|Year : 2012 | Volume
| Issue : 4 | Page : 423-431
External quality assessment in blood group serology in the World Health Organization South-East Asia Region
Bureau of Laboratory Quality Standards, Department of Medical Sciences, Ministry of Public Health, Thailand
|Date of Web Publication||25-May-2017|
Bureau of Laboratory Quality Standards, Department of Medical Sciences, Ministry of Public Health
Background: The quality of blood transfusion services (BTS) is essential for the treatment of patients who need blood or blood products. BTS involve several steps, including the acquisition of the donor’s blood, blood grouping, unexpected antibody screening, blood storage, transfusion, etc. There is a need to check the effectiveness of all elements in the BTS can be assessed and monitored by an external quality assessment.
Aim: To assess and evaluate the performance of ABO and Rh(D) blood grouping and unexpected antibody screening of the selected World Health Organization (WHO) South-East Asia Region Member country laboratories.
Methods: WHO Collaborating Centre on Strengthening Quality of Health Laboratories (Thailand) organized a regional external quality assessment scheme for blood group serology (REQAS-BGS) between 2002 and 2008 for laboratories in countries of the WHO South-East Asia Region. Test items for ABO and Rh(D) blood groupings and unexpected antibody screening and identification were distributed three cycles per year to BTS laboratories in Bangladesh, Bhutan, India, Indonesia, Maldives, Myanmar, Nepal, Sri Lanka and Thailand. By the end of the project, a total of 20 BTS laboratories had participated for differing lengths of time.
Results: It was found that 87.5%, 93.3%, 81.3%, 92.3%, 100% and 87.5% of laboratories returned the test results in 2002, 2003, 2004, 2006, 2007 and 2008, respectively. Laboratories with excellent quality or a trend of quality improvement for ABO and Rh(D) blood grouping, unexpected antibody screening and identification during the six years were 60% (12/20), 50% (10/20), 52.9% (9/17) and 81.8% (9/11), respectively. At the initiation of the scheme, most laboratories were using substandard methods for ABO and Rh blood groupings, i.e. performing only direct blood grouping alone but subsequently adopted the standard methods, i.e. performing both direct and reverse blood groupings.
Conclusion: REQAS-BGS in South-East Asia countries has been useful for assessing, monitoring and improving the quality of testing. Challenges such as high costs and regulatory requirements for international shipment of blood samples could be solved by amending the regulation(s) for shipment, or establishing a national EQAS.
Keywords: Regional external quality assessment scheme (REQAS), blood transfusion services, laboratories, quality, ABO, Rh(D) blood grouping, unexpected antibody screening and identification.
|How to cite this article:|
Soisangwan P. External quality assessment in blood group serology in the World Health Organization South-East Asia Region. WHO South-East Asia J Public Health 2012;1:423-31
|How to cite this URL:|
Soisangwan P. External quality assessment in blood group serology in the World Health Organization South-East Asia Region. WHO South-East Asia J Public Health [serial online] 2012 [cited 2021 Apr 21];1:423-31. Available from: http://www.who-seajph.org/text.asp?2012/1/4/423/207044
| Introduction|| |
The quality of laboratory investigation results is essential for the treatment of patients, monitoring the progress of disease, and disease prevention and surveillance. The quality of the results in the blood transfusion services (BTS) is critical since the human blood product is directly transfused to patients. Any error in the test result (false negative or false positive) can have serious consequences including death of the recipients. To achieve a continuous quality system in BTS, the effectiveness of all critical associated elements should be assessed, using both internal and external mechanisms. Internal assessment can be done by the use of batch controls, staff competency testing and audits. But evaluation of the whole process in a laboratory, requires an external quality assessment (EQA). EQA can be conducted by delivering test items of known compositions that closely simulate the clinical materials to participating health laboratories and subsequently comparing their results. EQA has several objectives: (i) assess laboratory performance and the ability to determine the correct results; (ii) identify any errors in the laboratory; (iii) stimulate laboratory personnel to improve their performance and the use of standard methods; and (iv) encourage the establishment and implementation of quality systems with the relevant standards.,
To minimize errors in the blood banking procedures, the WHO’s Regional office for South-East Asia has been implementing effective quality assurance for BTS in Member countries since 1998. This external quality assessment scheme (EQAS) is recognized as an important tool for laboratory quality improvement. EQAS data are also recognized by accreditation bodies as important elements for meeting quality standards for laboratory quality as per ISO 15189 and ISO/IEC 17025.
