Statistical analysis of inappropriate results from current Hb screening methods for blood donors

Assessment of the Key Performance Indicator Proposed by NABH in the Blood Centre of a Tertiary Health Care Hospital in Southern India

Quality indicators are tools for continuous improvement to enable the blood center to achieve its standards of the highest quality. Hence, they have to be established and monitored regularly for which NABH (National Accreditation Board for Hospitals) accreditation should be sought for. This study was undertaken to assess the Key Performance Indicators (KPI) through clinical audit quality control study of ten parameters, with a goal to improve and meet the benchmark as defined by NABH. All 10 Key Performance Indicators defined by NABH were analysed prospectively in a tertiary care blood centre of southern India. Parameters were compared to that of bench mark standards. Root cause analysis of all non-conformance parameters were done. Problem were identified and action taken to achieve KPI benchmarks in all deviations. Out of the ten KPI's which were studied, more than 50% meet the quality standards. The ones that did not meet the bench mark were TTI-HIV% which was 0.44%, TTI-Syphilis (RPR)% 0.26%, Number of units received back for discarding 5.96%, PRBC wastage% (on-shelf) was 2.11%, FFP, Cryoprecipitate wastage % (on-shelf) was 2.71%, the mean TAT for crossmatch of emergency PRBC blood was 18.3 min, 41.11% of FFP QC failure failed, Delay in transfusion time beyond 30 min after issue was 19.14%, Donor Deferral rate was 16.36% and TTI Outliers% No. of deviations beyond ± 2SD for HBsAg, HCV, HIV were 14.43%, 12.59% and17.73% respectively. Present study has helped to understand the flaws and problems faced by a tertiary care blood center in sustaining quality. It also actively captured and analysed multiple cross sections of non-conformances.

Impact of a post-donation hemoglobin testing strategy on efficiency and safety of whole blood donation in England: A modeling study

BACKGROUND

Deferrals due to low hemoglobin are time-consuming and costly for blood donors and donation services. Furthermore, accepting donations from those with low hemoglobin could represent a significant safety issue. One approach to reduce them is to use hemoglobin concentration alongside donor characteristics to inform personalized inter-donation intervals.

STUDY DESIGN AND METHODS

We used data from 17,308 donors to inform a discrete event simulation model comparing personalized inter-donation intervals using "post-donation" testing (i.e., estimating current hemoglobin from that measured by a hematology analyzer at last donation) versus the current approach in England (i.e., pre-donation testing with fixed intervals of 12-weeks for men and 16-weeks for women). We reported the impact on total donations, low hemoglobin deferrals, inappropriate bleeds, and blood service costs. Personalized inter-donation intervals were defined using mixed-effects modeling to estimate hemoglobin trajectories and probability of crossing hemoglobin donation thresholds.

RESULTS

The model had generally good internal validation, with predicted events similar to those observed. Over 1 year, a personalized strategy requiring ≥90% probability of being over the hemoglobin threshold, minimized adverse events (low hemoglobin deferrals and inappropriate bleeds) in both sexes and costs in women. Donations per adverse event improved from 3.4 (95% uncertainty interval 2.8, 3.7) under the current strategy to 14.8 (11.6, 19.2) in women, and from 7.1 (6.1, 8.5) to 26.9 (20.8, 42.6) in men. In comparison, a strategy incorporating early returns for those with high certainty of being over the threshold maximized total donations in both men and women, but was less favorable in terms of adverse events, with 8.4 donations per adverse event in women (7.0, 10,1) and 14.8 (12.1, 21.0) in men.

DISCUSSION

Personalized inter-donation intervals using post-donation testing combined with modeling of hemoglobin trajectories can help reduce deferrals, inappropriate bleeds, and costs.

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

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.

Venous sample is superior to repeated skin-prick testing in blood donor haemoglobin second-line screening

BACKGROUND

Blood donor haemoglobin concentration (Hb) is commonly measured from a skin-prick sample. However, the skin-prick sample is prone to preanalytical error and variation, which may lead to false deferrals due to low Hb.

STUDY DESIGN AND METHODS

We assessed the efficacy of two second-line screening models for the evaluation of blood donors failing the initial skin-prick test. In the venous model (n = 305), Hb was measured from a venous sample at the donation site. In the skin-prick model (n = 331), two additional skin-prick samples were measured. All on-site Hb measurements were performed with HemoCue Hb201+ (HemoCue AB) point-of-care (POC) device. Hb in the venous samples was later also determined with a hematology analyzer (Sysmex XN, Sysmex Co.) to obtain the donor's correct Hb. A questionnaire evaluated Blood Service nurses' preferences regarding Hb assessment.

