Abstract

BACKGROUND Recent work has shown that cluster-randomised trials can estimate two distinct estimands: the participant-average and cluster-average treatment effects. These can differ when participant outcomes or the treatment effect depends on the cluster size (termed informative cluster size). In this case, estimators that target one estimand (such as the analysis of unweighted cluster-level summaries, which targets the cluster-average effect) may be biased for the other. Furthermore, commonly used estimators such as mixed-effects models or generalised estimating equations with an exchangeable correlation structure can be biased for both estimands. However, there has been little empirical research into whether informative cluster size is likely to occur in practice. METHOD We re-analysed a cluster-randomised trial comparing two different thresholds for red blood cell transfusion in patients with acute upper gastrointestinal bleeding to explore whether estimates for the participant- and cluster-average effects differed, to provide empirical evidence for whether informative cluster size may be present. For each outcome, we first estimated a participant-average effect using independence estimating equations, which are unbiased under informative cluster size. We then compared this to two further methods: (1) a cluster-average effect estimated using either weighted independence estimating equations or unweighted cluster-level summaries, and (2) estimates from a mixed-effects model or generalised estimating equations with an exchangeable correlation structure. We then performed a small simulation study to evaluate whether observed differences between cluster- and participant-average estimates were likely to occur even if no informative cluster size was present. RESULTS For most outcomes, treatment effect estimates from different methods were similar. However, differences of >10% occurred between participant- and cluster-average estimates for 5 of 17 outcomes (29%). We also observed several notable differences between estimates from mixed-effects models or generalised estimating equations with an exchangeable correlation structure and those based on independence estimating equations. For example, for the EQ-5D VAS score, the independence estimating equation estimate of the participant-average difference was 4.15 (95% confidence interval: -3.37 to 11.66), compared with 2.84 (95% confidence interval: -7.37 to 13.04) for the cluster-average independence estimating equation estimate, and 3.23 (95% confidence interval: -6.70 to 13.16) from a mixed-effects model. Similarly, for thromboembolic/ischaemic events, the independence estimating equation estimate for the participant-average odds ratio was 0.43 (95% confidence interval: 0.07 to 2.48), compared with 0.33 (95% confidence interval: 0.06 to 1.77) from the cluster-average estimator. CONCLUSION In this re-analysis, we found that estimates from the various approaches could differ, which may be due to the presence of informative cluster size. Careful consideration of the estimand and the plausibility of assumptions underpinning each estimator can help ensure an appropriate analysis methods are used. Independence estimating equations and the analysis of cluster-level summaries (with appropriate weighting for each to correspond to either the participant-average or cluster-average treatment effect) are a desirable choice when informative cluster size is deemed possible, due to their unbiasedness in this setting.

Abstract

IMPORTANCE Intraventricular hemorrhage (IVH) is a major cause of neonatal morbidity and mortality in preterm infants without a specific medical treatment to date. OBJECTIVE To assess the safety and short-term outcomes of high-dose erythropoietin in preterm infants with IVH. DESIGN, SETTING, AND PARTICIPANTS Between April 1, 2014, and August 3, 2018, a randomized double-blind clinical trial enrolled 121 preterm infants (gestational age <32 weeks or birth weight <1500 g) aged 8 or less days with moderate to severe IVH identified by cerebral ultrasonography from 8 Swiss and Austrian tertiary neonatal units. Statistical analyses were performed between October 1, 2019, and September 12, 2022. INTERVENTIONS Infants received intravenous high-dose erythropoietin (2000 units/kg body weight) or placebo at 4 time points between weeks 1 and 4 of life. MAIN OUTCOMES AND MEASURES Secondary outcomes included (1) mortality and morbidity rates and (2) brain magnetic resonance imaging findings at term-equivalent age (TEA). The primary outcome was the composite intelligence quotient at 5 years of age (not available before 2023). RESULTS Sixty infants (48% male [n = 29]) were randomly assigned to receive erythropoietin, and 61 infants (61% male [n = 37]) were randomly assigned to receive placebo. The median birth weight was 832 g (IQR, 687-990 g) in the erythropoietin group and 870 g (IQR, 680-1110 g) in the placebo group. Median gestation was 26.1 weeks (IQR, 24.8-27.3 weeks) in the erythropoietin group and 27.0 weeks (24.9-28.1 weeks) in the placebo group. The 2 groups had similar baseline characteristics and morbidities. Up to TEA, 10 newborns died (16.7%) in the erythropoietin group, and 5 newborns (8.2%) died in the placebo group (adjusted odds ratio, 2.24 [95% CI, 0.74-7.66]; P = .15). Infants receiving erythropoietin had higher mean hematocrit levels. Conventional magnetic resonance imaging at TEA for 100 infants showed no significant differences in global or regional brain injury scores. CONCLUSIONS AND RELEVANCE This preliminary report of a randomized clinical trial found no evidence that high-dose erythropoietin in preterm infants with IVH affects brain injury scores on conventional magnetic resonance imaging at TEA. Higher mortality in the erythropoietin group was not significant but should be reassessed based on future results from similar trials. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02076373.

Abstract

BACKGROUND Anemia is a known risk factor for ischemic heart disease and serves as an independent predictor of major adverse cardiovascular events (MACE) in patients with acute coronary syndrome (ACS). This meta-analysis pools data from randomized controlled trials (RCTs) to better define hemoglobin (Hb) thresholds for transfusion in this setting. RESULTS MEDLINE, EMBASE, and Cochrane databases were searched using the terms "Acute Coronary Syndrome" AND "Blood Transfusion" including their synonyms. A total of three randomized controlled trials were included. Restrictive transfusion strategy (RTS) was defined as transfusing for Hb ≤ 8 g/dl with a post-transfusion goal of 8 to 10 g/dl. Liberal transfusion strategy (LTS) was defined as Hb ≤ 10 g/dl and post-transfusion goal of at least 11 g/dl. The primary end point was 30-day mortality. Secondary outcomes included recurrent ACS events, new or worsening CHF within 30 days, and major adverse cardiac events (MACE). The primary analytic method used was random effects model. Out of 821 patients, 400 were randomized to LTS, and 421 to RTS. Mean age was 70.3 years in RTS versus 76.4 in LTS. There was no statistically significant difference for 30-day mortality in LTS compared to RTS [odds ratio (OR) 1.69; 95% CI 0.35 to 8.05]. Similarly, there was no difference in MACE (OR 0.74; 95% CI 0.21 to 2.63), CHF (OR 0.82; 95% CI 0.18 to 3.76), or the incidence of recurrent ACS (OR 1.21; 95% CI 0.49 to 2.95). CONCLUSIONS In the setting of ACS, there is no difference between LTS and RTS for the outcomes of mortality, MACE, recurrent ACS, or CHF at 30 days. Further evidence in the form of high-quality RCTs are needed to compare RTS and LTS.

Abstract

PURPOSE To investigate the quantitative and qualitative efficacy of finger-prick autologous blood (FAB) eye drops versus conventional medical therapy for the treatment of severe dry eye disease (DED). METHODS Two centre, single masked, randomised controlled trial. Sixty patients in total were recruited with thirty patients (sixty eyes) treated with FAB eye drops four times per day in addition to their conventional DED treatment, and thirty patients (fifty-eight eyes) served as control subjects on conventional treatment alone. Ocular surface disease index (OSDI), Schirmer's test, fluorescein ocular staining grade (OCSG) Oxford schema and fluorescein tear film break-up time (TBUT), were performed at baseline, at 4 and 8 weeks. RESULTS OSDI scores significantly decreased in the FAB arm by greater than -17.68 (-37.67 to -2.96, p=0.02) compared to the control arm. There were greater improvements in OCSG and TBUT in the FAB arm but these were non-significant (p>0.05). CONCLUSION This feasibility study demonstrates adding FAB eye drops to conventional medical therapy for DED improves mean OSDI symptom score compared to conventional medical therapy alone. It may have particular use in settings where serum is unobtainable. An adequately powered and well-designed randomised trial is needed to further evaluate the long-term clinical benefit of FAB.

