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1.  Effect of blood donor characteristics on transfusion outcomes: a protocol for systematic review and meta-analysis 
Systematic Reviews  2014;3:28.
Optimal selection of blood donors is of paramount importance in ensuring the safety of blood products. The current selection process is concerned principally with the safety of the blood donor and the safety of the patient that receives the blood. Recent evidence suggests that the characteristics of the donor may affect transfusion outcomes for the recipient.
We will conduct a systematic review of the association between major blood donor characteristics and red blood cell (RBC) transfusion outcomes. The primary objective is to assess the association of blood donor characteristics and the risk of adverse short-term and long-term clinical outcomes after RBC transfusion. We will search MEDLINE, EMBASE, Cochrane Central databases, as well as perform manual searches of top transfusion medical journals for prospective and retrospective studies. Study characteristics will be reported and the methodological quality of studies will be assessed. When appropriate, we will provide pooled odds ratio with 95% confidence intervals of the effect estimates, study clinical heterogeneity using pre-defined sensitivity and subgroup analyses, and study statistical heterogeneity using the I2 test.
The results of this systematic review will provide an evidence base regarding the potential clinical effects of donor characteristics on transfusion recipients to better guide policy and clinical practice. The evidence gathered from this review will also identify strengths and weaknesses of published studies regarding donor characteristics and transfusion outcomes and will identify knowledge gaps to inform future research in this field of transfusion medicine.
Trial registration
PROSPERO Registration Number: CRD42013006726
PMCID: PMC3998188  PMID: 24650633
2.  The Effect of Rituximab on Vaccine Responses in Patients with Immune Thrombocytopenia 
Blood  2013;122(11):1946-1953.
B-cell depletion therapy may impair vaccine responses and increase infection risk in patients with immune thrombocytopenia (ITP). Capitalizing on a multicenter randomized placebo-controlled trial, we investigated the effects of rituximab on the antibody and cellular responses to Streptococcus pneumoniae polysaccharide vaccine and Haemophilus influenzae type b (Hib) conjugate vaccine in ITP patients. Of 60 patients in the main trial, 24 patients received both vaccines 6 months after rituximab (n=17) or placebo (n=7). Among 20 evaluable patients, 3/14 (21%) in the rituximab group and 4/6 (67%) in the placebo group achieved a 4-fold increase in anti-pneumococcal antibodies (p=0.12). For anti-Hib antibodies, 4/14 (29%) and 5/6 (83%), respectively, achieved a 4-fold increase (p<0.05). Fewer patients in the rituximab group demonstrated functional Hib killing (2/14 [14%] versus 5/6 [83%], p<0.05). Three of 14 rituximab-treated patients failed to respond to vaccines by any criteria. After vaccinations, pre-plasma cell blasts and interferon-γ secreting T-cells were reduced in rituximab-treated patients. We found that antibody responses were impaired for at least 6 months after rituximab. Cellular immunity was reduced in parallel with the depleted B-cell pool. These findings have implications for the timing of vaccinations and the mechanism of infection after rituximab in patients with ITP.
PMCID: PMC3773242  PMID: 23851398 CAMSID: cams3208
3.  The Impact of Prolonged Storage of Red Blood Cells on Cancer Survival 
PLoS ONE  2013;8(7):e68820.
The duration of storage of transfused red blood cells (RBC) has been associated with poor clinical outcomes in some studies. We sought to establish whether prolonged storage of transfused RBC in cancer patients influences overall survival (OS) or cancer recurrence.
Methods and Findings
Patients diagnosed with cancer at The Ottawa Regional Cancer Centre between January 01, 2000 and December 31, 2005 were included (n = 27,591) where 1,929 (7.0%) received RBC transfusions within one year from diagnosis. Transfused RBC units were categorized as “new” if stored for less than 14 days, “intermediate” if stored between 14 and 28 days and “old” if stored for more than 28 days. Baseline characteristics between the comparative groups were compared by ANOVA test. Categorical variables and continuous variables were compared using Chi-squared and Wilcoxan rank-sum tests respectively. Overall survival was not associated with duration of storage of transfused RBC with a median survival of 1.2, 1.7, 1.1 years for only new, intermediate and old RBC units respectively (p = 0.36). Cancer recurrence was significantly higher in patients who received a RBC transfusion than those who did not (56.3% vs 33.0% respectively; p<0.0001) but was not affected by the duration of storage of transfused RBC (p = 0.06). In multivariate analysis, lung cancer, advanced stage, chemotherapy, radiation, cancer-related surgery and cancer recurrence were associated with inferior OS (p<0.05), while age, advanced stage, lung cancer, and more than 6 units of blood transfused were associated with cancer recurrence (p<0.05). The duration of storage of RBC before transfusion was not associated with OS or cancer recurrence in multivariate analysis.