RESULTS

Significantly less donors were deferred from donation with venous model (40%) than with skin-prick model (51%; chi-square test P = 0·004). Only two donors (0·7%) were incorrectly accepted in the venous model. Further, Blood Service nurses preferred venous model over skin-prick model. After the study, the venous model was implemented nationwide, and in the first two months after implementation, the deferral rate due to low Hb decreased from 2·7% to 1·9%.

CONCLUSION

A venous sample for blood donor Hb second-line screening significantly decreased low Hb deferrals compared to repeated skin-prick testing without compromising donor safety. Valuable donations can be recovered by implementing a practical second-line screening model based on venous sampling.

A Comparative Study of Serum Ferritin Levels Among Unfit and Fit Blood Donors

Background:

Cheap methodologies are being utilized by low-resource countries to determine blood donors' fitness. Important hematological biomarkers might have to be evaluated to enhance the use of these methods.

Aims:

The study evaluated the pattern of serum ferritin in 18–24 fit and unfit prospective blood donors (PDBs) and the prevalence of iron store deficiency.

Settings and Design:

This study was a cross-sectional, comparative study which was conducted at the blood donor clinic of the Lagos University Teaching Hospital.

Materials and Methods:

Blood samples were collected by venipuncture into sodium-ethylenediaminetetraacetic acid and plain bottles. The latter was centrifuged and used for ferritin determination via human ferritin enzyme-linked immunosorbent assay test kit, while the former was used for red cell indices analysis using an autoanalyzer.

Statistical Analysis:

Data were analyzed using SPSS version 20, values were presented as mean ± standard deviation, and P ≤ 0.05 was considered statistically significant.

Results:

A total of 263 PDB were recruited into the study consisting of 210 (79%) males and 53 (21%) females, with a mean age of 32.88 ± 8.22. Only 110 (41.8%) of the participants were considered fit, while 153 (58.2%) were unfit using copper sulfate specific gravity. There was no statistically significant difference (P = 0.301) in the mean level of serum ferritin in unfit blood donors (74.5 ± 90.8 μg/L) compared to that of the fit blood donors (61.5 ± 54.5 μg/L). The prevalence of iron store depletion among blood donors in Lagos state was 11.8% (31 of 263) with a higher proportion (7.6%) occurring among unfit donors. However, low levels of serum ferritin (<15 μg/L) were significantly associated with the occurrence of anemia (hemoglobin < 12.5 g/gl) among unit donors (19%; P = 0.05).

Conclusion:

Although serum ferritin depletion appears to be higher in the unfit blood donors, the use of serum ferritin as an index for the screening and determination of PDBs' fitness requires further evaluation.

The Sting of Rejection: Deferring Blood Donors due to Low Hemoglobin Values Reduces Future Returns

Background

Roughly one quarter of short-term temporary deferrals (STTD) of blood donors are low-hemoglobin deferrals (LHD), i.e. STTD due to a hemoglobin (Hb) value falling below a cutoff of 125 g/L for female and 135 g/L for male donors. Since voluntarily donating blood is a prosocial activity, donors may perceive deferral as social exclusion, which can cause social pain, decrease self-esteem, and lead to antisocial behavior. However, little is known about the causal impacts of LHD on donor return.

Study Design and Methods

We conducted a quasi-experiment with 80,060 donors invited to blood drives in the canton of Zurich, Switzerland, between 2009 and 2014. Within a narrow window of Hb values around the predetermined cutoff, the rate of LHD jumps discontinuously. This discontinuous jump allows us to quantify the causal effects of LHD on donor return, as it is uncorrelated with other unobserved factors that may also affect donor return.

Results

We found different behavioral reactions to LHD for female and male donors. Female donors do not react to the first LHD. However, after any repeated LHD, they are 13.53 percentage points (p <0.001) less likely to make at least 1 donation attempt within the next 18 months and make 0.389 fewer donation attempts (p <0.001). Male donors react to the first LHD. They are 5.32 percentage points (p = 0.139) less likely to make at least 1 donation attempt over the next 18 months and make 0.227 (p = 0.018) fewer donation attempts. After any repeated LHD, male donors are 13.30 percentage points (p = 0.004) less likely to make at least 1 donation attempt and make 0.152 (p = 0.308) fewer donation attempts.

