Oxford, United States
Oxford, United States

Time filter

Source Type

Lin Y.,University of Toronto | Stanworth S.,Oxford Radcliffe Hospitals Trust | Birchall J.,Haematology and Transfusion Medicine | Doree C.,Systematic Review Initiative | Hyde C.,University of Exeter
CMAJ | Year: 2011

Background: The benefits and risks of off- label use of recombinant factor VIIa in patients without hemophilia are contested. We performed a systematic review to assess the effectiveness and safety of such use. Methods: We searched electronic databases including MEDLINE, EMBASE and CENTRAL for randomized controlled trials comparing recombinant factor VIIa with placebo in any patient population except those with hemophilia up to January 2010. Eligible articles were assessed for inclusion, data were extracted, and study quality was evaluated. Outcomes included mortality, blood loss, requirements for red blood cell transfusion, number of patients transfused and thromboembolic events. Results: We identified 26 trials: 14 on off-label prophylactic use of recombinant factor VIIa (n = 1137) and 12 on off-label therapeutic use (n = 2538). In the studies on prophylactic use, we found no significant difference in mortality or thromboembolic events between the treatment and placebo groups. We found modest benefits favouring recombinant factor VIIa in blood loss (weighted mean difference -276 mL, 95% confidence interval [CI] -411 to -141 mL), red blood cell transfusion (weighted mean difference -281 mL, 95% CI -433 to -129 mL) and number of patients transfused (relative risk 0.71, 95% CI 0.50 to 0.99). In the therapeutic trials, we found a nonsignificant decrease in mortality and a nonsignificant increase in thromboembolic events but no difference in control of bleeding or red blood cell transfusion. Interpretation: Clinically significant benefits of recombinant factor VIIa as a general hemostatic agent in patients without hemophilia remain unproven. Given its potential risks, such use cannot be recommended, and in most cases, it should be restricted to clinical trials. © 2011 Canadian Medical Association or its licensors.

Smith G.A.,Barnet and Chase Farm Hospitals NHS Trust | Fisher S.A.,Systematic Review Initiative | Doree C.,Systematic Review Initiative | Roberts D.J.,Systematic Review Initiative | Roberts D.J.,John Radcliffe Hospital
Transfusion Medicine | Year: 2013

Background/Objectives: Blood donors attending a donation session may be deemed ineligible to donate blood due to a failure to meet low haemoglobin (Hb) thresholds. Several studies have identified factors associated with a donor falling below these Hb thresholds. A review of these factors will inform future prospective studies and form the basis for predictive models of deferral due to low Hb. Materials/Methods: Studies were identified by searching MEDLINE, EMBASE, The Cochrane Library and the WHO International Clinical Trials Registry from 1980 to September 2012. Demographic data, donor history, haematological/biological factors and the primary outcome of deferral due to low Hb were extracted. Analyses were descriptive and quantitative; pooled odds ratios (ORs) were obtained by meta-analysis. Results: Fifty-five studies met the inclusion criteria. A consistently higher rate of low Hb deferral was reported in females compared with males; meta-analysis showed a significantly greater risk of deferral due to low Hb in females compared with males in studies with universal Hb thresholds for males and females (OR 14·91, 95% confidence interval (CI) 12·82-17·34) and in studies with sex-specific Hb thresholds (OR 8·19, 95% CI 4·88-13·74). Greater rates of deferral due to low Hb were also associated with increasing age, higher ambient temperature, low body weight, shorter inter-donation interval and in donors of Hispanic or African descent. Conclusion: This work will help to define the criteria that should be considered in any large scale study of blood donor deferral, especially those that measure or aim to change failure to meet low Hb thresholds. © 2013 The Authors. Transfusion Medicine © 2013 British Blood Transfusion Society.

PubMed | Ottawa Health Research Institute, Systematic Review Initiative, University of Oxford, John Radcliffe Hospital and Haematology Transfusion Medicine
Type: | Journal: The Cochrane database of systematic reviews | Year: 2016

This is the protocol for a review and there is no abstract. The objectives are as follows: To determine whether different platelet transfusion thresholds for administration of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect the efficacy and safety of prophylactic platelet transfusions in preventing bleeding in patients with haematological disorders after chemotherapy with or without stem cell transplantation.

