HypertensionNCT03454178
Accuracy of AOBP in a Chinese Population
An observational study of Hypertension, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
Background: Traditional office blood pressure (BP) measurement is often inaccurate and is inferior to out-of-office measurements, such as ambulatory blood pressure monitoring (ABPM), in predicting cardiovascular outcomes. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Hypertension
- What is being tested?
- WatchBP Office (BP measurement machine)
- How many people
- 149 participants
- Where
- 1 siteHong Kong
- Study dates
- 30 Jun 2018to 29 Dec 2019
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Hypertensive patients in primary care
Who may be able to join
- diagnosis of essential hypertension
Who cannot join
- (i) severe hypertension as defined by clinical systolic BP ≥180 mmHg and/or diastolic BP ≥110 mmHg (because they may need emergency treatment and it is unethical to delay such treatment due to the proposed project), (ii) inability to provide consent, (iii) pregnancy, (iv) night-time occupations (we need to compare AOBP and clinic BP readings to daytime ABPM average when the patient should be awake), (v) are occupational drivers (because potential dangers in driving could occur when patients are asked to remain still), (vi) receiving anti-coagulants (to prevent bruises when using ABPM), (vii) with known atrial fibrillation (as ABPMs and AOBP use have not been validated in this group)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Sensitivity, Specificity, and Positive and Negative Predictive Values of Automatic Office Blood Pressure Measurement and Traditional Office Blood Pressure Measurement in a Chinese Population
Background: Traditional office blood pressure (BP) measurement is often inaccurate and is inferior to out-of-office measurements, such as ambulatory blood pressure monitoring (ABPM), in predicting cardiovascular outcomes. A relatively new BP measurement method, called Automatic Office Blood Pressure measurement (AOBP), may provide similar BP readings to ABPM (latest clinical gold standard for BP measurements) and can easily be conducted in clinics. AOBP machines measure BP repeatedly 3-5 times with 1-min intervals and automatically provide the mean BP value. While AOBP was used in landmark trials (e.g. SPRINT trial) and was shown to eliminate white-coat effect, AOBP is rarely used in Hong Kong partly because there is no data concerning the accuracy of AOBP in Chinese. Almost all previous AOBP research used BpTRU (AOBP model), but BpTRU manufacturer was shut down permanently.
Aim: To assess if WatchBP Office (another AOBP model) has superior diagnostic accuracy than traditional office BP measurements, when compared to ABPM readings.
Read more
Method: 150 Chinese adult patients with a diagnosis of essential hypertension will be recruited consecutively from a Government-funded primary care clinic. All patients will have their BP measured by a 48-hour ABPM, a WatchBP office, and two traditional office blood pressure measurements.
ABPM will be considered the gold standard; sensitivity, specificity, positive and negative predictive values of AOBP and traditional BP to diagnose elevated BP level, masked hypertension and white-coat hypertension will be calculated and compared
Implication: if WatchBP provides closer BP readings to ABPM, this can lead to its implementation in routine clinical practice
- Conditions
- Hypertension
- Being tested
- WatchBP Office (BP measurement machine)
- Keywords
- AOBP, ABPM
- Medical subject headings
- Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
WatchBP Office (BP measurement machine)Diagnostic test
BP measurement: The nurse or assistant will leave the room after confirmed validity and the WatchBP will automatically measure BP for the participant at 1-minute intervals for 3 more readings; previous research showed that accurate BP readings could be obtained using 1-minute intervals. This is also the measuring method suggested by the manufacturer. The machine will automatically calculate the mean BP using the 3 readings. The mean BP value will be used for analysis. The diagnostic cutoff for diagnosing HT will be ≥135/85 for AOBP
| Study group | Role | What they receive |
|---|---|---|
| Hypertensive patients | 150 Chinese patients with a diagnosis of essential hypertension from a primary care clinic Receives: Diagnostic Test: WatchBP Office (BP measurement machine) |
What is being measured
The primary outcome is the main question the study is designed to answer.
compare BP readings from AOBPs, ABPM, and traditional office BP
mean difference of systolic BP (SBP) and diastolic BP (DBP) between AOBP machines (WatchBP Office, BpTRU)/office BP and daytime ABPM will be compared by the two-tailed t-test; A Bland-Altman type plot will be shown for both comparisons. Pearson correlations will be used to compare mean readings of office BP, AOBP and daytime ABPM.