Conclusion

LHD have detrimental impacts on donor return, especially if they occur repeatedly - suggesting that avoiding false LHD and helping donors to better cope with them helps to maintain the pool of prospective donors.

Efficiency and safety of varying the frequency of whole blood donation (INTERVAL): a randomised trial of 45 000 donors

BACKGROUND

Limits on the frequency of whole blood donation exist primarily to safeguard donor health. However, there is substantial variation across blood services in the maximum frequency of donations allowed. We compared standard practice in the UK with shorter inter-donation intervals used in other countries.

METHODS

In this parallel group, pragmatic, randomised trial, we recruited whole blood donors aged 18 years or older from 25 centres across England, UK. By use of a computer-based algorithm, men were randomly assigned (1:1:1) to 12-week (standard) versus 10-week versus 8-week inter-donation intervals, and women were randomly assigned (1:1:1) to 16-week (standard) versus 14-week versus 12-week intervals. Participants were not masked to their allocated intervention group. The primary outcome was the number of donations over 2 years. Secondary outcomes related to safety were quality of life, symptoms potentially related to donation, physical activity, cognitive function, haemoglobin and ferritin concentrations, and deferrals because of low haemoglobin. This trial is registered with ISRCTN, number ISRCTN24760606, and is ongoing but no longer recruiting participants.

FINDINGS

45 263 whole blood donors (22 466 men, 22 797 women) were recruited between June 11, 2012, and June 15, 2014. Data were analysed for 45 042 (99·5%) participants. Men were randomly assigned to the 12-week (n=7452) versus 10-week (n=7449) versus 8-week (n=7456) groups; and women to the 16-week (n=7550) versus 14-week (n=7567) versus 12-week (n=7568) groups. In men, compared with the 12-week group, the mean amount of blood collected per donor over 2 years increased by 1·69 units (95% CI 1·59-1·80; approximately 795 mL) in the 8-week group and by 0·79 units (0·69-0·88; approximately 370 mL) in the 10-week group (p<0·0001 for both). In women, compared with the 16-week group, it increased by 0·84 units (95% CI 0·76-0·91; approximately 395 mL) in the 12-week group and by 0·46 units (0·39-0·53; approximately 215 mL) in the 14-week group (p<0·0001 for both). No significant differences were observed in quality of life, physical activity, or cognitive function across randomised groups. However, more frequent donation resulted in more donation-related symptoms (eg, tiredness, breathlessness, feeling faint, dizziness, and restless legs, especially among men [for all listed symptoms]), lower mean haemoglobin and ferritin concentrations, and more deferrals for low haemoglobin (p<0·0001 for each) than those observed in the standard frequency groups.

INTERPRETATION

Over 2 years, more frequent donation than is standard practice in the UK collected substantially more blood without having a major effect on donors' quality of life, physical activity, or cognitive function, but resulted in more donation-related symptoms, deferrals, and iron deficiency.

FUNDING

NHS Blood and Transplant, National Institute for Health Research, UK Medical Research Council, and British Heart Foundation.

Hepcidin/Ferritin Quotient Helps to Predict Spontaneous Recovery from Iron Loss following Blood Donation

BACKGROUND

Iron supplementation is generally recommended for blood donors even though there are inter-individual differences in iron homeostasis.

METHODS

Ferritin levels of repeat donors were compared with first-time donors, retrospectively. Prospectively, we tested 27 male repeat donors for the following parameters at the day of blood donation as well as 1, 3, 7, 10, and 56 days thereafter: ferritin, hepcidin, transferrin, transferrin receptor, hemoglobin, erythropoietin, reticulocytes, hemoglobin in reticulocyte, twisted gastrulation protein homolog 1, and growth differentiation factor-15.

RESULTS

56 days after blood donation, donors' average ferritin dropped to 55% (range 30-100%) compared to the initial value. Of all tested parameters hepcidin showed the highest and most significant changes beginning 1 day after donation and lasting for the whole period of 56 days. Along with ferritin, there was a high variation in hepcidin levels indicating inter-individual differences in hepcidin response to iron loss. Donors with a hepcidin/ferritin quotient < 0.3 regained 60% of their initial ferritin after 56 days, while those with a quotient ≥ 0.3 reached less than 50%.

CONCLUSION

As hepcidin appears to integrate erythropoietic and iron-loading signals, clinical measurement of hepcidin (together with the hepcidin-ferritin ratio) may become a useful indicator of erythropoiesis and iron kinetics.

