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Randomized Controlled Trial
. 2021 Apr;31(2):94-103.
doi: 10.1111/tme.12750. Epub 2020 Dec 20.

Comparison of four methods to measure haemoglobin concentrations in whole blood donors (COMPARE): A diagnostic accuracy study

Steven Bell  1 , Michael Sweeting  1   2 , Anna Ramond  1 , Ryan Chung  1 , Stephen Kaptoge  1 , Matthew Walker  1 , Thomas Bolton  1 , Jennifer Sambrook  3   4 , Carmel Moore  1   5 , Amy McMahon  1 , Sarah Fahle  1 , Donna Cullen  3 , Susan Mehenny  3 , Angela M Wood  1 , Jane Armitage  6 , Willem H Ouwehand  1   3 , Gail Miflin  3 , David J Roberts  3   7 , John Danesh  1 , Emanuele Di Angelantonio  1   3 ; COMPARE Study Group
Affiliations
Randomized Controlled Trial

Comparison of four methods to measure haemoglobin concentrations in whole blood donors (COMPARE): A diagnostic accuracy study

Steven Bell et al. Transfus Med. 2021 Apr.

Abstract

Objective: To compare four haemoglobin measurement methods in whole blood donors.

Background: To safeguard donors, blood services measure haemoglobin concentration in advance of each donation. NHS Blood and Transplant's (NHSBT) customary method have been capillary gravimetry (copper sulphate), followed by venous spectrophotometry (HemoCue) for donors failing gravimetry. However, NHSBT's customary method results in 10% of donors being inappropriately bled (ie, with haemoglobin values below the regulatory threshold).

Methods: We compared the following four methods in 21 840 blood donors (aged ≥18 years) recruited from 10 NHSBT centres in England, with the Sysmex XN-2000 haematology analyser, the reference standard: (1) NHSBT's customary method; (2) "post donation" approach, that is, estimating current haemoglobin concentration from that measured by a haematology analyser at a donor's most recent prior donation; (3) "portable haemoglobinometry" (using capillary HemoCue); (4) non-invasive spectrometry (using MBR Haemospect or Orsense NMB200). We assessed sensitivity; specificity; proportion who would have been inappropriately bled, or rejected from donation ("deferred") incorrectly; and test preference.

Results: Compared with the reference standard, the methods ranged in test sensitivity from 17.0% (MBR Haemospect) to 79.0% (portable haemoglobinometry) in men, and from 19.0% (MBR Haemospect) to 82.8% (portable haemoglobinometry) in women. For specificity, the methods ranged from 87.2% (MBR Haemospect) to 99.9% (NHSBT's customary method) in men, and from 74.1% (Orsense NMB200) to 99.8% (NHSBT's customary method) in women. The proportion of donors who would have been inappropriately bled ranged from 2.2% in men for portable haemoglobinometry to 18.9% in women for MBR Haemospect. The proportion of donors who would have been deferred incorrectly with haemoglobin concentration above the minimum threshold ranged from 0.1% in men for NHSBT's customary method to 20.3% in women for OrSense. Most donors preferred non-invasive spectrometry.

Conclusion: In the largest study reporting head-to-head comparisons of four methods to measure haemoglobin prior to blood donation, our results support replacement of NHSBT's customary method with portable haemoglobinometry.

Keywords: HemoCue; gravimetry; haemoglobin screening; inappropriate bleeding; inappropriate deferral; non-invasive haemoglobin measurement; whole blood donor.

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Conflict of interest statement

John Danesh reports grants, personal fees and non‐financial support from Merck Sharp & Dohme (MSD), grants, personal fees and non‐financial support from Novartis, grants from Pfizer and grants from AstraZeneca outside the submitted work.

John Danesh serves on the International Cardiovascular and Metabolic Advisory Board for Novartis (since 2010); the Steering Committee of UK Biobank (since 2011); the MRC International Advisory Group (ING) member, London (since 2013); the MRC High Throughput Science Omics Panel Member, London (since 2013); the Scientific Advisory Committee for Sanofi (since 2013); the International Cardiovascular and Metabolism Research and Development Portfolio Committee for Novartis; and the AstraZeneca Genomics Advisory Board (2018).

Figures

FIGURE 1
FIGURE 1
CONSORT flowchart showing. Note: 30% drop‐out rate expected between Stage 1 visit 1 and visit two donors as per study design
FIGURE 2
FIGURE 2
Bland–Altman plot of each haemoglobin testing strategy by sex using venous haemoglobin values as the reference test. Note: Dotted light grey lines represent zero bias. Solid red lines represent the mean bias of the testing strategy (middle) and accompanying 95% limit of agreement (LOA; upper and lower) of the mean bias. Dashed blue lines depict proportional bias estimated using linear regression. Men—Post‐donation strategy: N = 5920, 4.3% outside the LOA. Capillary HemoCue: N = 5279, 5.1% outside the LOA. OrSense: N = 4861, 5.7% outside the LOA. Haemospect: N = 4352, 5.5% outside the LOA. Women ‐ Post‐donation strategy: N = 6394, 5.2% outside the LOA. Capillary HemoCue: N = 5724, 5.0% outside the LOA. OrSense: N = 5580, 5.2% outside the LOA. Haemospect: N = 4170, 5.5% outside the LOA [Color figure can be viewed at wileyonlinelibrary.com]
FIGURE 3
FIGURE 3
Scatterplot comparing testing device haemoglobin values to those obtained from venous blood samples by sex [Color figure can be viewed at wileyonlinelibrary.com]
FIGURE 4
FIGURE 4
Receiver operating characteristic curves for each haemoglobin testing strategy at different haemoglobin thresholds by sex. Note: Threshold values are shown in g/L. Sensitivity and specificity of NHSBT method has been superimposed as it only provides a pass/fail result rather than a quantitative readout [Color figure can be viewed at wileyonlinelibrary.com]
FIGURE 5
FIGURE 5
Donation outcomes by testing strategy and sex, per 100 donations standardised to the returning donor population in the COMPARE study. Note: †1 in every 1000 donations for men, and 2 in every 1000 donations for women are incorrectly deferred using the customary NHSBT method [Color figure can be viewed at wileyonlinelibrary.com]
FIGURE 6
FIGURE 6
Percentage difference (95% confidence interval) in donors who would be bled below and deferred above the donation haemoglobin threshold for each testing strategy compared with the standard NHSBT test by sex. Note: P‐values calculated using McNemar's test
See this image and copyright information in PMC

References

    1. Cable RG. Hemoglobin determination in blood donors. Transfus Med Rev. 1995;9:131‐144. - PubMed
    1. Mast AE. Low hemoglobin deferral in blood donors. Transfus Med Rev. 2014;28(1):18‐22. - PMC - PubMed
    1. Commission directive 2004/33/EC implementing directive 2002/98/EC of the European Parliament and of the council as regards certain technical requirements for blood and blood components. Official J Eur Union. 2004;256:32‐40.
    1. Vuk T, Magnussen K, De Kort W, et al. International forum: an investigation of iron status in blood donors. Blood Transfus. 2017;15(1):20‐41. - PMC - PubMed
    1. Zalpuri S, Romeijn B, Allara E, et al. Variations in hemoglobin measurement and eligibility criteria across blood donation services are associated with differing low‐hemoglobin deferral rates: a BEST collaborative study. Transfusion. 2020;60(3):544‐552. - PubMed

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