Background: In August 2017, Canadian Blood Services extended the shelf-life of platelet concentrates from 5 to 7 days. The clinical impacts of this policy change remain unclear.Study Design and Methods: We used a before-after retrospective design of platelet-transfused adult inpatients in Hamilton, ON, Canada. Data were captured for 18 months before (Period 1: February 2016-July 2017) and 18 months after (Period 2: September 2017-February 2019) 7-day platelet implementation.Primary outcome was absolute platelet count increment (ACI) in univariate and multivariate analyses adjusted for confounders. Data were obtained from our institution's transfusion database, Ontario's Transfusion Transmitted Injuries Surveillance System, and the blood supplier. Results: Overall, 1360 patients with single dose platelet transfusions were included in Period 1 and 1211 patients in Period 2. Median age at admission was 66 years, and approximately 40% of patients underwent cardiac surgery. Using a non-inferiority margin of À10 Â 10 9 /L, platelets transfused during the 7-day storage period were non-inferior to those transfused in the 5-day storage period [mean count difference À 4.63 Â 10 9 /L (95% CI À7.40 to À1.87, p = 0.0001)].However, platelet ACIs following transfusion consistently trended lower in the 7-day group for all patients and subgroups. No differences in secondary clinical outcomes were observed. Platelet expiry reduced from 8.1 to 6.3% (p < 0.0001). Conclusion:Platelet transfusions following 7-day storage policy were noninferior to transfusions in the 5-day policy period, although reduced ACIs were observed. There were no increases in adverse clinical outcomes.Platelets are a valuable, life-saving blood product transfused to prevent or treat bleeding. The duration of storage of platelets varies across countries. Some countries employ a short storage time, with a platelet shelf life of

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Background Immune thrombocytopenia (ITP) is a diagnosis of exclusion that can resemble other thrombocytopenic disorders. Objectives To develop a clinical prediction model (CPM) for the diagnosis of ITP to aid hematogists in investigating patients presenting with undifferentiated thrombocytopenia. Methods We designed a CPM for ITP diagnosis at the time of the initial hematology consultation using penalized logistic regression based on data from patients with thrombocytopenia enrolled in the McMaster ITP registry (n = 523) called the Predict‐ITP Tool. The case definition for ITP was a platelet count less than 100 × 109/L and a platelet count response after high‐dose corticosteroids or intravenous immune globulin, defined as the achievement of a platelet count above 50 × 109/L and at least a doubling of baseline. Internal validation was done using bootstrap resampling. Model discrimination was assessed by the c‐statistic, and calibration was assessed by the calibration slope, calibration‐in‐the‐large, and calibration plot. Results The final model included the following variables: (1) platelet count variability (based on three or more platelet count values), (2) lowest platelet count value, (3) maximum mean platelet volume, and (4) history of major bleeding (defined by the ITP bleeding scale). The optimism‐corrected c‐statistic was 0.83, the calibration slope was 0.88, and calibration‐in‐the‐large for all performance measures was <0.001 with standard error <0.001, indicating good discrimination and excellent calibration. Conclusions The Predict‐ITP Tool can estimate the likelihood of ITP for a given patient with thrombocytopenia at the time of the initial hematology consultation. The tool had high predictive accuracy for the diagnosis of ITP.

Background: At the start of the coronavirus disease 2019 (COVID-19) pandemic, widespread blood shortages were anticipated. We sought to Abbreviations: COVID-19, coronavirus disease 2019; PLT, platelet; RBC, red blood cell; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; WHO, World Health Organization; US, United States.