WHO EQA schemes have been established in the main areas of testing in transfusion laboratory practice by the United Kingdom National External Quality Assessment Service (UK-NEQAS). Because of the absence of national EQAS in SEAR countries, a regional EQAS was initiated by WHO’s Regional office for South-East Asia to create awareness among the countries and to provide them with technical support to set up and improve the quality of their performance. Accordingly, a Regional External Quality Assessment Service in Blood Group Serology (REQAS-BGS) was organized in 2002 by the Bureau of Laboratory Quality Standards (BLQS), Department of Medical Sciences, Thailand (WHO Collaborating Centre on Strengthening Quality of Health Laboratories) to strengthen BTS in SEAR countries. All countries participated, except the Democratic People’s Republic of Korea and Timor-Leste since these two countries lacked BTS and experienced difficulties with the shipment route of the test items. The aim of the REQAS-BGS project was to evaluate the performance of the laboratories for ABO and Rh blood grouping and unexpected antibody screening and identification of the participating laboratories during 2002–2008.
| Materials and methods|| |
In this cross-sectional, retrospective study in a 20 laboratories from nine SEAR countries participated. Each laboratory was given a confidential code number, which was used for performance evaluation reporting of data results. Data on evaluation were made available only to the respective participating laboratory n and to the coordinator at the WHO South-East Asia Regional Office (SEARO). A breakdown of the laboratories participating in the EQA scheme is shown in [Table 1].
|Table 1: Breakdown of reports of the total 20 participating laboratories per distribution cycle|
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The packed red cells and converted sera used in the preparation of the test items were provided by the National Blood Center, Thai Red Cross Society (the WHO Collaborating Centre for Training in Blood Transfusion Medicine) They were tested negative for HBV, HCV and HIV infections and syphilis. The test items were prepared for samples of ABO and Rh(D) blood groupings and unexpected antibody screening test (screening) and identification.
For each distribution cycle, three sets of the test items (red blood cell suspensions and corresponding ABO blood group sera) were distributed to the designated laboratories. Three serum samples (negative or positive for a single or mixed unexpected antibody) for screening and identification were also sent in the same shipment. The test sets were dispatched 15 times, three distribution cycles per year during 2002–2008, to each laboratory by courier in non-cold package condition [Table 1]. Participating laboratories in India received the test items through SEARO during distribution cycles 3–15. Details of the test items distributed are shown in [Table 2].
|Table 2: Details of the test items distributed to participating laboratories|
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The participating laboratories were requested to conduct only the tests currently available in their routine services. Laboratory performance evaluation was based on the status of report return within the closing date, completeness of the test data, the standard method for the test, patterns and degrees of cell agglutination, consistency of agglutination pattern, blood group interpretation and detection, and type of unexpected antibody. The results were compared with the consensus modes derived from the Thai-NEQAS results. Professional judgment by the Expert Committee (comprising the experts from the Thai National Red Cross Society, Deans of the Faculty of Medical Technology and Faculty of Allied Health Sciences of the Thai universities, etc.) was used for the final decision when consensus mode could not be calculated. The REQAS test items were the same sample sets organized for the Thai-NEQAS. The overall scores for performance evaluation of each testing were calculated from the results of the three test items in each distribution cycle. A full score for each testing was 4.0. Quality ranking was based on the full score, i.e. excellent (4.0), very good (3.5–3.99), good (3.0–3.49?), borderline (2.5–2.99), and unacceptable (< 2.49).