In patients diagnosed with cancer, the duration of storage of transfused RBC had no impact on OS or cancer recurrence. This suggests that our current RBC storage policy of providing RBC of variable duration of storage for patients with malignancy is safe.
PMCID: PMC3712925  PMID: 23874777
4.  A cross-country comparison of intensive care physicians’ beliefs about their transfusion behaviour: A qualitative study using the theoretical domains framework 
Evidence of variations in red blood cell transfusion practices have been reported in a wide range of clinical settings. Parallel studies in Canada and the United Kingdom were designed to explore transfusion behaviour in intensive care physicians. The aim of this paper is three-fold: first, to explore beliefs that influence Canadian intensive care physicians’ transfusion behaviour; second, to systematically select relevant theories and models using the Theoretical Domains Framework (TDF) to inform a future predictive study; and third, to compare its results with the UK study.
Ten intensive care unit (ICU) physicians throughout Canada were interviewed. Physicians’ responses were coded into theoretical domains, and specific beliefs were generated for each response. Theoretical domains relevant to behaviour change were identified, and specific constructs from the relevant domains were used to select psychological theories. The results from Canada and the United Kingdom were compared.
Seven theoretical domains populated by 31 specific beliefs were identified as relevant to the target behaviour. The domains Beliefs about capabilities (confident to not transfuse if patients’ clinical condition is stable), Beliefs about consequences (positive beliefs of reducing infection and saving resources and negative beliefs about risking patients’ clinical outcome and potentially more work), Social influences (transfusion decision is influenced by team members and patients’ relatives), and Behavioural regulation (wide range of approaches to encourage restrictive transfusion) that were identified in the UK study were also relevant in the Canadian context. Three additional domains, Knowledge (it requires more evidence to support restrictive transfusion), Social/professional role and identity (conflicting beliefs about not adhering to guidelines, referring to evidence, believing restrictive transfusion as professional standard, and believing that guideline is important for other professionals), and Motivation and goals (opposing beliefs about the importance of restrictive transfusion and compatibility with other goals), were also identified in this study. Similar to the UK study, the Theory of Planned Behaviour, Social Cognitive Theory, Operant Learning Theory, Action Planning, and Knowledge-Attitude-Behaviour model were identified as potentially relevant theories and models for further study. Personal project analysis was added to the Canadian study to explore the Motivation and goals domain in further detail.
A wide range of beliefs was identified by the Canadian ICU physicians as likely to influence their transfusion behaviour. We were able to demonstrate similar though not identical results in a cross-country comparison. Designing targeted behaviour-change interventions based on unique beliefs identified by physicians from two countries are more likely to encourage restrictive transfusion in ICU physicians in respective countries. This needs to be tested in future prospective clinical trials.
PMCID: PMC3527303  PMID: 22999460
5.  The conundrum of persistent inappropriate use of frozen plasma 
Critical Care  2011;15(3):160.
Frozen plasma (FP) is commonly used for the treatment of bleeding or the prevention of bleeding in critically ill patients, but clinical evidence to help aid the critical care clinician make decisions on whether to transfuse or not is at present limited. Despite the limited evidence, it appears FP is administered not infrequently in the absence of bleeding or with no required procedure when the international normalized ratio (INR) is essentially normal (<1.5) or only mildly deranged (<2.5). The study by Stanworth and colleagues in a recent issue of Critical Care raises awareness of FP transfusion use in the critically ill, should prompt a consideration of curbing its use when it is not clearly appropriate, and illustrates the need for future high quality evidence to guide FP use in the critically ill when the risk:benefit ratio is less clear.
