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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Investigating the feasibility of implementing a pre-operative VLCD weight loss program into the pre-operative model of care for general elective surgery patients
Scientific title
Investigating the feasibility of implementing a pre-operative VLCD weight loss program into the pre-operative model of care for general elective surgery patients
Secondary ID [1] 290134 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obesity 300255 0
Condition category
Condition code
Diet and Nutrition 300120 300120 0 0
Surgery 300121 300121 0 0
Other surgery

Study type
Description of intervention(s) / exposure
The intervention is an 8 week Very Low Calorie Diet weight loss program that utlises Optifast meal replacement shakes to 700-800calories/ day intake. This will be achieved through the daily oral consumption of 3-4 Optifast products (shakes) with an additional 2 cups (non-starch) salad, at least 2 litres of calorie free fluids, and 1 teaspoon of oil.
Processes established to measure fidelity / adherence to treatment protocols will be implemented which may include but not limited to urinary ketones. Urinary ketones will be collected by the clinic nurse.
Intervention code [1] 295889 0
Intervention code [2] 296338 0
Treatment: Other
Comparator / control treatment
As part of standard care, a generic weight loss education pack will be provided to participants randomised to the control group at week 0 by the clinic nurse. The weight loss information pack includes tips on healthy eating and contact details of where to access Dietitian/ weight loss advice in the community. The pack has been previously developed by Dietitians in the Department and is used in standard practice.
Control group

Primary outcome [1] 299601 0
Evaluating the feasibility of implementing a pre-operative VLCD weight program in general elective surgery patients at The Prince Charles Hospital.
Feasibility will be determined by evaluating acceptability, demand, practicality and integration.
Areas of Focus
1. Changes in Health Related Quality of Life scores of participants (Acceptability)
2. Recruitment rate of participants (n=50) in the projected time frame (at least 6 participants/ month) (Demand)
3. Participant attendance rates to clinic appointments (Demand)
4. Changes in weight and body composition from week 0 to week 8 in participants receiving the intervention, compared to the control group will be measured using bioelectrical impedance (Practicality)
5. Participant adherence to VLCD program by participants. Urinary ketones will be used as a fidelity measure.(Practicality)
6. Duration (days) on theatre list, and number of patients with delayed surgeries due to obesity (Practicality).
7. Determine Quality Adjusted Life Years (QALYs) using cost utility analysis (Practicality)
8. Determine perceived fit and sustainability of the program by Key stakeholders. Focus groups with key stakeholders will be undertaken (Integration)
Timepoint [1] 299601 0
Time point, post randomisation 1: 8 weeks
Time point 2, post randomisation: 12 months
Secondary outcome [1] 327661 0
Composite secondary outcome: 'Unfavourable surgical outcomes'
LOS >20% than expected for DRG
Hospital Readmission <30days
Surgical site infection
Delayed wound healing
Hospital Acquired Pressure Injury Stage 1-4
Unplanned return to theatre
Venous thromboembolism (VTE)
Myocardial Infarction
Conversions from laparoscopic to open surgery
Unplanned Intensive Care admission
Intraoperative time
Requirement for rehabilitation

Data to determine outcomes witll be obtained from participants relevant medical records.
Timepoint [1] 327661 0
30 days post surgery.

Key inclusion criteria
Elective general surgical patients at The Prince Charles Hospital
BMI >30kgm2
>18 years old
eGFR >60ml/min/1.73m2
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Pregnant, preparing undergoing IVF
Cirrhosis, liver failure, portal hypertension
Acute cardiovascular disease
Type 1 Diabetes Mellitus
Use lithium
long-term use of corticosteroids (> 2 weeks duration)
People with an intellectual or mental impairment