A performance evaluation report for each distribution cycle with suggestions and comments for improvement was submitted to the individual participants. A summary report, which included the data of all participants’ performance and types of reagents, was also dispatched to all participants for review and comparison of their performance with the others. To ensure confidentiality, participating laboratories received a summary of the evaluation report without mentioning names of the laboratories.)
| Results|| |
At the beginning of the project, 15 laboratories from nine countries participated. Two additional laboratories from Bangladesh and one from Maldives joined the project to replace those that withdrew at the 8th, 9th and 10th cycle. The total number of participating laboratories in the REQAS-BGS project was 20 [Table 1]. Because certain laboratories did not always receive the test items, mainly due to customs clearance problems, the percentage of laboratories that returned reports was calculated based on those that received the test items, not on the total number of delivery cycles. It was found that 14 of 20 (70%) laboratories returned results for every set of tests received. Two laboratories reported on two tests (ABO and Rh blood grouping), 7 laboratories reported on three tests (ABO, Rh blood grouping and unexpected antibody screening) and 11 reported on all four tests (ABO, Rh blood grouping, unexpected antibody screening and identification) [Table 3].
|Table 3: Details of tests reported by participating laboratories for the performance evaluation|
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Test items showing mixed-field agglutina-tion, i.e. A3 and B subgroups, were sent to participating laboratories. Only 1 of 14 labora-tories reported the correct A3 subgroup result, the remainder reporting A blood group without the mixed-field agglutination, and while all laboratories identified B blood group, only 2 reported the correct subgroup.
Performance evaluation was calculated based on the system used for the Thai national EQAS in blood group serology currently conducted by BLQS for individual testing. The evaluation method was developed by the Bureau of Laboaratory Standards accredited according to ISO/IEC 17043 by NATA, Australia. Participating laboratories followed testing manual. For ABO blood grouping, three laboratories showed consistently excellent quality for all cycles while four had unacceptable performance in at least one distribution cycle caused by either the use of a substandard method (cell grouping only), incorrect ABO blood grouping, inconsistent results between cell and serum groupings, or incomplete records of the results in the report form. For Rh(D) blood grouping, two laboratories showed consistently excellent quality for all cycles, whereas 11 had unacceptable performance in at least one distribution cycle. The main causes of the errors were the use of a substandard method to identify weak-D, incorrect Rh(D) blood group, or incomplete records of the results [Table 4].
|Table 4: Number of laboratories with unacceptable quality and the main causes of the errors|
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Performance evaluation for unexpected antibody screening showed that 3, 6 and 11 laboratories reported on no, some and all distribution cycles, respectively. Of the 11 complete reports, the results of 3 laboratories were excellent and 8 were of unacceptable quality. The major cause of errors was false-negative results. The ratio of negative to false positive in all errors was 21:4. Only three laboratories successfully identified the unexpected antibody for all distribution cycles, 8 laboratories reported for some distribution cycles and 9 did not report. Four of the 6 laboratories that only returned reports in certain distribution cycles had excellent quality for all returned results. The unacceptable quality was due to false-positive, false-negative, unidentified and reported mixed types of antibody reports.
The status of the quality system in each laboratory was determined by analysing the quality ranking of each testing. The status was classified into three groups, i.e. excellent quality for all cycles; showed a trend of quality improvement; and showed no significant quality improvement. The number of laboratories classified into each group is shown in [Table 5].
|Table 5: Summary of the quality status of laboratories from the performance evaluation results (Answer: right)|
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| Discussion|| |
The REQAS-BGS project was first initiated in SEAR in 2002 under the auspices of SEARO. A major challenge encountered was the shipment of the test items to certain countries due to regulations relating to the importation of potentially infectious materials, and to infrequent flights from Bangkok to the destination. In addition, multiple steps to clear the test samples from customs, despite prior arrangement of the delivery process in accordance with the International Air Transport Association (IATA) regulations, resulted in delayed deliveries, non-deliveries and deterioration of the test samples. These delays were reduced in later cycles, which may have been due to better planning and management of the delivery schedules and more awareness and experience of the individuals involved. Moreover, the delivery of batch materials to a designated collaborator for forwarding to participating laboratories in the same country would significantly reduce transportation costs as well as the delivery time.
Although the test items were shipped outside the cold chain, we carried out random checks on the homogeneity and stability of the aliquots stored or transported at room temperature in all 15 distribution cycles, to ensure that the samples were still acceptable if they reached their destination five days after dispatch.
All the 20 BTS laboratories nominated to participate in the project were well-established with responsibility for the supply of blood products within their respective countries. However, they are not representative of all laboratories in the country in the majority of cases. Their performance evaluation in the REQAS-BGS project reflects their current and potential competency in BTS, and should be used to promote a fully functioning quality system for the acquisition and transfusion of the blood products needed by the patients.