Portable hemoglobinometer is a reliable technology for the follow-up of venesections tolerance in hemochromatosis

BACKGROUND

The treatment of HFE-related hemochromatosis, one of the most common genetic diseases, is based on phlebotomies whose tolerance is evaluated by regular monitoring of hemoglobin. Using a portable hemoglobinometer (PH) could provide an easy and fast determination of hemoglobin. Therefore, the aim of the present study was to compare, in hemochromatosis patients treated by bloodletting, the hemoglobin concentrations as assayed, on capillary blood, by a PH device and, on venous blood, by a cell counter (CC) device.

METHODS

For a total period of 12 weeks duration, all patients undergoing phlebotomies in the same hospital outpatient unit had hemoglobin determinations both by the HemoCue and by the laboratory's DxH 800 Coulter. To evaluate the sensitivity and specificity of the HemoCue, patients were classified as presenting or not anemia as defined by hemoglobin level below 11 g/dl.

RESULTS

Measurements of hemoglobin were performed in 122 patients. The sensitivity and specificity of PH compared to CC were 100 and 98.1%, respectively. Capillary hemoglobin by PH slightly underestimated venous hemoglobin by CC. The Pearson's correlation coefficient between PH and CC was 0.80 (P<0.0001).

CONCLUSION

PH is a reliable, quick and easy technology, which can be proposed to follow-up the tolerance of venesections in hemochromatosis patients.

Comparison of the accuracy of noninvasive hemoglobin sensor (NBM-200) and portable hemoglobinometer (HemoCue) with an automated hematology analyzer (LH500) in blood donor screening

BACKGROUND

The Hb levels of prospective blood donors are usually determined using a finger prick test. A new noninvasive Hb device has the advantage of not causing any sampling pain. The purpose of this study was to evaluate the accuracy of the noninvasive Hb sensor and to compare its measurements with those of a currently used portable hemoglobinometer.

METHODS

Hb was measured using a noninvasive Hb sensor (NBM-200; OrSense, Israel), a portable hemoglobinometer (HemoCue; HemoCue AB, Sweden), and an automated hematology analyzer (LH500; Beckman Coulter, USA). The correlations between Hb measurements taken by the NBM-200 and HemoCue with those by an automated hematology analyzer were assessed using intraclass correlation coefficients (ICCs). Hb measurements were compared among 3 different Hb level groups.

RESULTS

The mean Hb values of 506 blood donors were 14.1 g/dL by the NBM-200, 14.0 g/dL by the LH500, and 14.3 g/dL by the HemoCue. The correlation between the LH500 and the NBM-200 was substantial (ICC=0.69), while that between the LH500 and the HemoCue agreed almost perfectly (ICC=0.86).

CONCLUSIONS

The possibility to judge to be eligible for donors who are ineligible to donate was substantial when using NBM-200. Even though the NBM-200 has the apparent advantage of noninvasiveness, its use in pre-screening should be given meticulous attention. Since pre-donation testing is crucial to protecting donors' health, complete evaluation of the instrument should be performed prior to use.

Capillary versus venous haemoglobin determination in the assessment of healthy blood donors

BACKGROUND AND OBJECTIVES

To determine the accuracy of fingerstick haemoglobin assessment in blood donors, the performance of a portable haemoglobinometer (HemoCue Hb 201+) was prospectively compared with that of an automated haematology analyzer (Cell-Dyn 4000). Haemoglobin values obtained by the latter were used as the 'true' result.

MATERIAL AND METHODS

Capillary fingerstick samples were assayed by HemoCue in 150 donors. Fingerstick samples from two sites, one on each hand, were obtained from a subset of 50 subjects. Concurrent venous samples were tested using both HemoCue and Cell-Dyn devices.

RESULTS

Capillary haemoglobin values (HemoCue) were significantly greater than venous haemoglobin values (HemoCue), which in turn were significantly greater than venous haemoglobin values by Cell-Dyn (mean ± SD: 14.05 ± 1.51, 13.89 ± 1.31, 13.62 ± 1.23, respectively; P < 0.01 for all comparisons among groups). Nine donors (6%) passed haemoglobin screening criteria (≥ 12.5 g/dl) by capillary HemoCue, but were deferred by Cell-Dyn values (false-pass). Five donors (3%) were deferred by capillary sampling, but passed by Cell-Dyn (false-fail). Substantial variability in repeated fingerstick HemoCue results was seen (mean haemoglobin 13.72 vs. 13.70 g/dl, absolute mean difference between paired samples 0.76 g/dl). Hand dominance was not a factor.