Measured: 1 year
Secondary outcomes (1)
sensitivity/specificity, positive and negative predictive value of AOBP vs traditional BP measurement
sensitivity/specificity, positive and negative predictive value of diagnosing elevated BP, masked hypertension, and white-coat hypertension of AOBP and office BP will be compared using ABPM as the gold standard
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Mar 2018
- Study start30 Jun 2018
- Primary completion29 Dec 2019
- Study completion29 Dec 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypertensionStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 149 participants (actual)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Lee Kam Pui, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03454178
- Sponsor's protocol ID
- CUHK-188
- Status last verified
- Sep 2020
- First submitted
- 27 Feb 2018
- Last updated
- 15 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Will be willing to share on request
Study at a glance
From the registry record, last updated by the sponsor on 15 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Sensitivity, Specificity, and Positive and Negative Predictive Values of Automatic Office Blood Pressure Measurement and Traditional Office Blood Pressure Measurement in a Chinese Population
- ClinicalTrials.gov ID
- NCT03454178
- Acronym / sponsor ID
- CUHK-188
- Conditions
- Hypertension
- Keywords
- AOBP, ABPM
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 149 participants (actual)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 30 Jun 2018 (actual)
- Primary completion
- 29 Dec 2019 (actual)
- Study completion
- 29 Dec 2019 (actual)
- First posted
- 5 Mar 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background: Traditional office blood pressure (BP) measurement is often inaccurate and is inferior to out-of-office measurements, such as ambulatory blood pressure monitoring (ABPM), in predicting cardiovascular outcomes. A relatively new BP measurement method, called Automatic Office Blood Pressure measurement (AOBP), may provide similar BP readings to ABPM (latest clinical gold standard for BP measurements) and can easily be conducted in clinics. AOBP machines measure BP repeatedly 3-5 times with 1-min intervals and automatically provide the mean BP value. While AOBP was used in landmark trials (e.g. SPRINT trial) and was shown to eliminate white-coat effect, AOBP is rarely used in Hong Kong partly because there is no data concerning the accuracy of AOBP in Chinese. Almost all previous AOBP research used BpTRU (AOBP model), but BpTRU manufacturer was shut down permanently.
Aim: To assess if WatchBP Office (another AOBP model) has superior diagnostic accuracy than traditional office BP measurements, when compared to ABPM readings.
Method: 150 Chinese adult patients with a diagnosis of essential hypertension will be recruited consecutively from a Government-funded primary care clinic. All patients will have their BP measured by a 48-hour ABPM, a WatchBP office, and two traditional office blood pressure measurements.
ABPM will be considered the gold standard; sensitivity, specificity, positive and negative predictive values of AOBP and traditional BP to diagnose elevated BP level, masked hypertension and white-coat hypertension will be calculated and compared
Implication: if WatchBP provides closer BP readings to ABPM, this can lead to its implementation in routine clinical practice
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Hypertensive patients | – | Diagnostic Test: WatchBP Office (BP measurement machine)150 Chinese patients with a diagnosis of essential hypertension from a primary care clinic |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Hypertensive patients in primary care
Key inclusion criteria (1 listed)
- diagnosis of essential hypertension
Key exclusion criteria (1 listed)
- (i) severe hypertension as defined by clinical systolic BP ≥180 mmHg and/or diastolic BP ≥110 mmHg (because they may need emergency treatment and it is unethical to delay such treatment due to the proposed project), (ii) inability to provide consent, (iii) pregnancy, (iv) night-time occupations (we need to compare AOBP and clinic BP readings to daytime ABPM average when the patient should be awake), (v) are occupational drivers (because potential dangers in driving could occur when patients are asked to remain still), (vi) receiving anti-coagulants (to prevent bruises when using ABPM), (vii) with known atrial fibrillation (as ABPMs and AOBP use have not been validated in this group)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| WatchBP Office (BP measurement machine)BP measurement: The nurse or assistant will leave the room after confirmed validity and the WatchBP will automatically measure BP for the participant at 1-minute intervals for 3 more readings; previous research showed that accurate BP readings could be obtained using 1-minute intervals. This is also the measuring method suggested by the manufacturer. The machine will automatically calculate the mean BP using the 3 readings. The mean BP value will be used for analysis. The diagnostic cutoff for diagnosing HT will be ≥135/85 for AOBP | Diagnostic test | Hypertensive patients |
Primary outcome
compare BP readings from AOBPs, ABPM, and traditional office BP
Time frame: 1 year
mean difference of systolic BP (SBP) and diastolic BP (DBP) between AOBP machines (WatchBP Office, BpTRU)/office BP and daytime ABPM will be compared by the two-tailed t-test; A Bland-Altman type plot will be shown for both comparisons. Pearson correlations will be used to compare mean readings of office BP, AOBP and daytime ABPM.
1 secondary outcome
sensitivity/specificity, positive and negative predictive value of AOBP vs traditional BP measurement
Time frame: 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Dec 2025.
- Individual participant dataSharing planned: Undecided. Will be willing to share on request
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hypertension, run by Chinese University of Hong Kong at 1 site in Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 15 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
compare BP readings from AOBPs, ABPM, and traditional office BP (time frame: 1 year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Dec 2025.