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Trial registered on ANZCTR


Registration number
ACTRN12614001089628
Ethics application status
Approved
Date submitted
30/09/2014
Date registered
13/10/2014
Date last updated
16/06/2017
Type of registration
Prospectively registered

Titles & IDs
Public title
Comparison of blood collection tubes for blood glucose testing in the diagnosis of gestational diabetes.
Scientific title
For pregnant women, does blood collection into a citrate test tube, when compared to the standard collection procedure of using a fluoride test tube, produce more accurate venous plasma glucose results.
Secondary ID [1] 285423 0
Nil known
Universal Trial Number (UTN)
U1111-1162-3227
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
gestational diabetes 293177 0
Condition category
Condition code
Reproductive Health and Childbirth 293453 293453 0 0
Fetal medicine and complications of pregnancy
Public Health 293454 293454 0 0
Health service research
Metabolic and Endocrine 293487 293487 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Interventional study comparing 'new' citrate tubes with conventional fluoride tubes for measuring venous plasma glucose levels during the oral glucose tolerance test in pregnancy. Pregnant women will have blood drawn into three test tubes at each time-point (0-hour, 1-hour, and 2-hour) of their routine oral glucose tolerance test taken between 24-28 weeks' gestation. The usual fluoride tube, the 'new' citrate tube, and a gel tube for the reference glucose.
Intervention code [1] 290342 0
Diagnosis / Prognosis
Intervention code [2] 290426 0
Early detection / Screening
Comparator / control treatment
Pregnant women will have blood drawn into three test tubes at each time-point of their routine oral glucose tolerance test. The three tubes will include the usual fluoride tube, the 'new' citrate tube, and a gel tube for the reference glucose. Each woman will be her own control.
Control group
Active

Outcomes
Primary outcome [1] 293272 0
The difference in venous plasma glucose levels measured in mmol/L between the three types of test tube at each time-point (0-hour, 1-hour, and 2-hours) of the oral glucose tolerance test.
Timepoint [1] 293272 0
At the time of enrolment between 24-28 weeks' gestation, at each time-point (0-hour, 1-hour, and 2-hours) of the oral glucose tolerance test.
Secondary outcome [1] 310699 0
% difference in venous plasma glucose levels measured in the three types of test tube at each time point (0-hour, 1-hour, and 2-hours) of the oral glucose tolerance test.
Timepoint [1] 310699 0
At the time of enrolment between 24-28 weeks' gestation, at each time-point (0-hour, 1-hour, and 2-hours) of the oral glucose tolerance test.

Eligibility
Key inclusion criteria
Pregnant women attending for a routine oral glucose tolerance test to screen for gestational diabetes.
Minimum age
No limit
Maximum age
No limit
Gender
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
nil

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)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 6384 0
New Zealand
State/province [1] 6384 0

Funding & Sponsors
Funding source category [1] 290027 0
University
Name [1] 290027 0
University of Otago Summer Studentship
Address [1] 290027 0
University of Otago Christchurch School of medicine, Christchurch Hospital, Private Bag 4710, Christchurch 8140, Canterbury
Country [1] 290027 0
New Zealand
Primary sponsor type
Individual
Name
Ruth Hughes
Address
Department of Obstetrics and Gynaecology,
Christchurch Women's Hospital
Private Bag 4711
Christchurch 8140
Country
New Zealand
Secondary sponsor category [1] 288719 0
Individual
Name [1] 288719 0
Dr Helen Lunt
Address [1] 288719 0
Department of Medicine,
Christchurch Hospital
Private Bag 4710
Christchurch 8140
Country [1] 288719 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 291735 0
New Zealand Southern health and disability ethics committee
Ethics committee address [1] 291735 0
Ministry of Health
Ethics Department
Freyberg Building
Reception – Ground Floor
20 Aitken Street
Wellington
Ethics committee country [1] 291735 0
New Zealand
Date submitted for ethics approval [1] 291735 0
02/10/2014
Approval date [1] 291735 0
16/10/2014
Ethics approval number [1] 291735 0
14/NTA/167

Summary
Brief summary
This study will see if ‘new’ blood tubes (citrate tubes) are better than the ‘usual’ tubes (fluoride tubes) to test glucose levels. All pregnant women are offered a test for gestational diabetes (GDM) at 24-28 weeks. This is usually with a glucose challenge test (GCT) and / or an oral glucose tolerance test (OGTT). At present, we collect blood samples for these tests into fluoride tubes.

We know that glucose levels may fall in the fluoride tubes in the first hour after the blood is taken. This is important, as there is usually a slight delay between blood collection and laboratory testing of glucose levels. This can result in the measured glucose level being lower than it really is in the body. We might then miss some women with GDM who have a falsely ‘normal’ result. In non-pregnant people, the ‘new’ citrate tubes give results that are more accurate. No one has studied the ‘new’ tubes in pregnancy. We will compare the ‘new’ citrate and ‘usual’ fluoride tubes with a third way of testing glucose that measures the glucose level straight after the blood sample is taken. This third way of testing glucose is the best, but it is not in everyday use as it takes a lot of time to do properly.

We think that the new citrate tubes will be better at detecting GDM than the current system. Missed and untreated cases of GDM can harm the baby. If we show that the ‘new’ citrate tubes are better, then changing to these tubes could mean that we miss fewer women with GDM in the future.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 51798 0
Dr Helen Lunt
Address 51798 0
Department of medicine,
Christchurch Hospital,
Private bag 4710,
Christchurch 8140
Country 51798 0
New Zealand
Phone 51798 0
+64 3 3640640
Fax 51798 0
Email 51798 0
helen.lunt@cdhb.health.nz
Contact person for public queries
Name 51799 0
Dr Helen Lunt
Address 51799 0
Department of medicine,
Christchurch Hospital,
Private bag 4710,
Christchurch 8140
Country 51799 0
New Zealand
Phone 51799 0
+64 3 3640640
Fax 51799 0
Email 51799 0
helen.lunt@cdhb.health.nz
Contact person for scientific queries
Name 51800 0
Dr Helen Lunt
Address 51800 0
Department of medicine,
Christchurch Hospital,
Private bag 4710,
Christchurch 8140
Country 51800 0
New Zealand
Phone 51800 0
+64 3 3640640
Fax 51800 0
Email 51800 0
helen.lunt@cdhb.health.nz

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary