Objective: The aim of this study was to identify a mortality benefit with the use of whole blood (WB) as part of the resuscitation of bleeding trauma patients. Background: Blood component therapy (BCT) is the current standard for resuscitating trauma patients, with WB emerging as the blood product of choice. We hypothesized that the use of WB versus BCT alone would result in decreased mortality. Methods: We performed a 14-center, prospective observational study of trauma patients who received WB versus BCT during their resuscitation. We applied a generalized linear mixed-effects model with a random effect and controlled for age, sex, mechanism of injury (MOI), and injury severity score. All patients who received blood as part of their initial resuscitation were included. Primary outcome was mortality and secondary outcomes included acute kidney injury, deep vein thrombosis/pulmonary embolism, pulmonary complications, and bleeding complications. Results: A total of 1623 [WB: 1180 (74%), BCT: 443(27%)] patients who sustained penetrating (53%) or blunt (47%) injury were included. Patients who received WB had a higher shock index (0.98 vs 0.83), more comorbidities, and more blunt MOI (all P<0.05). After controlling for center, age, sex, MOI, and injury severity score, we found no differences in the rates of acute kidney injury, deep vein thrombosis/pulmonary embolism or pulmonary complications. WB patients were 9% less likely to experience bleeding complications and were 48% less likely to die than BCT patients (P<0.0001). Conclusions: Compared with BCT, the use of WB was associated with a 48% reduction in mortality in trauma patients. Our study supports the use of WB use in the resuscitation of trauma patients.

The objectives of some experiments are to compare the variances of two or more treatments, products, or techniques. If the investigator is more concerned about within-unit variances rather than between-unit variances, then a repeated measurement design is needed. We invoke a random effects model with heterogeneous within-unit variances for certain repeated measurement designs. We do not impose any distributional assumptions for the random effects, whereas we assume either a normal or multivariate t distribution for the random errors. We propose a partial likelihood analysis for population-based inference and individual-based inference. We illustrate the methodology with an example from a trial comparing serum cholesterol measurements from a routine laboratory analyzer to those of a standardized method.

Objective: The association between renin-angiotensin-aldosterone (RAAS) inhibitors and Coronavirus diseases 2019 (COVID-19) mortality is unclear. We aimed to explore the association of RAAS inhibitors, including angiotensin-converting inhibitors (ACEi) and angiotensin II receptor blockers (ARBs) with COVID-19 mortality in patients with hypertension. Methods: MEDLINE, SCOPUS, OVID, and Cochrane Library were searched for the period of January 1, 2020 to May 20, 2020. Studies reporting the association of RAAS inhibitors (ACEi and ARBs) and mortality in patients with hypertension, hospitalized for COVID-19 were extracted. Two reviewers independently extracted appropriate data of interest and assessed the risk of bias. All analyses were performed using random-effects models on log-transformed risk ratio estimates, and heterogeneity was quantified. Results: Data were collected on 2,065,805 individuals (mean age, 58.73 years; 53.4% male). Patients with hypertension taking RAAS inhibitors were 35% less likely to die from COVID-19 compared to patients with hypertension not taking RAAS inhibitors (pooled RR= 0.65, 95% Confidence Intervals (CI): 0.45-0.94). To explore the association of COVID-19 and specific classes of RAAS inhibitors, we conducted a subgroup analysis of ARBs and ACEi separately from studies that provided them. Pooled risk ratio estimates from ARBs and ACEi showed a lower but not significant risk of death from COVID-19 (RR=0.93, 95% CI: 0.70-1.22) and ACEi (RR=0.65, 95% CI: 0.32-1.30). Conclusions: In this meta-analysis, it was discovered that taking RAAS inhibitors, significantly decreased the risk of COVID-19 mortality in patients with hypertension. This indicates a potential protective role that RAAS-inhibitors may have in COVID-19 patients with hypertension.