and we value the strength of the governance this process provides. Particular thanks go to our Chair, Professor Ian Caterson. His enthusiasm, knowledge and wise counsel is much appreciated.

It would be remiss of me not to acknowledge the considerable effort that every bariatric surgeon in Australia, their teams and the participating hospital sites have put into the establishment of the BSR. It is extra work and it is time consuming. Despite our best efforts to streamline this and minimise the impact of practice, it cannot be denied that participation in the registry adds to an already busy work life. Despite this, the BSR remains a priority for the overwhelming majority of bariatric surgeons and we are encouraged by their enthusiasm and goodwill.

Most importantly, thank you to our participants who generously share their information with us to improve the quality of Bariatric Surgery in Australia. We are indebted to each and every one of you!

Professor Wendy Brown MBBS (hons) PhD FACS FRACS Clinical Director BSR Clinical Lead, Australia

NEW ZEALAND

We would like to thank our funders for their on-going support: Applied Medical, Medtronic and Gore Medical. Their commitment to best quality care is much appreciated. Their funding has allowed the establishment and rollout of the BSR in Aotearoa New Zealand.

We could not have started in Aotearoa New Zealand without the support of the staff at National Institute of Health Innovation (NIHI), University of Auckland. Thanks to Anna-Marie Rattray, Karen Carter, Nick Kearns and Professor Chris Bullen. Thank you for your dedication to get this project off the ground.

I would also like to acknowledge the considerable effort that every bariatric surgeon in Aotearoa New Zealand, their teams and the participating hospital sites have put into the establishment of this Registry.

We acknowledge the extra work, it is time consuming, yet the universal enthusiasm to make the BSR work has been amazing. Thank you so much for making the BSR possible. It is so heartening to see how committed we all are as a bariatric surgical community to improving the quality of the care we provide our patients.

Finally thank you to our participants who generously share their information with us to improve the quality of Bariatric Surgery. We are indebted to all of you!

Associate Professor Andrew MacCormick BHB MBChB PhD FRACSClinical Lead Aotearoa New Zealand


COMMITTEES AND STAFF

STEERING COMMITTEE MEMBERS

Prof Ian Caterson Committee Chair Prof Wendy Brown Deputy Chair, BSR Clinical Director, ANZMOSS Representative Assoc. Prof Andrew MacCormick NZ Clinical Lead, ANZMOSS RepresentativeMs. Brooke Backman BSR Programme Manager Prof John McNeil BSR Data Custodian, SPHPM Head of DepartmentDr. Susannah Ahern Monash University Registry Science UnitMs. Helen Wing Department of Health Commonwealth Government Mr. Nathan Hyson Department of Health Commonwealth GovernmentDr. Samuel Baker ANZMOSS RepresentativeProf Paul O’Brien ANZMOSS RepresentativeProf Neil Merrett ANZGOSA RepresentativeProf Chris Bullen NIHI RepresentativeMs. Meron Pitcher Independent RACS Representative Assoc. Prof Arul Earnest Senior Biostatistician, Monash University Registry Science UnitMr. Edwin Ho MTAA Representative Ms. Corinna Musgrave Community Representative

CLINICAL LEADS

Professor Wendy Brown (Australia) Associate Professor Andrew MacCormick (New Zealand)

BSR STAFF – AUSTRALIA

Prof Wendy Brown BSR Clinical Director Ms. Dianne Brown BSR Consultant Ms. Brooke Backman Programme ManagerDr. Jenifer Cottrell Customer Relationship ManagerMs. Aileen Heal Data ManagerMs. Marlene Jacobs Administration OfficerMr. Adrian Heal Database Support OfficerMs. Sonya Palmer Data Operations AnalystMr. Pari D’Cruz Technical Officer Mr. Henry Truong Technical Officer Mr. Alex Lukacz Technical OfficerMs. Rebecca Argento Technical OfficerMs. Jazmin Padarath Administration Assistant (Data Entry)Ms. Tjuntu Muhlen-Schulte Administration Assistant (Data Entry)Ms. Eddy Woldemareyam Administration Assistant (PFS Statements)Ms. Nilab Hamidi Administration Assistant (Ethics)Ms. Alli Holt Administration Assistant (Call Centre)Ms. Seba Joseph Administration Assistant (Call Centre)Ms. Tiasha Fernando Administration Assistant (Call Centre)

BSR STAFF – NEW ZEALAND

Assoc. Prof Andrew MacCormick BSR Clinical LeadKristin Sutherland Project ManagerMs. Anna-Marie Rattray Research Assistant


APPENDIX 1: DATA ELEMENTS CAPTURED

Day of surgery Perioperative Follow Up

Name Date of follow up

Date of Birth Mortality

Gender If yes –

Address Date of death

Phone Numbers Cause of death

Medicare & DVA Information Death related to procedure?

Hospital UR number Defined Adverse Event

Name of Hospital & State Unplanned return to theatre

Indigenous status Unplanned ICU admission

Date of Surgery Unplanned re-admission to hospital

Weight – Day decision made to undergo surgery If yes – Reason

Weight – Day of Surgery BSR to follow up

Height

Diabetes Status Annual Follow Up*

Diabetes Treatment Date of follow up

Diet/exercise; Weight

Non-insulin Therapy (mono) Diabetes Status

Non-Insulin Therapy (poly) Diabetes Treatment

Insulin Diet/exercise;

Status of Procedure (Primary vs Revision) Non-Insulin Therapy (Mono)

If Revision – Last Bariatric Procedure Non-Insulin Therapy (Poly)

If Revision – Planned or Unplanned Insulin

If Unplanned – Reason Reoperation in last 12 months?