Jairath V.,Systematic Review Initiative
Cochrane database of systematic reviews (Online) | Year: 2010

BACKGROUND: Upper gastrointestinal haemorrhage affects 50 to 150 per 100,000 adults per year, with a high mortality. Red blood cell transfusions are frequently given, but their impact on rebleeding rates and mortality is unknown. OBJECTIVES: To assess the effects of red blood cell (RBC) transfusion in adults with upper gastrointestinal haemorrhage. SEARCH STRATEGY: For this update, we re-ran the initial search strategies from the last issue/month searched until March 2010.We previously searched the Cochrane Upper Gastrointestinal and Pancreatic Diseases Group Trials Register to February 2008, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 1), MEDLINE (1950 to February 2008), EMBASE (1974 to February 2008), the Systematic Review Initiative database of randomised controlled trials (RCTs), haematology and gastroenterology conference proceedings, and reference lists of articles. SELECTION CRITERIA: Randomised and quasi-randomised studies comparing RBC transfusion and standard care with other intravenous fluid and standard care regimens in haemodynamically stable and haemodynamically unstable adults with upper gastrointestinal haemorrhage. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. MAIN RESULTS: Three trials involving 126 patients were included, with complete data available for 93 patients. The participants were heterogeneous, none of the three studies examined exactly the same interventions or measured the same outcomes. Only two trials reported mortality data and the summary relative risk for mortality of the intervention was 5.4 (95% CI 0.27 to 107.09). One trial reported increased coagulation times in the transfused group, and reported these patients to have increased rates of rebleeding. None of the studies reported adverse events directly related to RBC transfusion. Methodological deficiencies, including allocation concealment, generation of random sequences and blinding, simply compound the uncertainty surrounding analysis. None of the studies were appropriately powered and in the largest study fewer than half the participants were included in the final analysis.One RCT of restrictive versus liberal RBC transfusion aims to recruit 860 patients but has yet to be completed. AUTHORS' CONCLUSIONS: There were more deaths and more rebleeding in the transfusion arms of the combined studies, but the small numbers of participants and large volume of missing data limit the significance of the findings. The studies in this review do not provide useful data regarding outcomes following red blood cell transfusion for acute upper gastrointestinal haemorrhage. They appear to exclude large survival benefit. Large, well-concealed RCTs of sufficient power are urgently needed.

PubMed | University of Cambridge, Systematic Review Initiative, Blood Supply and Blood Research Group
Type: Journal Article | Journal: Transfusion medicine (Oxford, England) | Year: 2016

Vasovagal reactions (VVRs) in blood donors have significant implications for the welfare of donors, donor retention and the management of donor sessions. We present a systematic review of interventions designed to prevent or reduce VVRs in blood donors. Electronic databases were searched for eligible randomised trials to March 2015. Data on study design and outcomes were extracted and pooled using random effects meta-analyses. Sixteen trials met the inclusion criteria: five trials (12 042 participants) of pre-donation water, eight trials (3500 participants) of applied muscle tension (AMT) and one trial each of AMT combined with water, caffeine, audio-visual distraction and/or social support. In donors receiving pre-donation water, the relative risk (RR) compared with controls for VVRs was 079 [95% confidence interval (CI) 070-089, P < 00001] and the mean difference (MD) in severity of VVRs measured with the Blood Donation Reactions Inventory (BDRI) score was -032 (95% CI -051 to -012, P < 00001). Excluding trials with a high risk of selection bias, the RR for VVRs was 070 (95% CI 045-111, P = 013). In donors who received AMT, there was no difference in the risk of chair recline in response to donor distress from controls (RR 076, 95% CI 053-110, P = 015), although the MD in BDRI score was -007 (95% CI -011 to -003, P = 00005). There was insufficient data to perform meta-analysis for other interventions. Current evidence on interventions to prevent or reduce VVRs in blood donors is indeed limited and does not provide strong support for the administration of pre-donation water or AMT during donation. Further large trials are required to reliably evaluate the effect of these and other interventions in the prevention of VVRs.

PubMed | National Health Research Institute, Systematic Review Initiative, University of Oxford and Haematology Transfusion Medicine
Type: Journal Article | Journal: The Cochrane database of systematic reviews | Year: 2016

This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the effects of different platelet transfusion thresholds prior to the insertion of a central line in patients with thrombocytopenia (low platelet count).

