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Trial registered on ANZCTR


Registration number
ACTRN12617000656336
Ethics application status
Approved
Date submitted
2/05/2017
Date registered
5/05/2017
Date last updated
31/05/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Validation of Whole Blood Point of Care B-hCG Testing for Pregnancy Using Urine Pregnancy Assay in Women of Reproductive Age Presenting to the Emergency Department
Scientific title
Validation of Whole Blood Point of Care B-hCG Testing for Pregnancy Using Urine Pregnancy Assay in Women of Reproductive Age Presenting to the Emergency Department - A Diagnostic Test Accuracy Study
Secondary ID [1] 291465 0
None
Universal Trial Number (UTN)
U1111-1194-3181
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Pregnancy 302517 0
Condition category
Condition code
Reproductive Health and Childbirth 302063 302063 0 0
Normal pregnancy

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The study aims to validate the use of whole blood for point of care testing to quickly determine a patient's pregnancy status. The current testing options are a urine point of care test, or a serum sample sent to the pathology lab. The point of care test pack inserts state that whole blood cannot be used with them, but in practice they have been used that way and expedited decision-making.

A convenience sample of female patients of reproductive age presenting to the Emergency Department who would typically have their pregnancy status checked, will be recruited to the study. A whole blood B-hCG (point of care), a urine B-hCG (point of care), and a serum sample for quantitative hCG will be tested.

All samples will be collected and tested as soon as practically able after the patient has been triaged into the Emergency Department, in keeping with routine practice. Urine samples will be collected as soon as the patient is able to provide them, and tested as soon as able following that. Blood samples (which will be used for both point of care B-hCG testing and the lab serum test), will be drawn as soon as the phlebotomists or clinicians are able to draw blood from the patient. 3 drops of the blood obtained will be tested using the bedside point of care B-hCG test immediately, and the rest will be sent to the lab for testing, as per current practice. There will be no predetermined order of obtaining the samples.

The point of care test kit that will be used is the Alere TestPack Plus hCG Combo, which has a manufacturer stated sensitivity and specificity of 99%.

The serum sample will be sent to pathology for a quantitative B-hCG result, and will be used as the standard for comparison. A result of <1.2 units/L is a negative pregnancy test. A result of >1.2 units/L is a positive pregnancy test. The results from the urine and whole blood point of care tests will be compared against this, to determine their sensitivity and specificity.
Intervention code [1] 297521 0
Diagnosis / Prognosis
Comparator / control treatment
The patient's serum B-hCG result from the lab is the gold standard result, or the control. The same patient's urine B-hCG result and whole blood B-hCG result from the point of care testing cartridges will be compared against this.
Control group
Active

Outcomes
Primary outcome [1] 301488 0
Sensitivity of whole blood point of care B-hCG testing for detecting pregnancy, with lab serum B-hCG used as control.
Timepoint [1] 301488 0
At point of contact.
Primary outcome [2] 301489 0
Specificity of whole blood point of care B-hCG testing for detecting pregnancy, with lab serum B-hCG used as control.
Timepoint [2] 301489 0
At point of contact.
Secondary outcome [1] 332824 0
Sensitivity of urine point of care B-hCG testing for detecting pregnancy, with lab serum B-hCG used as control.
Timepoint [1] 332824 0
At point of contact.
Secondary outcome [2] 332825 0
Specificity of urine point of care B-hCG testing for detecting pregnancy, with lab serum B-hCG used as control.
Timepoint [2] 332825 0
At point of contact.

Eligibility
Key inclusion criteria
Female
Childbearing age (16-50 years old)
Would have serum B-hCG tested as part of usual care
Minimum age
16 Years
Maximum age
50 Years
Gender
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Younger than 16 years old - not seen at this facility
Patients who do not wish to participate in the study

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)
Allocation is not concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
No randomisation needed for this study,
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Sample size calculation:
Number needed for sensitivity of 99% = Z2 x (Sens (1-Sens)) / ((confidence interval)2 (prevalence))

Z = 1.96 (using alpha of 0.05, intended p-value < 0.05)
Sens = 0.99. The point of care B-hCG testing kit that will be used in this study has manufacturer stated sensitivity and specificity of99%.
Confidence interval = 0.03
Prevalence = 3.85%. The prevalance of pregnancy in the population of female patients of reproductive age presenting to this Emergency Department over the past couple of years has been 6.5 to 7.9%.
? However, this prevalence includes a large proportion of patients who are already known to be pregnant. These patients are unlikely to be included in the study, particularly those in advanced pregnancy, as we would not be checking whether they are pregnant as part of their care in the Emergency Department. The prevalence of early or previously unknown pregnancy here is difficult to determine from the captured presentation data. The prevalence of ectopic pregnancies in females of reproductive age in this department has been 0.5 to 0.6% over the past couple of years. Previous studies done elsewhere have found a prevalence of previously unrecognised pregnancy in females of reproductive age in the Emergency Department of 2.3 to 6.3% (1,2).
We have chosen to use our estimated prevalence of previously unknown or unconfirmed pregnancy as half of the sum of the prevalence of diagnosed pregnancy and ectopic pregnancies (listed as separate diagnoses here) in this department. (((7.2 + 0.5) / 2) = 3.85)

