How accurate are home blood pressure monitors used by patients?

ISRCTN ISRCTN12562576
DOI https://doi.org/10.1186/ISRCTN12562576
Secondary identifying numbers 20163
Submission date
17/03/2016
Registration date
17/03/2016
Last edited
26/01/2018
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
The heart is responsible for pumping blood around the body to deliver oxygen-rich blood. In order to do this a certain amount of pressure is needed in the blood vessels, but if this pressure is too high, then it puts a great strain on the arteries and heart. This is called hypertension (high blood pressure), which is very common and often long-term (chronic). Many people with hypertension are unaware of it, as it rarely causes any noticeable symptoms. If left untreated however, it dramatically increases the risk of heart disease, kidney disease and stroke, earning it the nickname of the “silent killer”. It is therefore very important to monitor these people in order to ensure that they do not develop these complications. There is a wide range of blood pressure monitors available for use at home, although it is not known how accurate the measurements are. The aim of this study is to find out how well home blood pressure monitors work at measuring blood pressure.

Who can participate?
Adults with high blood pressure who own a home blood pressure monitor.

What does the study involve?
Participants are sent a letter by their GP practice asking if they would like to have their home blood pressure monitor tested for accuracy. Those who respond are asked to drop off their blood pressure monitor to their practice on a prearranged day. Monitors are tested and returned to participants, complete with testing results, within 2 weeks. The study team tests the patients’ blood pressure monitors using the OMRON PA350 digital BP tester (a specialised piece of equipment designed to measure how accurately blood pressure monitors can measure pressure). Monitors are inflated following a standard process as recommended by each monitor manufacturer and the British Hypertension Society. Monitors that have a 3mmHg or greater difference from the PA350 reading at any blood pressure level are rated as having failed. The study team also assess whether cuffs are working properly.

What are the possible benefits and risks of participating?
Participants will benefit from learning how accurate their home blood pressure monitor is and so it can be replaced if it is inaccurate. There are no direct risks of taking part, although some participants may find it difficult not having their monitor available while it is being tested.

Where is the study run from?
The testing takes place at the University of Birmingham and participants are recruited from GP practices in the Midlands (UK)

When is the study starting and how long is it expected to run for?
February 2016 to December 2016

Who is funding the study?
National Institute for Health Research (UK)

Who is the main contact?
Dr James Hodgkinson
j.a.hodgkinson@bham.ac.uk

Contact information

Dr James Hodgkinson
Scientific

University of Birmingham
Department of Primary Care & General Practice
Primary Care Clinical Sciences Building
Edgbaston
Birmingham
B15 2TT
United Kingdom

Phone +44 1214 148842
Email j.a.hodgkinson@bham.ac.uk

Study information

Study designNon-randomised diagnostic accuracy study
Primary study designInterventional
Secondary study designNon randomised study
Study setting(s)Other
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleAccuracy of patient-owned blood pressure monitors compared to Omron PA350 monitor checker
Study acronymACCU-RATE
Study objectivesPrimary aim:
To determine how accurate are home digital upper arm and wrist blood pressure monitors.

Secondary aims:
1. To find out which digital blood pressure monitors are currently used by patients
2. How well they perform;
3. Is there any evidence of decreasing accuracy over time, or with greater usage, or by validation status, or cost (recommended retail price) of device
Ethics approval(s)15/NW/0828
Health condition(s) or problem(s) studiedTopic: Primary Care; Subtopic: Primary Care; Disease: All Diseases
InterventionEligible patients are sent a letter asking if they are interested in having their monitor tested for accuracy. Those who respond (by telephone or post) will be asked to drop off their monitor to the practice on a prearranged day. Monitors will be tested and returned to participants with results within 2 weeks.

The procedure will be to test patients’ blood pressure (BP) monitors using the OMRON PA350 digital BP tester. Monitors will be inflated following a standard process as recommended by each monitor manufacturer and the British Hypertension Society, with a pass rate of +/- 3mmHg or less from the PA350 reading.
Intervention typeOther
Primary outcome measureBlood pressure monitor accuracy is determined by recording the proportion of devices with <3mmHg error compared to reference device (PA 350) at all BP ranges.
Secondary outcome measures1. Mean, standard deviation, median and interquartile range of mean absolute error (MAE) – i.e. the mean difference between the values reported by the test device and reference device over the pressure ranges tested.
2. Association between mean absolute error and:
1. Number of usages of device
2. Length of time in service of device
3. Validation status of device
4. Recommended retail price of device
Overall study start date11/02/2016
Completion date31/12/2016

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participantsPlanned Sample Size: 385; UK Sample Size 385
Key inclusion criteriaThe inclusion criteria to receive the one page survey are:
Patients on the hypertension register.

The additional inclusion criteria for the monitor testing element:
1. Patients owning blood pressure monitors used at home
2. Participant is willing to take part in the study
Key exclusion criteriaExclusion criteria for the monitor testing element:
1. Unable to provide consent
2. Patients who do not use home blood pressure monitors
3. Housebound patients who are unable to arrange for their monitor to be dropped off at the practice
Date of first enrolment11/02/2016
Date of final enrolment31/10/2016

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

University of Birmingham
Department of Primary Care & General Practice
Primary Care Clinical Sciences Building
Edgbaston
Birmingham
B15 2TT
United Kingdom

Sponsor information

University of Birmingham
University/education

Department of Primary Care & General Practice
Edgbaston
Birmingham
B15 2TT
England
United Kingdom

ROR logo "ROR" https://ror.org/03angcq70

Funders

Funder type

Government

National Institute for Health Research
Government organisation / National government
Alternative name(s)
National Institute for Health Research, NIHR Research, NIHRresearch, NIHR - National Institute for Health Research, NIHR (The National Institute for Health and Care Research), NIHR
Location
United Kingdom

Results and Publications

Intention to publish date31/12/2017
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot expected to be made available
Publication and dissemination planPlanned publication of study findings (at the aggregate level) in a peer reviewed journal, and at an academic conference (most likely SAPC). All participants will receive the full results for their own monitor, and a copy of the overall (aggregate) results if they wish.
IPD sharing planThe reason for the non-availability of participant level data is simply that our unit of analysis is the blood pressure monitor rather than the human owner of the monitor, so we haven’t recorded the characteristics of the owners as they’re not relevant to our study.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Basic results 20/12/2017 26/01/2018 No No
HRA research summary 28/06/2023 No No

Additional files

ISRCTN12562576_BasicResults_20Dec17.docx
Uploaded 26/01/2018

Editorial Notes

26/01/2018: The basic results of this trial have been uploaded as an additional file.
24/03/2016: Verified study information with principal investigator.