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
The use of sequentially numbered opaque sealed envelopes will ensure allocation concealment as participants and investigators enrolling participants will not foresee assignment.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The primary research clinician will randomly allocate eligible consented patients using sequentially numbered opaque sealed envelopes that contained allocation into the intervention or the control arm. The sequentially numbered envelopes will be produced using computer software and sealed by an independent statistician prior to the activation of the trial.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Sample size estimation
The increased risk of surgical complications in obese patients varies throughout the literature with reports of complications between 4-54%. It is hypothesised that the intervention will reduce unfavourable surgical outcomes from 15% to 5%. The sample sizes required to detect a significant difference between the two groups (alpha 0.05) with 80% power are n=141 in each arm (total n=282). The command power two proportions p1 p2, test (chi2) were used to estimate sample size, where p1 and p2 refer to the expected proportions of patients that experience an unfavourable outcome in the control and intervention groups respectively.Due to the small sample size (n=50) this pilot study will not have the power to determine significance when evaluating surgical outcomes. A successful feasibility study will provide the opportunity for a larger study; stage 2, which will focus on surgical outcomes as a primary outcome.

Statistical methods
Descriptive statistics will be presented for all variables. Univariable associations between the intervention (VLCD) and the main binary outcome (i.e. adverse outcome) will be analysed using Chi square analyses. Associations between other categorical variables of interest and the outcome will be analysed using Chi square analyses and associations between continuous variables and the outcome will be analysed using Student’s t-tests or non-parametric methods as indicated by the distributions of variables of interest. Logistic regression analyses may be performed as indicated

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 6654 0
The Prince Charles Hospital - Chermside
Recruitment postcode(s) [1] 14279 0
4032 - Chermside

Funding & Sponsors
Funding source category [1] 294509 0
Name [1] 294509 0
The Prince Charles Hospital
Address [1] 294509 0
Rode Rd
Chermside QLD 4032
Country [1] 294509 0
Primary sponsor type
Department of Surgery and Department of Nutrition and Dietetics, The Prince Charles Hospital
Rode Rd
Chermside QLD 4032
Secondary sponsor category [1] 293373 0
Name [1] 293373 0
Address [1] 293373 0
Country [1] 293373 0

Ethics approval
Ethics application status
Ethics committee name [1] 295941 0
The Prince Charles Hospital Human Research Ethics Committee
Ethics committee address [1] 295941 0
The Prince Charles Hospital
Building 14
Rode Road, Chermside
QLD 4032
Ethics committee country [1] 295941 0
Date submitted for ethics approval [1] 295941 0
Approval date [1] 295941 0
Ethics approval number [1] 295941 0
Ethics committee name [2] 295942 0
Human Ethics Unit, The University of Queensland
Ethics committee address [2] 295942 0
St Lucia, Brisbane
Queensland 4072
Ethics committee country [2] 295942 0
Date submitted for ethics approval [2] 295942 0
Approval date [2] 295942 0
Ethics approval number [2] 295942 0

Brief summary
This pilot study will investigate the feasibility of implementing a multidisciplinary pre-operative very low calorie (VLCD) weight loss program in adult obese patients awaiting general elective surgery.
This study will initially enrol a pilot sample of 50 patients who have a Body mass Index (BMI) equal to or over 30kg/m2 who attend the Pre-admission clinic for elective general surgery at The Prince Charles Hospital. Participants will be randomised into a control group or an intervention group. Participants in the intervention group will follow an 8 week very low calorie diet that incorporates Optifast meal replacement shakes. Participants randomised to the control group will receive standard care that includes a generic weight loss information pack provided by the clinic nurse.

Measures to assess health related quality of life, body composition and adherence to the program will be collected. Unfavourable surgical outcomes will be measured until 30 days post elective surgery.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 68990 0
Ms Greta Hollis
Address 68990 0
The Prince Charles Hospital
Rode Road
Chermside QLD 4032
Country 68990 0
Phone 68990 0
+61 7 31394640
Fax 68990 0
Email 68990 0
Contact person for public queries
Name 68991 0
Ms Greta Hollis
Address 68991 0
The Prince Charles Hospital
Rode Road
Chermside QLD 4032
Country 68991 0
Phone 68991 0
+61 7 31394640
Fax 68991 0
Email 68991 0
Contact person for scientific queries
Name 68992 0
Ms Greta Hollis
Address 68992 0
The Prince Charles Hospital
Rode Road
Chermside QLD 4032
Country 68992 0
Phone 68992 0
+61 7 31394640
Fax 68992 0
Email 68992 0

No information has been provided regarding IPD availability
Summary results
No Results