The REQAS-BGS project involved the performance evaluation of four routine tests in BTS, i.e. ABO and Rh(D) blood grouping, and unexpected antibody screening and identification. Only 11 of 20 laboratories from seven Member countries – Bangladesh, Bhutan, India, Indonesia, Myanmar, Sri Lanka and Thailand – provided results on all the four tests. Furthermore, not all laboratories performed the standard ABO blood grouping procedures (both cell and serum grouping), either because they lacked the standard cells or because they were unable to differentiate the weak-D grouping. The latter is essential to prevent the transfusion of weak-D blood to a Rh-negative patient which would result in production of the corresponding antibodies. Since the five laboratories that could not correctly identify the weak-D blood group probably performed only the immediate spin method, it is recommended that the indirect antiglobulin test be used for correct blood group identification. This test is needed for cross-matching in all BTS laboratories.
With regard to the test items with mixed-field agglutination, initially only 1 reported the correct A3 and 2 laboratories reported the correct B subgroups. However, after receiving the evaluation results, most laboratories reported the correct results in subsequent delivery cycles. This showed that the BTS laboratories could improve their competency for blood groups with irregular reactions.
BTS laboratories must be able to screen and identify unexpected antibodiesin patients in order to select blood products without the corresponding antigen. This is essential to avoid any transfusion reaction or antibody responses that may result in further difficulty in selecting blood products, especially for patients with thalassemia., In this study, unexpected antibody screening test could be performed by 18 participating laboratories, among which 11 could perform the antibody identification. Nine laboratories prepared their own screening cells but only 2 of them reported the correct results. False-negative results, especially anti-Mia, were reported by laboratories that did not have the screening cells for the antibody. Since anti-Mia is common in Asian populations, screening cells that can detect the antibody should be available in BTS laboratories in SEAR.,, The REQAS-BGS project stimulated laboratory quality in the participating BTS since many of them have started to procure the appropriate screening and panel cells for their routine use, and have improved the quality of their services by evaluating the root causes of error. However, it is expected that the cost would be significantly reduced if laboratories could prepare their own cells since commercial cells are expensive and normally short-lived. The preparation of standardized cells should be obtainable from the selected local donor panel and this would facilitate the use of the standard method of blood grouping and provide an easy and low-cost supply of the standard cells.
Even though some laboratories reported the correct BGS results, the number of test items was small compared with the number of the samples routinely tested in which an error could occur. Samples that give inclusive results by cell grouping alone need to be retested with the serum grouping technique. Therefore, an appropriate quality system must be established for most accurate and efficient laboratories.
Continuous training in both quality and academic aspects of BTS has been provided to laboratories since the initiation of the quality management training project by SEARO in 2001. However, a number of BTS still require quality improvement. Indeed, the WHO global database on blood safety summary report 2011 indicates that 47% of donations are tested in laboratories without quality assurance.
Since 2002, BTS staff from 9 of the 11 SEAR Member countries have received WHO grants for training on the establishment of EQAS in BGS and laboratory quality systems. These countries should thus have sufficient knowledge and experience to establish their own EQAS rather than relying on regional or international quality assessment networks. This would not only provide all local laboratories with quality performance assessment and an overall BTS quality management record at the national level, but also future planning of quality improvement by policy-makers.
Presently, Bhutan has begun to provide national EQAS in BGS. India has EQAS for blood banking, although this service is available only for transfusion-transmitted infectious markers. Some Member countries, such as India, Indonesia and Thailand, have already established strong laboratory quality systems as well as an accreditation body, which could facilitate and promote the improvement of quality systems in sister countries.
WHO has been promoting quality assurance in countries of the Region since the 1980s. Several consultations and workshops have stimulated countries to practise quality assurance with emphasis on internal quality control and EQAS.
| Conclusions|| |
The results of our project point to the importance of quality systems and continuous quality assessment, both internal and external, in BTS laboratories. The limitations and obstacles in organizing REQAS should encourage policy-makers and responsible institutions to initiate EQAS at the national instead of the regional level. The retrospective data can also be used to follow up improvements in the BTS quality systems to sustain the success of participating laboratories in the REQAS-BSG project.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]