PubMed | Systematic Review Initiative, University of Oxford, Haematology Transfusion Medicine and Middlesex University
Type: Journal Article | Journal: The Cochrane database of systematic reviews | Year: 2016

This is the protocol for a review and there is no abstract. The objectives are as follows: To identify and assess the effectiveness of interventions to improve adherence to iron chelation therapy compared to standard care in people with SCD or thalassaemia including: identifying and assessing the effectiveness of different types of interventions (psychological and psychosocial, educational, medication interventions, or multi-component interventions);identifying and assessing the effectiveness of interventions specific to different age groups (children, adolescents, adults).

Hibbs S.P.,University of Oxford | Nielsen N.D.,University of Maryland Baltimore County | Brunskill S.,Systematic Review Initiative | Doree C.,Systematic Review Initiative | And 3 more authors.
Transfusion Medicine Reviews | Year: 2015

Decision support systems (DSSs) provide clinicians with tailored treatment recommendations by combining individual patient information and local guidelines. The objective of this systematic review was to assess the effects of electronic DSS on blood product ordering practices. Eligible studies were identified from searches of MEDLINE, Embase, CINAHL, The Cochrane Library, PubMed, and the Transfusion Evidence Library from January 2000 to April 2014. Of these, 23 articles were eligible, resulting in the inclusion of 20 independent studies in this systematic review. There was a significant variation in study population, the type of DSS used, and outcome reporting. All but one study used a before-after design without any element of randomization. Overall, there is good evidence that implementation of a DSS improves red blood cell usage. The effect of a DSS on plasma, platelets, and cryoprecipitate usage is less clear probably because fewer studies have been conducted focusing on these products. In addition, the introduction of a DSS resulted in cost savings in the 7 studies that reported financial outcomes. Patient outcomes were generally not studied in detail, and there were few data on the sustainability of the effect of DSS. Further data are needed to assess the effect of a DSS on blood products other than red blood cell, and future studies should standardize reporting of outcomes. © 2015 Elsevier Inc.

PubMed | University of Newcastle, University of Oxford, Systematic Review Initiative and Haematology Transfusion Medicine
Type: Journal Article | Journal: The Cochrane database of systematic reviews | Year: 2016

This is the protocol for a review and there is no abstract. The objectives are as follows: To compare a therapeutic-only versus prophylactic platelet transfusion policy for people with myelodysplasia, inherited or acquired aplastic anaemia, and other congenital bone marrow failure disorders.

PubMed | Systematic Review Initiative, University of Oxford and Weatherall Institute of Molecular Medicine
Type: Journal Article | Journal: Critical care (London, England) | Year: 2016

Anaemia affects 60-80% of patients admitted to intensive care units (ICUs). Allogeneic red blood cell (RBC) transfusions remain the mainstay of treatment for anaemia but are associated with risks and are costly. Our objective was to assess the efficacy and safety of iron supplementation by any route, in anaemic patients in adult ICUs.Electronic databases (CENTRAL, MEDLINE, EMBASE) were searched through March 2016 for randomized controlled trials (RCT)s comparing iron by any route with placebo/no iron. Primary outcomes were red blood cell transfusions and mean haemoglobin concentration. Secondary outcomes included mortality, infection, ICU and hospital length of stay, mean difference (MD) in iron biomarkers, health-related quality of life and adverse events.Five RCTs recruiting 665 patients met the inclusion criteria; intravenous iron was tested in four of the RCTs. There was no difference in allogeneic RBC transfusion requirements (relative risk 0.87, 95% confidence interval (CI) 0.70 to 1.07, p=0.18, five trials) or mean number of RBC units transfused(MD -0.45, 95 % CI -1.34 to 0.43, p = 0.32, two trials) in patients receiving or not receiving iron. Similarly, there was no difference between groups in haemoglobin at short-term (up to 10days) (MD -0.25, 95% CI -0.79 to 0.28, p=0.35, three trials) or mid-term follow up (last measured time point in hospital or end of trial) (MD 0.21, 95% CI -0.13 to 0.55, p=0.23, three trials). There was no difference in secondary outcomes of mortality, in-hospital infection, or length of stay. Risk of bias was generally low although three trials had high risk of attrition bias; only one trial had low risk of bias across all domains.Iron supplementation does not reduce RBC transfusion requirements in critically ill adults, but there is considerable heterogeneity between trials in study design, nature of interventions, and outcomes. Well-designed trials are needed to investigate the optimal iron dosing regimens and strategies to identify which patients are most likely to benefit from iron, together with patient-focused outcomes.PROSPERO International prospective register of systematic reviews CRD42015016627 . Registered 2 March 2015.

Loading Systematic Review Initiative collaborators
Loading Systematic Review Initiative collaborators