British Committee For Standards In Haematology Guidelines Research Articles

Prophylaxis and treatment of venous thromboembolism in cancer patients: a systemic review and critical appraisal of clinical practice guidelines

: Venous thromboembolism (VTE) is the second leading cause of death in patients with cancer and many organizations have published guidelines to help clinicians in prophylaxis and treatment with VTE in cancer patients. However, the quality of different guidelines remains unclear. In this study, we aimed to explore score and provide a whole picture of the current guidelines. Clinical guidelines and consensus statements in English to July 2017 were searched using MEDLINE via PubMed, EMBASE and some websites of guideline organizations. The guidelines containing recommendations on the prophylaxis and treatment with VTE in cancer patients were included. Three reviewers appraised the quality of the included guidelines by using Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. Six domains with 23 items were appraised and standardized averages were calculated as the final scores in every domain. Of 2,335 citations identified, 13 guidelines were included in this study. Associazione Italiana di Oncologia Medica (AIOM), British Committee for Standards in Haematology (BCSH) and French national guideline were regard as “recommended for use with some modification” while the others were “strongly recommended for use in practice”. Most included guidelines scored high in domain 1 (scope and purpose) and domain 2 (stakeholder involvement), but scored poorly in domain 5 (applicability). The recommendations were consistent in general among the included guidelines. Low molecular weight heparin (LMWH) was the major choice for the prophylaxis and treatment but the duration for the long-term treatment for VTE was controversy and the guidelines with high quality tended to recommend 3 months. Apart from the BCSH guidelines, direct acting oral anticoagulants (DOACs) were not recommended on prophylaxis or treatment. The guidelines on VTE in cancer patients were of relative high quality. More effort is needed to decrease the gap between the practice and guideline. DOACs seem to be potential candidate when clinicians are reluctant to use LMWH, but more researches must be performed.

Prophylaxis and treatment of venous thromboembolism in cancer patients: a systemic review and critical appraisal of clinical practice guidelines

Venous thromboembolism (VTE) is the second leading cause of death in patients with cancer and many organizations have published guidelines to help clinicians in prophylaxis and treatment with VTE in cancer patients. However, the quality of different guidelines remains unclear. In this study, we aimed to explore score and provide a whole picture of the current guidelines. Clinical guidelines and consensus statements in English to July 2017 were searched using MEDLINE via PubMed, EMBASE and some websites of guideline organizations. The guidelines containing recommendations on the prophylaxis and treatment with VTE in cancer patients were included. Three reviewers appraised the quality of the included guidelines by using Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. Six domains with 23 items were appraised and standardized averages were calculated as the final scores in every domain. Of 2,335 citations identified, 13 guidelines were included in this study. Associazione Italiana di Oncologia Medica (AIOM), British Committee for Standards in Haematology (BCSH) and French national guideline were regard as “recommended for use with some modification” while the others were “strongly recommended for use in practice”. Most included guidelines scored high in domain 1 (scope and purpose) and domain 2 (stakeholder involvement), but scored poorly in domain 5 (applicability). The recommendations were consistent in general among the included guidelines. Low molecular weight heparin (LMWH) was the major choice for the prophylaxis and treatment but the duration for the long-term treatment for VTE was controversy and the guidelines with high quality tended to recommend 3 months. Apart from the BCSH guidelines, direct acting oral anticoagulants (DOACs) were not recommended on prophylaxis or treatment. The guidelines on VTE in cancer patients were of relative high quality. More effort is needed to decrease the gap between the practice and guideline. DOACs seem to be potential candidate when clinicians are reluctant to use LMWH, but more researches must be performed.

Clinical usefulness of the dilute Russell viper venom time test for patients taking warfarin

Warfarin use often causes false-positive results in the dilute Russell viper venom time test (DRVVT). Thus, three sets of guidelines-those presented by the International Society on Haemostasis and Thrombosis (ISTH), the British Committee for Standards in Haematology (BCSH), and the Clinical and Laboratory Standards Institute (CLSI)-are advocated. We evaluated the clinical usefulness of the testing methods recommended in these three guidelines using laboratory samples. Of the 242 samples from patients using warfarin, 38 were positive for lupus anticoagulant (LA). After adding normal pooled plasma (NPP) as recommended in the ISTH, BCSH, and CLSI guidelines, the number of samples testing positive for LA decreased to 13, 18, and 19, respectively. The number of samples with inconsistent results between the activated partial thromboplastin time and mixing test, and the DRVVT following the ISTH, BCSH, and CLSI guidelines were four of 205 (1.9%), 15 of 242 (6.2%), and 17 of 242 (7.0%), respectively. In patients with an international normalized ratio (INR)≥3.0, 11 of 37 (29.7%) and 12 of 37 (32.4%) samples showed inconsistent results according to the BCSH and CLSI guidelines, respectively. The accuracy of the DRVVT result may thus decrease in markedly anticoagulated patients.