CONCLUSIONS

Capillary samples assessed via a portable device yielded higher haemoglobin values than venous samples assessed on an automated analyzer. False-pass and false-fail rates were low and acceptable in the donor screening setting, with 'true' values not differing by a clinically significant degree from threshold values used to assess acceptability for blood donation.

Evaluation of the validity of a rapid method for measuring high and low haemoglobin levels in whole blood donors

BACKGROUND

Haemoglobin screening methods need to be highly sensitive to detect both low and high haemoglobin levels and avoid unnecessary rejection of potential blood donors. The aim of this study was to evaluate the accuracy of measurements by HemoCue in blood donors.

MATERIALS AND METHODS

Three hundred and fourteen randomly selected, prospective blood donors were studied. Single fingerstick blood samples were obtained to determine the donors' haemoglobin levels by HemoCue, while venous blood samples were drawn for measurement of the haemoglobin level by both HemoCue and an automated haematology analyser as the reference method. The sensitivity, specificity, predictive values and correlation between the reference method and HemoCue were assessed. Cases with a haemoglobin concentration in the range of 12.5-17.9 g/dL were accepted for blood donation.

RESULTS

Analysis of paired results showed that haemoglobin levels measured by HemoCue were higher than those measured by the reference method. There was a significant correlation between the reference method and HemoCue for haemoglobin levels less than 12.5 g/dL. The correlation was less strong for increasing haemoglobin levels. Linear correlation was poor for haemoglobin levels over 18 g/dL. Thirteen percent of donors, who had haemoglobin levels close to the upper limit, were unnecessarily rejected.

DISCUSSION

HemoCue is suitable for screening for anaemia in blood donors. Most donors at Yazd are males and a significant percentage of them have haemoglobin values close to the upper limit for acceptance as a blood donor; since these subjects could be unnecessarily rejected on the basis of HemoCue results and testing with this method is expensive, it is recommended that qualitative methods are used for primary screening and accurate quantitative methods used in clinically suspicious cases or when qualitative methods fail.

Deferral pattern in voluntary blood donors on basis of low hemoglobin and effect of application of digital hemoglobinometer on this pattern

Background:

One of the responsibilities of blood center is to provide safety to blood donors. It is mandatory to screen a blood donor for hemoglobin (Hb) or hematocrit which should not be less than 12.5 g/dl or 38% Hct. Most commonly applied method for hemoglobin estimation is copper sulphate method, but this method has chances of false acceptance as well as false deferral. In order to avoid this chance of error, digital hemoglobinometer is used. This study was planned to analyze effect of application of digital hemoglobinometer for detection of Hb on donors, who are deferred by copper sulphate method.

Materials and Methods:

Total 35,339 voluntary non renumareted altruistic donors were included in this study between the periods of September 2005 to July 2006. Total deferred donors were 8622 (24.39%) and donors deferred due to hemoglobin by copper sulphate method were 4391 (50.92%). Digital hemoglobinometer was applied on 3163 deferred donors (72.03%). Results of digital hemoglobinometer were validated by known controls.

Result:

Digital hemoglobinometer was applied on 3163 donors who were deferred by copper sulphate method. Out of this, donors accepted by digital hemoglobinometer were 1196 (37.01%). Total repeat donors were 629 (52.50%) and first time were 567 (47.40%). Male donors were 891 (74.44%) and females were 305 (25.50%). Donors deferred with digital hemoglobinometer were 2135, out of them 1097 (51.14%) were repeat, 1038 (48.38%) were first time, 1349 (60.79%) were male, 786 (34.47%) donors were female donors. Range of hemoglobin in deferred donors was 7.0 to 12.4 and in accepted donors 12.5 to 16.4.

Conclusion:

By the application of digital hemoglobinometer 37.81% donors were found hemoglobin >12.5 which were deferred with copper sulphate method and unnecessary deferral of donors can be reduced to a great extent. In country like India, where blood supply is always less than the requirement, this new technique may be helpful to increase donor population but cost benefit ratio should be analyzed.

Quality evaluation of four hemoglobin screening methods in a blood donor setting along with their comparative cost analysis in an Indian scenario

Background:

Despite the wide range of methods available for measurement of hemoglobin, no single technique has emerged as the most appropriate and ideal for a blood donation setup.

