ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12615001264572

Ethics application status

Approved

Date submitted

13/11/2015

Date registered

19/11/2015

Date last updated

1/09/2020

Date data sharing statement initially provided

1/09/2020

Type of registration

Prospectively registered

Titles & IDs

Public title

Use of the six minute walk test to predict recovery and complications in morbidly obese patients undergoing elective surgery

Scientific title

In severely obese patients presenting for elective surgery, can the six minute walk test predict recovery and medical complications?

Secondary ID [1]

none

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Severe obesity

Post-operative functional recovery and medical complications

Condition category

Condition code

Diet and Nutrition

Obesity

Surgery

Other surgery

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Performance of the six minute walk test. This measures the distance that a patient can walk in 6 minutes and is follows steps delineated by a standard operating procedure. This will occur in the pre-operative assessment clinic and be supervised by a research assistant who will be trained in supervision of the test..
Performance of spirometry, measurement of waist and hip circumferences, and of serum NT pro-BNP will also occur in the pre-operative assessment clinic. These are study measures and are not measured routinely.
Patients visit the pre-operative assessment clinics between one day and 6 weeks prior to their scheduled date of surgery.

Intervention code [1]

Early detection / Screening

Comparator / control treatment

No control group

Control group

Uncontrolled

Outcomes

Primary outcome [1]

Functional recovery as measured by the WHODAS 2.0 and QOR-15 tools.

Timepoint [1]

The recovery measurement surveys will occur at the following times after surgery: QOR-15 at 3 and 30 days, WHODAS 2.0 at 30 days and at 6 months.

Secondary outcome [1]

Medical complications will be measured using a standard checklist with standard measures and definitions. Data will be gathered by a research assistant searching the medical record, and confirming with the patient at the 30 day post-operative interview.

Timepoint [1]

Within first 30 days post-operatively.

Eligibility

Key inclusion criteria

Consent
Age => 18 years
BMI => 35 at pre-admission clinic
Booked for elective non-cardiac surgery at Wollongong hospital

Minimum age

18 Years

Maximum age

No limit

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

Inadequate time to complete the 6MWT pre-operatively
Presence of medical contra-indications to the 6MWT test as per American Thoracic Society guidelines
Pregnancy

Study design

Purpose of the study

Diagnosis

Allocation to intervention

Non-randomised trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

N/A

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

N/A

Masking / blinding

Open (masking not used)

Who is / are masked / blinded?

Intervention assignment

Single group

Other design features

Follow-up to 6 months post-operatively
The aim of this trial is to test the predictive value of a pre-operative screening tool for risk assessment and stratification in a specific patient population group.

Phase

Not Applicable

Type of endpoint/s

Safety/efficacy

Statistical methods / analysis

Correlation statistics: mainly receiver operating characteristic (ROC) method, with linear regression and use of t-tests where appropriate. Sample size was determined using published tables. We estimated the correlation co-efficient to be 0.5 as the outcomes are somewhat nut not completely correlated. We chose confidence intervals to be no wider than -/+ 0.1. A sample size of 219 met these requirements. We added c 10% extra to this to account for losses between study recruitment and completion to give an overall sample size of 250. Based on an audit of numbers of severely obese patients presenting to the Wollongong pre-operative clinic, we estimated that up to 18 months should be sufficient to recruit this sample size.

Recruitment

Recruitment status

Completed

Date of first participant enrolment

Anticipated

8/02/2016

Actual

8/02/2017

Date of last participant enrolment

Anticipated

1/08/2017

Actual

1/12/2017

Date of last data collection

Anticipated

Actual

1/06/2018

Sample size

Target

250

Accrual to date

Final

285

Recruitment in Australia

Recruitment state(s)

NSW

Recruitment hospital [1]

Wollongong Hospital - Wollongong

Recruitment postcode(s) [1]

2500 - Wollongong

Funding & Sponsors

Funding source category [1]

Other

Name [1]

ANZCA (Australia and New Zealand College of Anaesthetists) Research Committee

Address [1]

630 St Kilda Rd
Melbourne
Vic 3004

Country [1]

Australia

Funding source category [2]

University

Name [2]

Illawarra Health and Medical Research Institute: University of Wollongong

Address [2]

University of Wollongong
Northfields Ave, North Wollongong
NSW 2500

Country [2]

Australia

Primary sponsor type

Individual

Name

Natalie Smith

Address

c/- Department of Anaesthesia
Wollongong Hospital
Crown St, Wollongong
NSW 2500

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

UOW and ISLHD Health and Medical Research Ethics Committee

Ethics committee address [1]