Guidelines on transfusion for fetuses, neonates and older children.

Guidelines on transfusion for fetuses, neonates and older children.

Clinical Impact of Bone Marrow Morphology for the Diagnosis of Essential Thrombocythemia: Comparison Between the British Standards (BCSH) and the WHO Criteria

Background Accurate diagnosis of essential thrombocythemia (ET) continues to be a challenging issue for both hematopathologists and clinicians. Diagnosis is usually performed by applying either the 2014 British Committee for Standards in Haematology (BCSH) guidelines or the 2008 World Health Organization (WHO) criteria. While the WHO classification requires bone marrow morphology (BM) as a major criterion, the BCSH guidelines allow diagnosis also based solely on clinical symptoms and is more focused on exclusion of the other subtypes of myeloproliferative neoplasia (MPN). However, prefibrotic/early stages of primary myelofibrosis (prePMF) may also present with thrombocytosis, while failing to meet the diagnostic signs and symptoms characterizing overt PMF. Moreover, a small fraction of polycythemia vera (PV) patients may present with low hemoglobin and hematocrit levels, but a platelet count in keeping with BCSH- and WHO-defined ET, thus mimicking phenotypically ET at onset (masked PV). Clinical outcome in prePMF patients is considerably worse than in ET patients, while treatment strategies are likely to change for prePMF patients with the use of interferon-alpha or JAK1/2-inhibitors.Aims The aim of this study was to investigate the prognostic relevance of BM morphology for ET diagnosis as underscored by the WHO classification versus the first set of the BCSH criteria that do not include BM evaluation.Methods A clinic-pathological database including 450 MPN patients was created by clinicians and hematopathologists from a major Austrian center. Treatment-naive BM biopsies were centrally re-reviewed by three of the authors, who were completely blinded to initial data (except for age and gender). Follow-up data, including clinical course and mutation status, were analyzed after the completion of the histopathology review. For purpose of this study we selected two cohorts of ET patients presenting with a sustained platelet count > 450x10^9/L: (1) 209 ET patients in accordance with the diagnostic requirements of the BCSH (A1-A3) that included no BM biopsy examination. (2) 152 patients in strict agreement with the diagnostic guidelines of the WHO including BM biopsy evaluation as major criterion. Both cohorts were compared and analyzed to regarding their presenting clinico-pathological data, driver mutation status, and follow-up. Diagnosis of post-ET myelofibrosis or progression into overt myelofibrosis with myeloid metaplasia was made according to previously published criteria.Results Following the BCSH criteria, 209 patients were diagnosed as ET. When reclassifying those cases according to the WHO criteria including BM morphology examination, 80 (38.3%) patients were diagnosed as prePMF and 14 (6.7%) as PV and two were diagnosed as PMF (0.9%). Comparison of clinical features of BCSH-ET and WHO-ET revealed significant differences in LDH levels and palpable splenomegaly at diagnosis. Fibrosis-free survival was significantly shorter in BCSH-ETs (Fig. 1A) as was overall survival (Fig. 1B). When reclassifying the BCSH cohort according to WHO criteria, progression-free and overall survival were significantly shorter in WHO-confirmed prePMF (Fig. 1C and 1D).Summary/Conclusion The striking differences in outcome are certainly linked with the entry of many prePMF cases in the BCSH-confirmed cohort. The inclusion of these cases, as well as cases with masked PV demonstrates, that BCSH criteria A1-3 may lead clinicians to refrain from performing BM biopsy in patients with elevated thrombocyte counts, which impairs accurate diagnosis with subsequent inadequate management and inferior prognosis. Our results highlight the central role of BM biopsy to achieve accurate diagnosis and differentiation of ET and prePMF. [Display omitted] DisclosuresGisslinger:Geron: Consultancy; AOP ORPHAN: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi Aventis: Consultancy; Novartis: Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen Cilag: Honoraria, Speakers Bureau.