Materials and Methods:

A prospective study utilizing 1014 blood samples was carried out in a blood donation setting for quality evaluation of four methods of hemoglobin estimation along with cost analysis: Hematology cell analyzer (reference), HCS, CuSO4 method and HemoCue.

Results:

Mean value of HemoCue (mean ± SD = 14.7 ± 1.49 g/dl) was higher by 0.24 compared to reference (mean ± SD = 13.8 ± 1.52 g/dl) but not statistically significant ( P > 0.05). HemoCue proved to be the best technique (sensitivity 99.4% and specificity 84.4%) whereas HCS was most subjective with 25.2% incorrect estimations. CuSO4 proved to be good with 7.9% false results. Comparative cost analysis of each method was calculated to be 35 INR/test for HemoCue, 0.76 INR /test for HCS and 0.06-0.08 INR /test for CuSO4.

Conclusion:

CuSO4 method gives accurate results, if strict quality control is applied. HemoCue is too expensive to be used as a primary screening method in an economically restricted country like India.

Hemoglobin estimation by the HemoCue® portable hemoglobin photometer in a resource poor setting

Background

In resource poor settings where automated hematology analyzers are not available, the Cyanmethemoglobin method is often used. This method though cheaper, takes more time. In blood donations, the semi-quantitative gravimetric copper sulfate method which is very easy and inexpensive may be used but does not provide an acceptable degree of accuracy. The HemoCue^® hemoglobin photometer has been used for these purposes. This study was conducted to generate data to support or refute its use as a point-of-care device for hemoglobin estimation in mobile blood donations and critical care areas in health facilities.

Method

EDTA blood was collected from study participants drawn from five groups: pre-school children, school children, pregnant women, non-pregnant women and men. Blood collected was immediately processed to estimate the hemoglobin concentration using three different methods (HemoCue^®, Sysmex KX21N and Cyanmethemoglobin). Agreement between the test methods was assessed by the method of Bland and Altman. The Intraclass correlation coefficient (ICC) was used to determine the within subject variability of measured hemoglobin.

Results

Of 398 subjects, 42% were males with the overall mean age being 19.4 years. The overall mean hemoglobin as estimated by each method was 10.4 g/dl for HemoCue, 10.3 g/dl for Sysmex KX21N and 10.3 g/dl for Cyanmethemoglobin. Pairwise analysis revealed that the hemoglobin determined by the HemoCue method was higher than that measured by the KX21N and Cyanmethemoglobin. Comparing the hemoglobin determined by the HemoCue to Cyanmethemoglobin, the concordance correlation coefficient was 0.995 (95% CI: 0.994-0.996, p < 0.001). The Bland and Altman's limit of agreement was -0.389 - 0.644 g/dl with the mean difference being 0.127 (95% CI: 0.102-0.153) and a non-significant difference in variability between the two measurements (p = 0.843). After adjusting to assess the effect of other possible confounders such as sex, age and category of person, there was no significant difference in the hemoglobin determined by the HemoCue compared to Cyanmethemoglobin (coef = -0.127, 95% CI: -0.379 - 0.634).

Conclusion

Hemoglobin determined by the HemoCue method is comparable to that determined by the other methods. The HemoCue photometer is therefore recommended for use as on-the-spot device for determining hemoglobin in resource poor setting.

Cost and effectiveness comparison of two methods for screening potential blood donors for anaemia in Vietnam

AIM/OBJECTIVE

To compare the cost and effectiveness of Copper Sulphate (CS) and HemoCue (HC) methods for screening blood donors for anaemia.

BACKGROUND

Robust information from developing countries about cost and effectiveness of anaemia screening methods for blood donors is scarce. In such countries there are widespread shortages of blood, so the most cost-effective method should maximise blood supply without compromising donor safety.

METHODS

Economic data (e.g. staff time, equipment and buildings) were collected from direct observation of procedures and purchase data from Hanoi's Central Blood Bank administrative department. A framework for comparing the cost and effectiveness of anaemia screening methods was developed and a cost per effective (i.e. usable and accurate) test was generated for each method.

RESULTS

Samples from 100 potential donors from the Hanoi Central Blood Bank (static) and 198 from two mobile units were tested. The mean probability of an ineffective anaemia test was 0·1 (0·05-0·2). The average cost of an HC test was $0·75 (static $0·61 and mobile $0·89) and a CS test was $0·31 (static $0·17 and mobile $0·45). The difference between static and mobile units was predominantly due to transport costs; the difference between the two methods was predominantly due to the HC microcuvettes.