PMCID: PMC3218970  PMID: 21635704
6.  Appropriateness of the use of intravenous immune globulin before and after the introduction of a utilization control program 
Open Medicine  2012;6(1):e28-e34.
Intravenous immune globulin (IVIG) is an expensive and sometimes scarce blood product that carries some risk. It may often be used inappropriately. We evaluated the appropriateness of IVIG use before and after the introduction of an utilization control program to reduce inappropriate use.
We used the RAND/UCLA Appropriateness Method to measure the appropriateness of IVIG use in the province of British Columbia (BC) in 2001 and 2003, before and after the introduction of a utilization control program designed to reduce inappropriate use. For comparison, we measured the appropriateness of use during the same periods in the province of Alberta, which had no control program.
Of 2256 instances of IVIG use, 54.1% were deemed to be appropriate, 17.4% were of uncertain benefit, and 28.5% were deemed inappropriate. The frequency of inappropriate use in BC after the introduction of the utilization control program did not differ significantly from the frequency before the program or the frequency in Alberta.
Almost half of IVIG use in BC and Alberta was judged to be inappropriate or of uncertain benefit, and the frequency of inappropriate use did not decrease after implementation of a utilization control program in BC. More effective utilization controls are necessary to prevent wasted resources and unnecessary risk to patients.
PMCID: PMC3329117  PMID: 22567080
7.  Transfusion of red cells in hematopoietic stem cell transplantation (TRIST): study protocol for a randomized controlled trial 
Trials  2011;12:207.
Insight regarding transfusion practices in Hematopoietic Stem cell Transplantation (HSCT) are lacking and the impact of red cell transfusion in this high risk group on outcomes following HSCT are not well appreciated. Red blood cell transfusion can be life-saving, however, liberal use of transfusion in critically ill patients failed to demonstrate significant clinical benefit. A large number of other observational studies have also demonstrated an association between red blood cell transfusions and increased morbidity such as infections and multi organ failure as well as increased mortality. The role of red cell transfusion on the clinical outcomes observed in patients undergoing HSCT remains poorly understood and a prospective randomized study of transfusion is required to gain insight and knowledge on best transfusion practices in this high risk population.
This report describes the design and methodological issues of a randomized pilot study evaluating red cell transfusion triggers in the setting of Hematopoietic Stem Cell Transplantation. This study has been funded by a peer review grant from the Canadian Blood Services and is registered on NCT01237639.
In 3 Canadian centres, 100 patients undergoing Hematopoietic Stem Cell Transplantation will be randomized to either a restrictive (target hemoglobin of 70-90 g/L) or liberal (target hemoglobin of 90-110 g/L) red cell transfusion strategy, based daily hemoglobin values up to 100 days post-transplant. The study will stratify participants by centre and type of transplant. The primary goal is to demonstrate study feasibility and we will collect clinical outcomes on 1) Transfusion Requirements, 2) Transplant Related Mortality, 3) Maximum grade of acute Graft versus Host Disease, 4) Veno-occlusive Disease, 5) Serious Infections, 6) Bearman Toxicity Score, 7) Bleeding, 8) Quality of Life, 9) Number of Hospitalizations and 10) Number of Intensive Care Unit (ICU) Admissions.
Upon completion, this pilot trial will provide preliminary insight into red cell transfusion practice and its influence in hematopoietic stem cell transplant outcomes. The results of this trial will inform the conduct of a larger study.
PMCID: PMC3187728  PMID: 21936907
Hematopoietic Stem Cell Transplant; Red cell transfusion; Erythrocyte; Triggers; Randomized Clinical Trial; Pilot
8.  Using theories of behaviour to understand transfusion prescribing in three clinical contexts in two countries: Development work for an implementation trial 
Blood transfusion is an essential part of healthcare and can improve patient outcomes. However, like most therapies, it is also associated with significant clinical risks. In addition, there is some evidence of overuse. Understanding the potential barriers and enablers to reduced prescribing of blood products will facilitate the selection of intervention components likely to be effective, thereby reducing the number of costly trials evaluating different implementation strategies. Using a theoretical basis to understand behaviours targeted for change will contribute to a 'basic science' relating to determinants of professional behaviour and how these inform the selection of techniques for changing behaviour. However, it is not clear which theories of behaviour are relevant to clinicians' transfusing behaviour. The aim of this study is to use a theoretical domains framework to identify relevant theories, and to use these theories to identify factors that predict the decision to transfuse.