Guidelines for the diagnosis and management of adult aplastic anaemia.

Sally B. Killick (Writing Group Chair), Nick Bown, Jamie Cavenagh, Inderjeet Dokal, Theodora Foukaneli, Peter Hillmen, Robin Ireland, Austin Kulasekararaj, Ghulam Mufti, John A Snowden, Sujith Samarasinghe, Anna Wood (BCSH Task Force Member), Judith C.W. Marsh on behalf of the British Society for Standards in Haematology. The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust, Bournemouth, Northern Genetics Service, Newcastle upon Tyne, St Bartholomew’s Hospital, Barts Health NHS Trust, London, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Barts Health NHS Trust, London, Addenbrooks Hospital, University of Cambridge, Cambridge, Leeds Teaching Hospitals, Leeds, Kings College Hospital NHS Foundation Trust, London, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield Great Ormond Street Hospital for Children NHS Foundation Trust, London, West Hertfordshire NHS Trust, Watford.

BCSH guideline for the use of anti-D immunoglobulin for the prevention of haemolytic disease of the fetus and newborn.

BCSH guideline for the use of anti-D immunoglobulin for the prevention of haemolytic disease of the fetus and newborn.

Guidelines on the management of anaemia and red cell transfusion in adult critically ill patients.

Forward This document aims to summarize the current literature guiding the use of red cell transfusion in critically ill patients and provides recommendations to support clinicians in their day-to-day practice. Critically ill patients differ in their age, diagnosis, co-morbidities, and severity of illness. These factors influence their tolerance of anaemia and alter the risk to benefit ratio of transfusion. The optimal management for an individual may not fall clearly within our recommendations and each decision requires a synthesis of the available evidence and the clinical judgment of the treating physician. This guideline relates to the use of red cells to manage anaemia during critical illness when major haemorrhage is not present. A previous British Committee for Standards in Haematology (BCSH) guideline has been published on massive haemorrhage (Stainsby et al, 2006), but this is a rapidly changing field. We recommend readers consult recent guidelines specifically addressing the management of major haemorrhage for evidence-based guidance. A subsequent BCSH guideline will specifically cover the use of plasma components in critically ill patients.

Guidelines for pre‐transfusion compatibility procedures in blood transfusion laboratories

Guidelines for pre‐transfusion compatibility procedures in blood transfusion laboratories

A re-audit of paediatric blood transfusions within a secondary care trust

<h3>Aim</h3> Paediatric blood transfusions have a significantly greater incidence of adverse outcomes in comparison with adults. In 2005, following a baseline audit, (presented at the RCPCH Annual Conference) we designed a local proforma incorporating the British Committee for Standards in Haematology (BCSH) guidelines on paediatric blood transfusion. Following an audit of this in 2007, education on blood transfusions was implemented. In 2010 the National Comparative Audit of the use of Red Cells in Neonates and Children made multiple new recommendations for safe paediatric blood transfusion. This is a re-audit comparing current practice with guidelines and the recommendations of the National Comparative Audit with the aim of improving the quality of care delivered to children receiving blood transfusion. <h3>Method</h3> A retrospective case notes audit was conducted on all general paediatric patients who received a packed red cell transfusion during a one year period (11/08/2010 to 11/08/2011). The local proforma for each transfusion was analysed. <h3>Results</h3> There were 52 blood transfusions (15 patients) within the time period, however 41 were available for analysis. 98% utilised the Trust proforma versus 91.5% in 2007. The salient results are represented in tabular and graphical form (table 1 and figure 1). <h3>Conclusions</h3> Safe transfusion practice with recording of observations on all patients was demonstrated. We have demonstrated improvement over six years, although there is still room for development in order to adhere to the National Comparative Audit recommendations and the 2004 BCSH guidelines. We have been closely monitoring transfusion practice for six years and there have been no adverse events. Having completed the audit cycle we are committed to vigilantly improving practice within this high risk area.

An audit of blood transfusion in palliative care

BackgroundIn a palliative care setting, to whom should we offer blood transfusion and when should we stop? Is there consensus regarding the best care for our patients? Transfusion should be...