CONCLUSION

In this setting the CS yields greater value for money than the HC method for screening blood donors. The relative cost and effectiveness of CS and HC may be different in places with higher staff turnover, lower test accuracy, higher anaemia prevalence or lower workload than in Vietnam.

Evidence-based criteria for the care and selection of blood donors, with some comments on the relationship to blood supply, and emphasis on the management of donation-induced iron depletion

Blood Services, which, in the UK, spend over 0.5% of the NHS budget, are generally subject to quality, regulatory, economic and political authority. As only persons in good health should give blood, Services have refined donor selection criteria and aim to base them on evidence; but they also have to balance the number of donations collected with product demand. Applying selection criteria inevitably leads to deferrals, which donors experience very negatively. Compared with successful donors, even temporary deferrals reduce return rates significantly, especially of first attenders. In order to encourage donor return and sustain supplies, selection criteria should be optimal. However, a major tool for managing patients--evidence from randomized controlled trials (RCTs)--cannot apply to donor selection, so criteria have to be defined by alternatives, such as clinical studies, epidemiology and even what experts deem to be pathophysiologically feasible. The recommended volume of blood taken from each donor at each attendance (450 mL, which was based on old studies) was increased because of greater processing losses (buffy-coat derived platelets, leucofiltration etc.). Although faint rates and donation-induced iron depletion are reduced by lowering bleeding volume and bleeding less frequently, other optimizing strategies including iron supplementation have been trialled and could be enhanced by more RCTs. Better but more complex indicators of donor iron status than one-off Hb thresholds are possible. Regulators and decision-makers must encourage more studies. This review does not consider aphaeresis donors of blood components other than red cells in detail, or the prevention of transfusion-transmitted infections.

Evaluation of four rapid methods for hemoglobin screening of whole blood donors in mobile collection settings

INTRODUCTION

Predonation hemoglobin measurement is a problematic requirement in mobile donation settings, where accurate determination of venous hemoglobin by hematology analyzers is not available.

OBJECTIVE

We have evaluated hemoglobin screening in prospective donors by the semiquantitative copper sulphate test and by capillary blood samples analyzed by three portable photometers, HemoCue, STAT-Site MHgb, and the CompoLab HB system.

METHODS

Capillary blood samples were obtained from 380 donors and tested by the copper sulphate test and by at least one of the named portable photometers. Predonation venous hemoglobin was also determined in all donors using a Coulter Max-M analyzer.

RESULTS

The three photometers provided acceptable reproducibility (CV below 5%), and displayed a significant correlation between the capillary blood samples and the venous hemoglobin (R2 0.5-0.8). HemoCue showed the best agreement with venous hemoglobin determination, followed by STAT-Site MHgb, and the CompoLab HB system. The copper sulphate test provided the highest rate of donors acceptance (83%) despite unacceptable hemoglobin levels, and the lowest rate for donor deferral (1%) despite acceptable hemoglobin levels. The percentage of donors correctly categorized for blood donation by the portable hemoglobinometers was 85%, 82%, and 76% for CompoLab HB system, HemoCue and STAT-Site, respectively.

CONCLUSION

Our data suggest that hemoglobin determination remains a conflictive issue in donor selection in the mobile setting. Without appropriate performance control, capillary hemoglobin screening by either the copper sulphate method or by the novel portable hemoglobinometers could be inaccurate, thus potentially affecting both donor safety and the blood supply.

Evaluation of hemoglobin of blood donors deferred by the copper sulphate method for hemoglobin estimation

INTRODUCTION

The copper sulphate (CuSO4) specific gravity test for Hb screening tends to give inappropriate failures. This prompted us to compare it with alternate screening methods.

AIM

To study the impact of inaccuracy of CuSO4 method on donor deferral.

METHODS

Capillary and venous blood samples of 400 potential blood donors failing the primary Hb screening using appropriately standardized CuSO4 test (specific gravity 1.053) were tested by Hemocue photometer, the Hb colour scale, Cyanmethemoglobin method as well as the automated hematology analyser, which was considered as the standard reference method.