Procedure Abandoned vs Completed If yes – Reason

Type of Procedure Mortality

Device Type If yes –

Device Brand Date of death

Device Model Cause of death

If stapling – Buttress? Death related to procedure?

Concurrent Liver Transplant BSR to follow up

Concurrent Renal Transplant

* Primary Participants Only


APPENDIX 2: LIST OF SITES WITH ETHICS APPROVAL

Australia As at 30 June 2018

NSW

Albury-Wodonga Private Baringa Private Brisbane Waters Private Calvary Riverina Campbelltown Private Castle Hill Day Surgery Concord RGH Gosford Private Gosford Public Hospital for Specialist Surgery Hurstville Private John Hunter Kareena Private Lake Macquarie Private Lingard Private Mater Sydney Nepean Private Newcastle Private North Shore Private Norwest Private Nowra Private Port Macquarie Private Prince of Wales Private Royal North Shore Royal Prince Alfred Southern Highlands Private St George Private Strathfield Private Sydney Adventist Sydney South West Private Westmead Private

VIC

Austin Hospital Austin Repatriation Box Hill Hospital Cabrini Brighton Cabrini Malvern Epworth Eastern Epworth Freemason Epworth Geelong Epworth Richmond Essendon Private Footscray Hospital Geelong Private Glen Iris Private Hamilton Hospital Jessie McPherson Private John Fawkner Knox Private Latrobe Regional Linacre Private Maryvale Private Mildura Base Mildura Health Private Mitcham Private Monash Medical Centre Northpark Private Peninsula Private Shepparton Private St John of God Ballarat St John of God Bendigo St John of God Berwick St John of God Geelong St John of God Warrnambool St Vincent’s Private - Fitzroy St Vincent’s Public Sunshine Hospital The Alfre The Avenue The Valley Wangaratta Private Warringal Private Waverley Private Western Private Williamstown

QLD

Buderim Private Cairns Private Gold Coast Private Greenslopes Private Holy Spirit Northside Ipswich General John Flynn Private Kawana Private Mater Brisbane Mater North Queensland Mater Private (Brisbane) Mater Rockhampton Nambour Selangor Private Noosa Private North West Private (Brisbane) Pindara Private Princess Alexandra Queen Elizabeth II Jubilee Royal Brisbane St Andrew’s War Memorial St Andrew’s-Ipswich Private Sunnybank Private Sunshine Coast Uni Private The Wesley

SA

Ashford Private Calvary Central Districts Calvary North Adelaide Calvary Wakefield Flinders Medial Centre Flinders Private Queen Elizabeth Hospital Repatriation General

WA

Bethesda Hospital Glengarry Private Hollywood Private Joondalup Health Campus Mount Hospital St John of God Bunbury St John of God Geraldton St John of God Mt Lawley St John of God Murdoch St John of God Subiaco Waikiki Private

TAS

Calvary St Vincent’s Launceston Hobart Private Launceston General North West Private (Burnie) Royal Hobart

NT

Darwin Private

ACT

National Capital Private

New Zealand

Middlemore Hospital Southern Cross Christchurch Southern Cross Hamilton Southern Cross North Harbour Southern Cross Wellington St George’s Hospital


REFERENCES

1 Australian Parliament House of Representatives Standing Committee on Health and Ageing. Weighing it up : obesity in Australia, http:/ / www.aph.gov.au/ Parliamentary_Business/ Committees/ House_of_Representatives_Committees?url= haa/ ./ obesity/ report/ fullreport.pdf

2 Australian Medical Association, AMA Position Statement – Obesity 2016, https://ama.com.au/position-statement/obesity-2016

3 Ministry of Health. 2017. Annual Data Explorer 2016/17: New Zealand Health Survey [Data File]. URL: https://minhealthnz.shinyapps.io/nz-health-survey-2016-17-annual-update

4 Revision incidence rates can be analysed by calculating the time between primary bariatric procedure to the first subsequent revision procedure. Those patients with a primary procedure soon after February 2012 are observed for longer periods than those with a primary procedure later in the observation period. Survival analysis techniques (ie. Nelson Aalen method) estimate the probability of revision at each follow up time point based on the number at risk of revision and the number of revisions at that time point. This method censors patients that are revision free at the end of the observation period and truncates patients who have already experienced a revision prior to the observation period. The Nelson Aalen cumulative probability estimates in Figure 9 show a low revision incidence rate of bariatric procedures. At one-year post primary procedure, 1.4% (95% CI 1.3% to 1.5%) of patients are estimated to have had their first revision procedure. At two years post primary procedure, 2.7% (95% CI 2.5% to 2.9%) are estimated to have had their first revision procedure.

Bariatric Surgery Registry Sixth Annual Report: 2017/18

DESIGNED AND PRODUCED BY MPS MONASH: 246260 SEPTEMBER 2018. CRICOS PROVIDER: MONASH UNIVERSITY 00008C.

2017/18 report - monash university · excess weight loss (ewl) measure of the percentage of excess...

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