Guidelines on oral anticoagulation with warfarin – fourth edition

Guidelines on oral anticoagulation with warfarin – fourth edition

Management of post‐transplant lymphoproliferative disorder in adult solid organ transplant recipients – BCSH and BTS Guidelines

A joint working group established by the Haemato-oncology subgroup of the British Committee for Standards in Haematology (BCSH) and the British Transplantation Society (BTS) has reviewed the available literature and made recommendations for the diagnosis and management of post-transplant lymphoproliferative disorder in adult recipients of solid organ transplants. This review details the therapeutic options recommended including reduction in immunosuppression (RIS), transplant organ resection, radiotherapy and chemotherapy. Effective therapy should be instituted before progressive disease results in declining performance status and multi-organ dysfunction. The goal of treatment should be a durable complete remission with retention of transplanted organ function with minimal toxicity.

Diagnosis of post‐transplant lymphoproliferative disorder in solid organ transplant recipients – BCSH and BTS Guidelines

A joint working group established by the Haemato-oncology subgroup of the British Committee for Standards in Haematology (BCSH) and the British Transplantation Society (BTS) has reviewed the available literature and made recommendations for the diagnosis and management of post-transplant lymphoproliferative disorder (PTLD) in adult recipients of solid organ transplants. This review details the risk factors predisposing to development, initial features and diagnosis. It is important that the risk of developing PTLD is considered when using post transplant immunosuppression and that the appropriate investigations are carried out when there are suspicions of the diagnosis. These must include tissue for histology and computed tomography scan to assess the extent of disease. These recommendations have been made primarily for adult patients, there have been some comments made with regard to paediatric practice.

Immune thrombocytopenic purpura in pregnancy

This review assesses the need for revision of the present guidelines for immune thrombocytopenic purpura in pregnancy based on evidence-based data from published articles of relevance. The American Society of Hematology (ASH) and British Committee for Standards in Haematology (BCSH) guidelines indicate that at platelet counts below 70,000 or 80,000/microl, respectively, causes of thrombocytopenia other than gestational thrombocytopenia should be considered. The ASH guidelines indicate that for severe thrombocytopenia or thrombocytopenic bleeding in the third trimester, intravenous immunoglobulin is an appropriate first-line agent. No consensus was reached concerning the use of intravenous immunoglobulin or corticosteroids as first-line therapy at other gestational periods. Splenectomy is considered acceptable for patients with refractory immune thrombocytopenic purpura and severe thrombocytopenia with bleeding only in the second trimester. Laparoscopic splenectomy can be safely performed during pregnancy. The BCSH guidelines are consistent with contemporary practice in recommending that the mode of delivery of a pregnant patient with immune thrombocytopenic purpura should be determined based on maternal indications. Screening of articles published since the formulation of the BCSH guidelines in 2003 did not reveal new data that would lead to significant revisions in the guidelines. Though outdated in some aspects, the ASH and BCSH guidelines still provide a useful framework for management of pregnant patients with immune thrombocytopenic purpura.

Justifying the clinical use of fresh frozen plasma - an audit.

To determine the appropriateness of fresh frozen plasma (FFP), uses in various haematological and clinical disorders, with reference to the British Committee for Standards in Haematology (BCSH) guidelines through an audit. Descriptive study. Department of Haematology and Transfusion Medicine, Shalamar Hospital, Lahore, from June 2001 to June 2004. The data was collected from June 2001 to June 2004 from the request forms ordered by the clinicians for the transfusion of FFP at the Department of Haematology and Transfusion Medicine, Shlamar Hospital, Lahore. A total of 2075 healthy blood donors donated their whole blood for the preparation of fresh frozen plasma (FFP). All blood donors were screened for anti HCV, HBsAg, VDRL and HIV. Those 2075 FFP units were prepared on high-speed centrifuge and were rapidly stored at -30oC freezer. A total of 587 patients were transfused 2075 units of FFP for various clinical disorders. The percentage of FFP units, transfused appropriately and inappropriately, as defined by BCSH guidelines, was estimated. Out of 2075 FFP units, 335 (24.41%) FFP units were transfused to patients suffering from bleeding due to disseminated intravascular coagulation (DIC), 306 (22.30%) units used for massive transfusion and surgical bleeding, 236 (17.20%) units for bleeding due to chronic liver disease, 202 (14.72%) units used to control bleeding due to coagulation factor deficiencies, 84(6.12%) units for thromobotic thrombocytopenic purpura (TTP), 75(5.46%) units prior to liver biopsy to correct prolonged prothrombin time (PT), 72(5.24%) units for haemorrhage due to haemolytic disease of newborn (HDN) and 62(4.51%) units to control bleeding due to warfarin overdosage, 425(60.45%) units used for nutritional support and hypovolaemia replacement, 131(18.63%) units for the reversal of prolonged INR in the absence of bleeding due to warfarin, 92 (13.08%) units used in ICU to correct prolonged PT without bleeding due to Vitamin K deficiency and 55(7.82%) units for chronic liver disease (CLD) to correct prolonged PT and APTT in the absence of bleeding. In summary, 1372 (66.12%) FFP units were appropriately and 703 (33. 88 %) were inappropriately used. In conclusion, 33.88% FFP was inappropriately used mainly due to lack of awareness of international guidelines and ignorance of risks.