Background Equitable allocation of scarce blood products needed for a randomized controlled trial (RCT) is a complex decision‐making process within the blood supply chain. Strategies to improve resource allocation in this setting are lacking. Methods We designed a custom‐made, computerized system to manage the inventory and allocation of COVID‐19 convalescent plasma (CCP) in a multi‐site RCT, CONCOR‐1. A hub‐and‐spoke distribution model enabled real‐time inventory monitoring and assignment for randomization. A live CCP inventory system using REDCap was programmed for spoke sites to reserve, assign, and order CCP from hospital hubs. A data‐driven mixed‐integer programming model with supply and demand forecasting was developed to guide the equitable allocation of CCP at hubs across Canada (excluding Québec). Results 18/38 hospital study sites were hubs with a median of 2 spoke sites per hub. A total of 394.5 500‐ml doses of CCP were distributed; 349.5 (88.6%) doses were transfused; 9.5 (2.4%) were wasted due to mechanical damage sustained to the blood bags; 35.5 (9.0%) were unused at the end of the trial. Due to supply shortages, 53/394.5 (13.4%) doses were imported from Héma‐Québec to Canadian Blood Services (CBS), and 125 (31.7%) were transferred between CBS regional distribution centers to meet demand. 137/349.5 (39.2%) and 212.5 (60.8%) doses were transfused at hubs and spoke sites, respectively. The mean percentages of total unmet demand were similar across the hubs, indicating equitable allocation, using our model. Conclusion Computerized tools can provide efficient and immediate solutions for equitable allocation decisions of scarce blood products in RCTs.

Background Anti‐K is an alloantibody stimulated in response to the KEL1 antigen and may cause hemolytic disease of the fetus and newborn (HDFN). Provision of KEL1 negative blood to females of child‐bearing potential was not our practice. We assessed the impact of our policy and assessed feasibility of a KEL1 negative transfusion policy. Study design and methods This is a cohort study spanning Jan 1, 2007–Jun 30, 2017 in Hamilton, Canada. Data were obtained via our institution's transfusion database. Chart reviews of females age ≤45 with anti‐K were performed; data on RBC KEL1 phenotype were obtained from the blood supplier when needed to ascertain the cause of alloimmunization. Descriptive analysis of hospital KEL1 negative inventory demand and supply was performed. Results From Jan 2007‐Jun 2017, 8.6% of all RBC units transfused were provided to females age ≤45. There were 111 females with detectable anti‐K. Median age at time of antibody detection was 34 years (interquartile range 27–40) and 28 of 111 (25.2%) patients may have been alloimmunized by transfusion. Of 49 pregnancies, seven had complications due to anti‐K. We estimated that our existing RBC inventory (with 16% units known to be KEL1 negative in 2017) is sufficient to meet demand and support a KEL1 negative transfusion policy for females age ≤45. Conclusion Transfusion was responsible for alloimmunization in 25% of females with anti‐K over 10 years. Analysis of supply and demand can be used to inform feasibility of a KEL1 negative transfusion policy.

Background The Perioperative Anticoagulation Use for Surgery Evaluation study prospectively evaluated a prespecified periprocedural interruption strategy of direct oral anticoagulants (DOACs) among patients with atrial fibrillation. Coagulation testing is widely available and frequently requested prior to invasive procedures. Coagulation assays display poor sensitivity to clinically relevant DOAC concentrations. Objectives Determine the utility of routinely available coagulation testing at predicting a DOAC concentration of <30 ng/ml among patients in the preprocedural setting. Methods We calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive and negative likelihood ratio (LR+ and LR−) of a normal coagulation assay result for identifying patients with a preprocedural DOAC level < 30 ng/ml. Results We identified weak or very weak correlations between coagulation assay results and DOAC levels in the preprocedural setting, except for a moderate correlation between the thrombin time (TT) and dabigatran concentrations (ρ = 0.68; p < .001). The prothrombin time (PT) and activated partial thromboplastin time (APTT) demonstrated modest sensitivity (78.9% to 88.2%) and PPVs (76.4% to 93.1%) but poor specificity (13.2% to 53.3%) and NPVs (16.3% to 30.2%) across all three DOACs. A normal TT was associated with 100% specificity and PPV values for a dabigatran level < 30 ng/ml. A normal APTT among patients on dabigatran was associated with an LR+ of 1.671 (95% confidence interval [CI] 1.297, 2.154) and an LR− of 0.395 (95% CI 0.207, 0.751) for levels <30 ng/ml. Conclusions The PT and APTT perform poorly at safely identifying patients with negligible DOAC levels in the preprocedural setting.