Intended power = 90%

--> required sample size = 1098

References:
1) J Strote, G Chen. Patient self assessment of pregnancy status in the emergency
Department. Emerg Med J 2006;23:554–557.
2) Stengel CL, Seaberg DC, MacLeod BA. Pregnancy in the emergency department: risk factors and prevalence among all women. Ann Emerg Med. 1994 Oct;24(4):697-700.


The sensitivity and specificity of the point of care B-hCG testing cartridges when whole blood is used will be tested, using the lab serum B-hCG as the gold standard comparator.

Lab serum B-hCG +ve Lab serum B-hCG –ve
Whole blood B-hCG +ve True positives False positives
Whole blood B-hCG -ve False negatives True negatives

The sensitivity and specificity of the point of care B-hCG testing cartridges when urine is used will be tested, using the lab serum B-hCG as the gold standard comparator.

Lab serum B-hCG +ve Lab serum B-hCG –ve
Urine B-hCG +ve True positives False positives
Urine B-hCG -ve False negatives True negatives



Recruitment
Recruitment status
Withdrawn
Reason for early stopping/withdrawal
Other reasons/comments
Other reasons
Study was approved by Ethics and Governance, but the Pathology department would not support the study. It would require a significant protocol change to do the study without Pathology support (includes the phlebotomists), which would result in study outcomes not reflecting our actual clinical practice.
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 in Australia
Recruitment state(s)
QLD
Recruitment hospital [1] 7687 0
Mater Adult Hospital - South Brisbane
Recruitment postcode(s) [1] 15605 0
4101 - South Brisbane

Funding & Sponsors
Funding source category [1] 295935 0
Hospital
Name [1] 295935 0
Mater Adult Hospital
Address [1] 295935 0
Raymond Terrace
South Brisbane
QLD 4101
Country [1] 295935 0
Australia
Primary sponsor type
Hospital
Name
Mater Adult Hospital Emergency Department
Address
Raymond Terrace
South Brisbane
QLD 4101
Country
Australia
Secondary sponsor category [1] 294810 0
None
Name [1] 294810 0
Address [1] 294810 0
Country [1] 294810 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 297215 0
Mater HREC
Ethics committee address [1] 297215 0
Mater Health Services Research Ethics
Room 294, Level 2, Aubigny Place
Raymond Terrace
South Brisbane Qld 4101
Ethics committee country [1] 297215 0
Australia
Date submitted for ethics approval [1] 297215 0
10/05/2017
Approval date [1] 297215 0
09/01/2018
Ethics approval number [1] 297215 0
HREC/17/MHS/49

Summary
Brief summary
Anecdotally, whole blood can be used on point of care cartridges for rapid determination of a patient's pregnancy status. Early identification of pregnancy status is important in the case of females of reproductive age with abdominal pain, as the possibility of a pregnancy (including an ectopic pregnancy) can be quickly included or excluded. The manufacturers of the point of care testing cartridges, however, state that these can only be used with urine or serum, both of which there is often a delay in obtaining.
This study aims to validate the use of whole blood for rapid point of care investigation for pregnancy.
The hypothesis is that the whole blood point of care testing will have similar sensitivity and specificity to lab serum testing for detection of pregnancy.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 73362 0
Dr Xiu Lee
Address 73362 0
Mater Adult Emergency Department
Raymond Terrace
South Brisbane
Qld 4101
Country 73362 0
Australia
Phone 73362 0
+61 7 3163 8111
Fax 73362 0
Email 73362 0
xiu.lee@mater.org.au
Contact person for public queries
Name 73363 0
Dr Xiu Lee
Address 73363 0
Mater Adult Emergency Department
Raymond Terrace
South Brisbane
Qld 4101
Country 73363 0
Australia
Phone 73363 0
+61 7 31638111
Fax 73363 0
Email 73363 0
xiu.lee@mater.org.au
Contact person for scientific queries
Name 73364 0
Dr Xiu Lee
Address 73364 0
Mater Adult Emergency Department
Raymond Terrace
South Brisbane
Qld 4101
Country 73364 0
Australia
Phone 73364 0
+61 7 31638111
Fax 73364 0
Email 73364 0
xiu.lee@mater.org.au

No data has been provided for results reporting
Summary results
Not applicable