P12 An Audit of Fresh Frozen Plasma Transfusion Use in the Royal Hospitals Trust (RGHT)

Allogeneic fresh frozen plasma (FFP) transfusions have increased in recent years, in the Royal Group of Hospitals Trust and in the UK as a whole. In the 2003 Serious Hazards of Transfusion report, FFP was the blood product most commonly attributed to the development of transfusion associated acute lung injury and a leading cause of transfusion related mortality. In the British Committee for Standards in Haematology (BCSH) guidelines there are few indications for FFP transfusion. Stainsby found that appropriateness of FFP transfusion in England varied from 62–92%.Audit objectives (i) To assess the appropriateness of FFP transfusions in the RGHT against BCSH guidelines ‐ 100% standard; and (ii) To assess the adequacy of documentation for FFP transfusion episodes re indication for transfusion and clinical effectiveness ‐ 100% standard.Method Data relating to FFP transfusion episodes between October 2004 and January 2005 inclusive, was extracted retrospectively from available patient notes by an SpR in haematology and a consultant anaesthetist. Anonymously completed proformas were jointly assessed for appropriateness of transfusion by the same investigators. FFP transfusion episodes Appropriate Inappropriate 137 episodes (114 patients) 93 (68%) 44 (32%) Reversal of warfarin effect, bleeding not severe or absent 16 Hepatic disease induced coagulopathy, no bleeding 6 Heparin/antiplatelet induced coagulopathy, with bleeding 4 Other causes of coagulopathy without bleeding 13 Ongoing blood loss, normal coagulation screen 4 Normal coagulation screen, no evidence of bleeding 1 Clinical documentation Present Absent Statement re indication for FFP transfusion 73 (53%) 64 (47%) Statement re clinical effectiveness of transfusion 52 (38%) 85 (62%) Conclusion and Recommendations A significant number of FFP transfusions are inappropriate, based on recent BCSH guidance. Documentation in clinical notes concerning the indication and response to FFP transfusion is frequently lacking. Appropriateness of FFP transfusion and associated clinical documentation should be improved by staff education and greater awareness of BCSH guidelines. Education should also include appropriate monitoring and management of bleeding secondary to warfarin or antiplatelet therapy. FFP transfusions should be re‐audited 1 year hence. Guidelines for the use of fresh‐frozen plasma, cryoprecipitate and cryosupernatant. The British Society for Haematology 2004, 126: 11–28 Stainsby D. Audit of the Appropriate Use of Fresh Frozen Plasma, National Blood Service, May 2002.

An audit of thrombophilia screens: results from the National Pathology Alliance benchmarking review

Aims: The National Pathology Alliance benchmarking review has completed six years of data collection and analysis of the workload and organisation of haematology laboratories in the UK. This study audits...