The study involves two steps: interview study and questionnaire study. Using a previously identified framework, we will conduct semi-structured interviews with clinicians to elicit their views about which factors are associated with waiting and further monitoring the patient rather than transfusing red blood cells. Interviews will cover the following theoretical domains: knowledge; skills; social/professional role and identity; beliefs about capabilities; beliefs about consequences; motivation and goals; memory, attention, and decision processes; environmental context and resources; social influences; emotion; behavioural regulation; nature of the behaviour. The interviews will take place independently in Canada and the UK and involve two groups of physicians in each country (UK: adult and neonatal intensive care physicians; Canada: intensive care physicians and orthopaedic surgeons). We will: analyse interview transcript content to select relevant theoretical domains; use consensus processes to map these domains on to theories of behaviour; develop questionnaires based on these theories; and mail them to each group of physicians in the two countries. From our previous work, it is likely that the theories will include: theory of planned behaviour, social cognitive theory and the evidence-based strategy, implementation intention. The questionnaire data will measure predictor variables (theoretical constructs) and outcome variables (intention and clinical decision), and will be analysed using multiple regression analysis. We aim to achieve 150 respondents in each of the four groups for each postal survey.
PMCID: PMC2777847  PMID: 19852832
9.  Continuous Multi-Parameter Heart Rate Variability Analysis Heralds Onset of Sepsis in Adults 
PLoS ONE  2009;4(8):e6642.
Early diagnosis of sepsis enables timely resuscitation and antibiotics and prevents subsequent morbidity and mortality. Clinical approaches relying on point-in-time analysis of vital signs or lab values are often insensitive, non-specific and late diagnostic markers of sepsis. Exploring otherwise hidden information within intervals-in-time, heart rate variability (HRV) has been documented to be both altered in the presence of sepsis, and correlated with its severity. We hypothesized that by continuously tracking individual patient HRV over time in patients as they develop sepsis, we would demonstrate reduced HRV in association with the onset of sepsis.
Methodology/Principal Findings
We monitored heart rate continuously in adult bone marrow transplant (BMT) patients (n = 21) beginning a day before their BMT and continuing until recovery or withdrawal (12±4 days). We characterized HRV continuously over time with a panel of time, frequency, complexity, and scale-invariant domain techniques. We defined baseline HRV as mean variability for the first 24 h of monitoring and studied individual and population average percentage change (from baseline) over time in diverse HRV metrics, in comparison with the time of clinical diagnosis and treatment of sepsis (defined as systemic inflammatory response syndrome along with clinically suspected infection requiring treatment). Of the 21 patients enrolled, 4 patients withdrew, leaving 17 patients who completed the study. Fourteen patients developed sepsis requiring antibiotic therapy, whereas 3 did not. On average, for 12 out of 14 infected patients, a significant (25%) reduction prior to the clinical diagnosis and treatment of sepsis was observed in standard deviation, root mean square successive difference, sample and multiscale entropy, fast Fourier transform, detrended fluctuation analysis, and wavelet variability metrics. For infected patients (n = 14), wavelet HRV demonstrated a 25% drop from baseline 35 h prior to sepsis on average. For 3 out of 3 non-infected patients, all measures, except root mean square successive difference and entropy, showed no significant reduction. Significant correlation was present amongst these HRV metrics for the entire population.
Continuous HRV monitoring is feasible in ambulatory patients, demonstrates significant HRV alteration in individual patients in association with, and prior to clinical diagnosis and treatment of sepsis, and merits further investigation as a means of providing early warning of sepsis.
