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Trial registered on ANZCTR


Registration number
ACTRN12613001262796
Ethics application status
Approved
Date submitted
13/11/2013
Date registered
18/11/2013
Date last updated
18/11/2013
Type of registration
Retrospectively registered

Titles & IDs
Public title
Comparisons of mercury-free and automated sphygmomanometers with mercury sphygmomanometry in hypertensive and normotensive pregnant women: parallel, prospective, observational study
Scientific title
Comparison of the accuracy of mercury-free and automated sphygmomanometers with mercury sphygmomanometry in hypertensive and normotensive pregnant women
Secondary ID [1] 283558 0
Nil known
Universal Trial Number (UTN)
U1111-1150-1477
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Blood pressure in pregnancy 290464 0
Condition category
Condition code
Reproductive Health and Childbirth 290856 290856 0 0
Fetal medicine and complications of pregnancy

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Nil
Target follow-up type
Description of intervention(s) / exposure
Blood pressure was measured in hypertensive and normotensive pregnant women comparing an automated blood pressure measuring device and a mercury-free sphygmomanometer with a mercury sphygmomanometer as the gold standard. Both of the test devices use a standard blood pressure cuff, but have different ways of determining the blood pressure. The automated device inflates and measures blood pressure electronically, while the non-mercury device uses a manual bulb to inflate and deflate the cuff, similar to mercury sphygmomanometry.
Pregnant women were allocated on a non-random basis to either having the automated device vs mercury or the mercury-free device vs mercury. Each women then had nine blood pressures taken, alternating between mercury and the test device over a 20 minute period.
Intervention code [1] 288255 0
Not applicable
Comparator / control treatment
Mercury sphygmomanometry is the traditional means and gold standard for determining blood pressure. A cuff of the appropriate size is wrapped around the patient's right upper arm and inflated with a connected bulb. The fall in pressure in the cuff is watched on a mercury column and the appearance of the patient's pulse listening with a stethoscope at the elbow is the systolic blood pressure and the disappearance of the pulse is the diastolic blood pressure. Each measurement takes about 10-15 seconds.
Control group
Active

Outcomes
Primary outcome [1] 290855 0
Main outcome measures were the percentages of readings of test devices that were within 5, 10, and 15 mm Hg difference from the readings with mercury sphygmomanometry
Timepoint [1] 290855 0
At time of blood pressure measurement
Secondary outcome [1] 305451 0
Nil
Timepoint [1] 305451 0
Nil

Eligibility
Key inclusion criteria
Hypertensive and normotensive pregnant women in their third trimester
Minimum age
20 Years
Maximum age
No limit
Sex
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
None

Study design
Purpose
Screening
Duration
Cross-sectional
Selection
Convenience sample
Timing
Prospective
Statistical methods / analysis
Sample size of 85 women in each of four groups - non-mercury vs mercury and automated vs mercury - following British Hypertension Society protocol. Differences in readings between mercury and test devices categorised into the percentages of BP differences within 5, 10, and 15 mmHg. For the device to receive an A classification, at least 60% of the differences must be in the less than or equal to 5 mmHg difference group, 85% in the less than or equal to10 mmHg group, and 95% in the less than or equal to15 mmHg category.
Data entered into a Microsoft Excel spreadsheet and the IBM SPSS statistics (Version 20) statistical program used for analysis. Differences between the means of continuous data assessed using the t-test and categorical data tested using chi-squared tests. A probability of <0.05 considered statistically significant. Bland-Altman plots used to determine the agreement between the readings using mercury and the test devices.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
17/02/2010
Date of last participant enrolment
Anticipated
Actual
21/03/2012
Date of last data collection
Anticipated
Actual
Sample size
Target
340
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment hospital [1] 1676 0
St George Hospital - Kogarah
Recruitment postcode(s) [1] 7552 0
2217 - Kogarah

Funding & Sponsors
Funding source category [1] 288243 0
Hospital
Name [1] 288243 0
St George Hospital
Country [1] 288243 0
Australia
Primary sponsor type
Individual
Name
Prof Mark Brown
Address
Department of Renal Medicine
St George Hospital
Gray St
Kogarah
NSW 2217
Country
Australia
Secondary sponsor category [1] 286960 0
None
Name [1] 286960 0
Address [1] 286960 0
Country [1] 286960 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 290167 0
South Eastern Sydney and Illawarra Area Health Service (SESIAHS) HREC - Central Network
Ethics committee address [1] 290167 0
St George Hospital
Gray St
Kogarah
NSW 2217
Ethics committee country [1] 290167 0
Australia
Date submitted for ethics approval [1] 290167 0
Approval date [1] 290167 0
16/12/2009
Ethics approval number [1] 290167 0
HREC/09/STG/165

Summary
Brief summary
Our aim was to find a suitable replacement for mercury sphygmomanometry to measure blood pressure in pregnancy. A mercury-free sphygmomanometer and an automated oscillometric device were compared with mercury sphygmomanometry in 170 hypertensive and 170 normotensive pregnant women. The mercury-free sphygmomanometer appears to be the more accurate and an acceptable replacement for mercury in pregnancy.
Trial website
Trial related presentations / publications
The UM-101 mercury-free sphygmomanometer: a replacement for mercury sphygmomanometry at last? Davis GK, Roberts LM, Mangos G, Brown MA. Society of Obstetric Medicine of Australia and New Zealand. Annual Scientific Meeting. 2012 Sydney
Public notes

Contacts
Principal investigator
Name 44178 0
Prof Mark Brown
Address 44178 0
Dept of Nephrology
St George Hospital
Gray St
Kogarah
NSW 2217
Country 44178 0
Australia
Phone 44178 0
61 2 9113 1111
Fax 44178 0
Email 44178 0
[email protected]
Contact person for public queries
Name 44179 0
Lynne Roberts
Address 44179 0
Dept of Women's Health
St George Hospital
Gray St
Kogarah
NSW 2217
Country 44179 0
Australia
Phone 44179 0
61 2 9113 23117
Fax 44179 0
Email 44179 0
[email protected]
Contact person for scientific queries
Name 44180 0
Gregory Davis
Address 44180 0
Dept of Women's Health
St George Hospital
Gray St
Kogarah
NSW 2217
Country 44180 0
Australia
Phone 44180 0
61 2 9113 2315
Fax 44180 0
Email 44180 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.