RESULTS

One hundred and sixteen donors (29%) who failed the CuSO4 test had true Hb levels >12.5 g/dl. The Hb levels of 131 (32.8%) deferred donors were between 12 and 12.5 g/dl. The sensitivity of Hemocue, Hb colour scale and Cyanmethemoglobin was 99%, 97% and 96% and their specificity was 45%, 93% and 46%, respectively. The positive predictive values (PPV) of Hemocue and Cyanmethemoglobin methods were low (43% and 44%, respectively) but their negative predictive values (NPV) were high (99%, and 97%, respectively). The Hb colour scale had an overall best performance with a PPV of 96% and NPV of 95%.

CONCLUSION

The Hemoglobin colour scale which is inexpensive, convenient for field testing and has the overall best performance, is the most suitable for donor Hb screening. Since its readability is 12 g/dl, lowering the donor Hb threshold to 12 g/dl should be actively considered.

Selection of whole-blood donors for hemoglobin testing by use of historical hemoglobin values

BACKGROUND

Usually, a predonation hemoglobin (Hb) measurement must precede blood donation. Hb values of a donor's previous donation might be used for selecting a subgroup in which predonation Hb measurements are unnecessary.

STUDY DESIGN AND METHODS

Only donors with historical Hb values below 129 or 139 g per L for female and male donors, respectively, underwent venous Hb measurement before phlebotomy with an automated hematology analyzer. All other donor phlebotomies were collected without initial Hb testing. Hb values from diversion samples from 81,913 consecutive donors between May 2003 and November 2005 were subsequently analyzed as representing their present values. Donors were grouped according to interdonation intervals of less than 6, 6 to 11, 12 to 23, and 24 months or more.

RESULTS

The arithmetic mean deviation between historical and present Hb values was between -0.3 and +1.8 g per L for each group (mean deviation, 5.2-6.7 g/L). Not testing selected donors spared 77.7 percent from a prephlebotomy Hb measurement and showed a specificity of 29 percent. Sensitivities for detection of donors below Hb limits (between 56% and 67% for the different subgroups) and donors with Hb values below 110 g per L (82%-88%) were at least comparable to capillary Hb screening. A total of 4.8 percent of donors were phlebotomized with values below 125 and 135 g per L, whereas only 0.016 percent of donors were bled despite Hb levels below 110 g per L.

CONCLUSION

Selecting donors for a current Hb measurement based upon their last whole-blood predonation Hb value is a useful method, even after prolonged interdonation intervals.

A noninvasive strategy for screening prospective blood donors for anemia

BACKGROUND

The reliability of capillary hemoglobin (Hb) as an indicator for eligibility to donate blood is discussed controversially. Therefore, a noninvasive alternative with acceptable predictive values was established and evaluated.

STUDY DESIGN AND METHODS

Donor candidates were selected according to their Hb level. The first donation was performed 6 weeks after this selection step. A venous blood sample was collected from all donors at the end of their donation and a postdonation Hb determination was performed. Donors with acceptable postdonation Hb values were permitted to donate next time without any predonation Hb measurement. Donors with low postdonation Hb values were permitted to donate only after a venous Hb measurement had shown an acceptable value. Sensitivity and specificity were determined by comparing the gold standard (i.e., venous Hb measurement) with the presented method of Hb estimation for 19,534 donors.

RESULTS

Taking the postdonation Hb as an indicator for eligibility saved 97 percent of donors from being tested unnecessarily by capillary Hb measurement. This procedure resulted in a specificity of 92.6 percent and a sensitivity of 37.9 percent for Hb cutoff levels of 135 and 125 g per L for men and women, respectively. The sensitivity increased rapidly to 100 percent for Hb levels below 105 g per L. The average deviation from true Hb level was 6 g per L.

CONCLUSION

The presented noninvasive method distinctly saves time and expenditure without endangering blood donors.

Hemoglobin screening in prospective blood donors: Comparison of different blood samples and different quantitative methods

Portable photometers are increasingly used for hemoglobin screening in blood centers. In a total of 500 unselected prospective blood donors, venous hemoglobin concentrations were measured using a hematology analyzer, and fingerstick hemoglobin concentrations were measured on both a HemoCue B and a Biotest hemoglobin photometer. In 100 of the donors, earstick hemoglobin levels were also measured on the HemoCue system. The mean hemoglobin levels in the fingerstick samples were slightly higher than those in the venous samples. The deviation exceeded the limit of +/-10g l(-1) in 9% of samples tested by HemoCue and in 20% of those investigated by Biotest. The use of earstick samples led to considerable overestimation of the actual hemoglobin concentration.