Response to van Veen et al

We note the retrospective report by van Veen et al on children with acute lymphoblastic leukaemia (ALL) with interest. When Task Forces of the British Committee for Standards in Haematology (BCSH) prepare guidelines for good practice, all available information is taken into account. It is accepted that the best evidence comes from randomized controlled clinical trials, but unfortunately there is often a dearth of such data in many areas of transfusion practice, for both children and adults. The Task Forces therefore have to refer to such information and studies as are available, which are mostly case reports and retrospective uncontrolled surveys. Among such reports is the account from Howard et al (2000), which evaluated 5223 lumbar punctures in 958 children with ALL at diagnosis and during treatment, and to which reference was made in the Guidelines for the Transfusion of Neonates and Older Children (BCSH, 2004). The relevant section in the BCSH Guidelines for the Transfusion of Neonates and Older Children (BCSH, 2004) (5.2.2. Platelets) includes the following statements (reference details are given in BCSH (2004): ‘In the absence of evidence-based guidelines for children, Table V reflects current recommended practice in children (Hume, 1996: level IIb evidence, grade B recommendation; Cahill & Lilleyman, 1998: level IV evidence, grade C recommendation; Ancliff & Machin, 1998: level IV evidence, grade C recommendation; Howard et al, 2000: level III evidence, grade B recommendation)…In children with aplasia, a restrictive policy with platelet transfusion is safe for long-term management (Sagmeister et al, 1999: level IV evidence, grade C recommendation). However, children with aplastic anaemia during and following treatment with ALG (antilymphocyte globulin) in particular may require intensive platelet support. In contrast, some paediatricians are prepared to conduct follow-up lumbar punctures on children with counts as low as 20 × 109/l, having not experienced unduly high adverse effects’. Table V of these Guidelines lists the indications for prophylactic platelet transfusion in children with thrombocytopenia as a result of reduced production (from any cause) and includes patients with a platelet count of 20–40 × 109/l prior to lumbar puncture (or central venous line insertion). It should be noted that this recommendation refers to a lumbar puncture performed in any setting. The BCSH Guidelines for the use of Platelet Transfusions (BCSH, 2003) state that there is a lack of evidence to guide decisions regarding platelet transfusions to cover invasive procedures, and that it is unlikely that comprehensive studies could be carried out because of the large number of variables involved. The BCSH guidelines indicate that work in this area is reviewed in the American Society of Clinical Oncology guidelines on platelet transfusion (Schiffer et al, 2001), including the papers by Edelson et al (1974) and Howard et al (2000). Schiffer et al (2001) pointed out that lumbar puncture is often more technically difficult in adults than in children, and that it is unclear whether the exemplary safety reported by Howard et al (2000) in children with ALL could be duplicated in adults. Guidance in the BCSH Guidelines for the use of Platelet Transfusions (BCSH, 2003) was given on the basis of this information and expert opinion, and included the recommendation that the platelet count should be raised to at least 50 × 109/l for lumbar puncture, epidural anaesthesia, gastroscopy and biopsy, insertion of indwelling lines, transbronchial biopsy, liver biopsy, laparotomy or similar procedures (grade B, level III). We do not demur from the advice from van Veen et al, given the specific circumstances affecting their patients, and we have acknowledged similar practice. We also acknowledge that transfusion of any blood component or product must be prescribed with the utmost care and consideration of long-term effects, especially in younger patients. Nevertheless, we do feel that the advice in the BCSH guidelines is founded on the best current information available.

Current performance of patient sample collection in the UK.

Collection of the patient sample for pretransfusion testing begins a complex chain of events in the transfusion process. Hospitals in England and North Wales were surveyed to compare local policies against recommendations of the British Committee for Standards in Haematology (BCSH). Hospitals also measured the frequency of rejected and miscollected samples [designated as wrong blood in tube (WBIT)]. 185 of 360 (51.4%) hospitals returned questionnaires and 182 of 185 (98%) hospitals reported that a policy for sample collection existed. Apart from frequent omission of the gender of the patient, there was 96% compliance with all mandatory identifiers of the BCSH guidelines. Practice allowing additions or changes to labelling on sample tubes and request forms varied. 3.2% (14 114/445 726) of samples submitted were rejected for various reasons, the most frequent being incomplete or missing information (49.5% of the total rejected samples). The corrected mean frequency for WBIT in the 27 hospitals with one or more observed WBIT was 1 in 1501 samples (95% CI: < or =1129.09 to < or =1872.91), and the median corrected frequency for WBIT was 1 in 1303 samples. This study has identified great variation in the policy and practice for sample collection for pretransfusion testing. Regular tracking of the rates of sample rejection and WBIT could be used to identify poor performance in individual hospitals requiring investigation and action.