Ethics Unit, Research Services Office
University of Wollongong
Northfields Ave, Wollongong
NSW 2522

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

16/09/2015

Approval date [1]

15/12/2015

Ethics approval number [1]

Ethics number HE15/379

Summary

Brief summary

Wollongong Hospital is a large regional hospital that performs approximately 13 000 episodes of operative care per year. The range of surgery performed covers all areas apart from cardio-thoracic, including neurosurgery, vascular, orthopaedics, urology, ENT general, colo-rectal, endoscopy, imaging, obstetrics and gynaecology, general paediatrics, and plastic surgery. The anaesthesia department at Wollongong Hospital has an audit and research focus particularly in the fields of education, obesity, and geriatric care.

Australian Bureau of Statistics data report that 62.8% of adult Australians were overweight or obese in 2011-12.  Of this number, approximately 12% had a body mass index (BMI) greater than or equal to 35, which, in the presence of comorbidities, has been defined as morbid obesity. Local data show that at least 13% of patients undergoing elective surgery at Wollongong Hospital each year are morbidly obese.  Most of the literature suggests that morbidly obese patients have higher rates of clinical complications in the post-operative period than the non-obese although this finding has not been universally reported. Assessment of risk in obese patients cannot accurately be based on the presence of obesity alone.

Measurement of functional capacity pre-operatively is considered essential for useful risk stratification and prediction of post-operative outcomes. Cardiopulmonary exercise testing (CPET) is the gold standard for assessing cardio-respiratory fitness. However, CPET is expensive, resource-intensive, and requires a dedicated specialist laboratory and trained technicians. In contrast, the six minute walk test (6MWT) is a simple and cheap test for evaluation of cardio-respiratory function that has compared well to CPEX in previous studies. It may be ideal for assessing functional capacity in morbidly obese patients as it can be performed by existing staff in a pre-operative assessment area and has been shown to be safe for morbidly obese patients in multiple papers.  There are currently no published data on the use of the 6MWT as a screening tool to predict high risk in obese patients undergoing surgery.

The aim of this study is to assess the ability of the 6MWT to predict postoperative functional recovery and medical complications in morbidly obese patients in Wollongong Hospital who attend a pre-admission assessment clinic (PAC). Identification of this subset of patients would allow peri-operative teams to target further investigations, optimise surgical planning, and stratify the intensity of intra-operative and post-operative care. With these strategies, it may be possible to decrease morbidity and mortality and the associated healthcare costs to the community.

Trial website

nil

Trial related presentations / publications

nil

Public notes

Contacts

Principal investigator

Name

A/Prof Natalie Smith

Address

c/- Department of Anaesthesia
Wollongong Hospital
Crown St, Wollongong, NSW 2500

Country

Australia

Phone

+61 2 4255 1560

Fax

[email protected]

Contact person for public queries

Name

Natalie Smith

Address

c/- Department of Anaesthesia
Wollongong Hospital
Crown St, Wollongong, NSW 2500

Country

Australia

Phone

+61 2 4255 1560

Fax

[email protected]

Contact person for scientific queries

Name

Natalie Smith

Address

c/- Department of Anaesthesia
Wollongong Hospital
Crown St, Wollongong, NSW 2500

Country

Australia

Phone

+61 2 4255 1560

Fax

[email protected]

Data sharing statement

Will individual participant data (IPD) for this trial be available (including data dictionaries)?

Yes

What data in particular will be shared?

De-idientified individual participant data after publication

When will data be available (start and end dates)?

Start date: After publication
End date: no end date determined

Available to whom?

Researchers who provide a sound proposal at the discretion of the chief investigator

Available for what types of analyses?

To achieve aims in a proposal, for meta-analysis

How or where can data be obtained?

By contacting the chief investigator by email: [email protected]

What supporting documents are/will be available?

Doc. No.	Type	Email	Other Details
9014	Study protocol		The protocol will be available as part of the main... [More Details]
9015	Statistical analysis plan	[email protected]
9016	Informed consent form	[email protected]
9017	Clinical study report	[email protected]
9018	Ethical approval	[email protected]

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

Source	Title	Year of Publication	DOI
Embase	The clinical, functional and disability characteristics of patients with severe obesity presenting for non-bariatric surgery.	2019	https://dx.doi.org/10.1177/0310057X19887976
Embase	Predicting recovery and disability after surgery in patients with severe obesity: The role of the six-minute walk test.	2022	https://dx.doi.org/10.1177/0310057X20981969

N.B. These documents automatically identified may not have been verified by the study sponsor.

Trial Review

Documents added manually

Documents added automatically