Condition category
Not Applicable
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Haemoglobin is an iron-containing protein found in red blood cells that carries oxygen around the body. Blood donor services have to measure haemoglobin levels in advance of each blood donation to protect the health of donors (e.g., to prevent anaemia) and to ensure the quality of blood products. NHS Blood and Transplant (NHSBT) measure the haemoglobin levels of donors using a crude but cheap method. A drop of donor’s blood is put into a copper sulphate solution. If the drop sinks sufficiently, then it is judged that the donor’s haemoglobin levels are high enough to donate. If the drop doesn’t sink sufficiently, then a more accurate and costly test is used (“Hemocue”). No other blood service of a major industrialised country now uses this approach. Alternative methods used by other blood services may be more accurate, donor-friendly, and less time consuming. However, their comparative merits have not been investigated thoroughly. Here, we are going to do a survey of donors attending blood donation sessions across England to compare different strategies for haemoglobin testing. Results from this study should help to shape NHSBT (and international) policy concerning haemoglobin screening and to inform a major imminent procurement decision of NHSBT.

Who can participate?
Adults aged at least 18 from blood donation sessions across England.

What does the study involve?
Haemoglobin levels are measured with the current NHSBT method and with: i) a “post-donation” strategy, ii) Hemocue® on capillary blood, iii) a non-invasive strategy, and iv) a “gold standard” haemoglobin measurement. At the end of the study, we compare the accuracy of each strategy compared to the “gold-standard” haemoglobin measurement and NHSBT’s current approach. Furthermore, we look at : (1) feasibility and acceptability of approaches for donors; (2) feasibility and acceptability of approaches for blood services staff; and (3) cost-effectiveness and operational impact for NHSBT.

What are the possible benefits and risks of participating?
There will be no immediate direct benefit or risk to those taking part. NHSBT will continue to follow its routine safety procedures to monitor haemoglobin level before donation. However, there should be benefits to future blood donors and to the country's future blood supply because the results of the study are likely to influence how the NHSBT screen for haemoglobin levels before blood donations.

Where is the study run from?
University of Cambridge in collaboration with NHS Blood and Transplant (NHSBT)

When is the study starting and how long is it expected to run for?
October 2015 to October 2025

Who is funding the study?
1. NHS Blood and Transplant (NHSBT)
2. University of Cambridge

Who is the main contact?
Dr Emanuele Di Angelantonio

Trial website

Contact information



Primary contact

Dr Emanuele Di Angelantonio


Contact details

Worts Causeway
Dept Public Health and Primary Care
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Comparison of NHSBT’s current approach with three alternative strategies to assess haemoglobin levels in whole blood donors (COMPARE study)



Study hypothesis

We aim to identify the optimum strategy to measure haemoglobin levels in potential whole blood donors in advance of each donation. The principal assessment will compare the current NHSBT screening method with three other alternative methods. We hypothesize that the current NHSBT method will involve a higher number of donors inappropriately bled donors than the other newer methods. The null hypothesis is that there are no differences across methods in the numbers of donors who would have been inappropriately bled.

Ethics approval

Cambridge East, 18/12/2015, ref: 15/EE/0335

Study design

Multi-site observational study

Primary study design


Secondary study design

Epidemiological study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Measurement of haemoglobin concentration of potential whole blood donors.


We will compare the following three haemoglobin tests which are used by blood services in major Western industrialised countries against the results of a “gold standard” haematology analyser and against the results of the current NHSBT method:
1. A “post-donation” method: This method involves using haemoglobin levels obtained from a “gold standard” haematology analyser at the most recent blood donation visit to predict the donor’s haemoglobin level at the next visit
2. A capillary point-of-care test: This method involves taking a drop of capillary blood after a finger-prick and measuring haemoglobin levels using a rapid Hemocue test
3. A non-invasive strategy: This method involves either of two hand-held spectrometer devices (ie, MBR Haemospect® versus Orsense NMB200®) that estimate haemoglobin levels by shining a light on the skin of a donor’s finger

Intervention type



Drug names

Primary outcome measure

The primary endpoint will be the numbers of donors in the study who would have been inappropriately bled by each method (ie, donors who had haemoglobin levels <125g/L for women and <135g/L for men, according to European Union regulations). The principal assessment will compare the current NHSBT screening method with each of the three other alternative methods listed above. Specific measures to be calculated include false pass rate, sensitivity and specificity in detecting haemoglobin levels below the recommended cut-offs for whole blood donation.

Secondary outcome measures

We will study the following important and pre-specified secondary endpoints:

1. Differences in the numbers of donors who would have inappropriately bled when comparing the various newer methods to be studied with one another
2. Differences in the numbers of donors who would have been inappropriately bled when comparing the two non-invasive devices to be studied with each other
3. Feasibility and acceptability of different methods, according to the views of and blood services staff
4. Cost-effectiveness of different methods
5. Variability of the performance of different methods by donors’ personal characteristics
6. Medium and long-term health consequences of inappropriately bleeding at donation.
7. Biological mechanisms underlying personal characteristics (such as genetic profile) that may influence recovery of haemoglobin levels and iron metabolism after blood donation

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Age ≥18 years and fulfilling all normal criteria for blood donation with the exception of pre-donation haemoglobin levels measured using the current NHSBT methods
2. Willing to undergo additional haemoglobin measurement
3. Willing to donate an extra blood sample for measurement of haemoglobin using an automated cell counter
4. Willing to come back for a subsequent appointment at standard donation interval (ie 12-wk and 16-wk for men and women respectively)

Participant type

Healthy volunteer

Age group




Target number of participants


Participant exclusion criteria

1. Participants who do not have internet access and/or are not willing to provide an email address for study correspondence (as the study will aim to be almost “paper-less” and will involve remote web-based data collection)
2. Donors already enrolled in the INTERVAL randomised trial will be excluded

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

NHSBT - Blood donation mobile session
United Kingdom

Sponsor information


NHS Blood and Transplant

Sponsor details

500 North Bristol Park
BS34 7QH
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type

Not defined

Funder name

NHS Blood and Transplant

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

University of Cambridge

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high impact peer reviewed journal.

IPD sharing statement:
The datasets generated and/or analysed during the current study are/will be available upon request and approval from the COMPARE Data Access Committee [contact:].

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

11/07/2017: Internal review 05/06/2017: Added the ethics approval date as well as publication and the participant level data sharing statement. 18/05/2017: Intention to publish date changed from 01/06/2017 to 17/03/2018. Overall trial end date was changed from 01/09/2016 to 01/10/2025. Recruitment end date changed from 01/09/2016 to 21/03/2017. Updated website, publication and dissemination plan. 13/11/2015: The recruitment start date has been updated from 01/10/2015 to 01/01/2016.