PMCID: PMC2721415  PMID: 19680545
10.  Blood conservation strategies to reduce the need for red blood cell transfusion in critically ill patients 
Anemia commonly affects critically ill patients. The causes are multifactorial and include acute blood loss, blood loss from diagnostic testing and blunted red blood cell production. Blood transfusions are frequently given to patients in intensive care units to treat low hemoglobin levels due to either acute blood loss or subacute anemia associated with critical illness. Although blood transfusion is a life-saving therapy, evidence suggests that it may be associated with an increased risk of morbidity and mortality. A number of blood conservation strategies exist that may mitigate anemia in hospital patients and limit the need for transfusion. These strategies include the use of hemostatic agents, hemoglobin substitutes and blood salvage techniques, the reduction of blood loss associated with diagnostic testing, the use of erythropoietin and the use of restrictive blood transfusion triggers. Strategies to reduce blood loss associated with diagnostic testing and the use of hemostatic agents and erythropoietin result in higher hemoglobin levels, but they have not been shown to reduce the need for blood transfusions or to improve clinical outcomes. Lowering the hemoglobin threshold at which blood is transfused will reduce the need for transfusions and is not associated with increased morbidity or mortality among most critically ill patients without active cardiac disease. Further research is needed to determine the potential roles for other blood conservation strategies.
PMCID: PMC2151112  PMID: 18166731
11.  Does a perception of increased blood safety mean increased blood transfusion? An assessment of the risk compensation theory in Canada 
BMC Public Health  2004;4:20.
The risk compensation theory is a widely used concept in transport economics to analyze driver risk behaviour. This article explores the feasibility of applying the theory in blood transfusion to raise important questions regarding the increased blood safety measures and their possible effects on blood usage (e.g., the appropriateness in transfusion). Further, it presents the findings of a pilot survey of physicians in Canada.
While studies have attempted to define transfusion appropriateness, this article argues that if the risk compensation theory holds true for transfusion practice, physicians may actually be transfusing more. This may increase the possibility of contracting other unknown risks, such as the variant Creutzfeldt-Jakob Disease (vCJD), as well as increasing the risk of non-infectious transfusion risks, such as transfusion reactions.
A much larger study involving psychosocial assessment of physician decision making process to fully assess physician behaviour within the context of risk compensation theory and transfusion practice in Canada is needed to further explore this area.
PMCID: PMC425586  PMID: 15182381
12.  Risks of harms using antifibrinolytics in cardiac surgery: systematic review and network meta-analysis of randomised and observational studies 
Objective To estimate the relative risks of death, myocardial infarction, stroke, and renal failure or dysfunction between antifibrinolytics and no treatment following the suspension of aprotinin from the market in 2008 for safety reasons and its recent reintroduction in Europe and Canada.
Design Systematic review and network meta-analysis.
Data sources A Cochrane review of antifibrinolytic treatments was chosen as the starting point for this systematic review. Medline, Embase, and the Cochrane register of trials were searched with no date restrictions for observational evidence.
Study selection Propensity matched or adjusted observational studies with two or more of the interventions of interest (aprotinin, tranexamic acid, epsilon-aminocaproic acid, and no treatment) that were carried out in patients undergoing cardiac surgery.
Data analysis Network meta-analysis was used to compare treatments, and odds ratios with 95% credible intervals were estimated. Meta-analyses were carried out for randomised controlled trials alone and for randomised controlled trials with observational studies.
Results 106 randomised controlled trials and 11 observational studies (43 270 patients) were included. Based on the results from analysis of randomised controlled trials, tranexamic acid was associated on average with a reduced risk of death compared with aprotinin (odds ratio 0.64, 95% credible interval 0.41 to 0.99). When observational data were incorporated, comparisons showed an increased risk of mortality with aprotinin on average relative to tranexamic acid (odds ratio 0.71, 95% credible interval 0.50 to 0.98) and epsilon-aminocaproic acid (0.60, 0.43 to 0.87), and an increased risk of renal failure or dysfunction on average relative to all comparators: odds ratio 0.66 (95% credible interval 0.45 to 0.88) compared with no treatment, 0.66 (0.48 to 0.91) versus tranexamic acid, and 0.65 (0.45 to 0.88) versus epsilon-aminocaproic acid.
Conclusion Although meta-analyses of randomised controlled trials were largely inconclusive, inclusion of observational data suggest concerns remain about the safety of aprotinin. Tranexamic and epsilon-aminocaproic acid are effective alternatives that may be safer for patients.
PMCID: PMC3438881  PMID: 22968722

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