Abstract

BACKGROUND Erythrocyte transfusions are independently associated with acute kidney injury. Kidney injury may be consequent to the progressive hematologic changes that develop during storage. This study therefore tested the hypothesis that prolonged erythrocyte storage increases posttransfusion acute kidney injury. METHODS The Informing Fresh versus Old Red Cell Management (INFORM) trial randomized 31,497 patients to receive either the freshest or oldest available matching erythrocyte units and showed comparable mortality with both. This a priori substudy compared the incidence of posttransfusion acute kidney injury in the randomized groups. Acute kidney injury was defined by the creatinine component of the Kidney Disease: Improving Global Outcomes criteria. RESULTS The 14,461 patients included in this substudy received 40,077 erythrocyte units. For patients who received more than one unit, the mean age of the blood units was used as the exposure. The median of the mean age of blood units transfused per patient was 11 days [interquartile range, 8, 15] in the freshest available blood group and 23 days [interquartile range, 17, 30] in the oldest available blood group. In the primary analysis, posttransfusion acute kidney injury was observed in 688 of 4,777 (14.4%) patients given the freshest available blood and 1,487 of 9,684 (15.4%) patients given the oldest available blood, with an estimated relative risk (95% CI) of 0.94 (0.86 to 1.02; P = 0.132). The secondary analysis treated blood age as a continuous variable (defined as duration of storage in days), with an estimated relative risk (95% CI) of 1.00 (0.96 to 1.04; P = 0.978) for a 10-day increase in the mean age of erythrocyte units. CONCLUSIONS In a population of patients without severely impaired baseline renal function receiving fewer than 10 erythrocyte units, duration of blood storage had no effect on the incidence of posttransfusion acute kidney injury.

Abstract

Objective: Anemia is frequent in patients with acute myocardial infarction (AMI), and the optimal red blood cell transfusion strategy for AMI patients with anemia is still controversial. We aimed to compare the efficacy of restrictive and liberal red cell transfusion strategies in AMI patients with anemia. Methods: We systematically searched PubMed, EMBASE, Web of Science, Cochrane Library, and Clinicaltrials.gov, from their inception until March 2021. Studies designed to compare the efficacy between restrictive and liberal red blood cell transfusion strategies in patients with AMI were included. The primary outcome was all-cause mortality, including overall mortality, in-hospital or follow-up mortality. Risk ratios (RR) with 95% confidence intervals (CI) were presented and pooled by random-effects models. Results: The search yielded a total of 6,630 participants in six studies. A total of 2,008 patients received restrictive red blood cell transfusion while 4,622 patients were given liberal red blood cell transfusion. No difference was found in overall mortality and follow-up mortality between restrictive and liberal transfusion groups (RR = 1.07, 95% CI = 0.82-1.40, P = 0.62; RR = 0.89, 95% CI = 0.56-1.42, P = 0.62). However, restrictive transfusion tended to have a higher risk of in-hospital mortality compared with liberal transfusion (RR = 1.22, 95% CI = 1.00-1.50, P = 0.05). No secondary outcomes, including follow-up reinfarction, stroke, and acute heart failure, differed significantly between the two groups. In addition, subgroup analysis showed no differences in overall mortality between the two groups based on sample size and design. Conclusion: Restrictive and liberal red blood cell transfusion have a similar effect on overall mortality and follow-up mortality in AMI patients with anemia. However, restrictive transfusion tended to have a higher risk of in-hospital mortality compared with liberal transfusion. The findings suggest that transfusion strategy should be further evaluated in future studies.

Abstract

IMPORTANCE The optimal transfusion strategy in patients with acute myocardial infarction and anemia is unclear. OBJECTIVE To determine whether a restrictive transfusion strategy would be clinically noninferior to a liberal strategy. DESIGN, SETTING, AND PARTICIPANTS Open-label, noninferiority, randomized trial conducted in 35 hospitals in France and Spain including 668 patients with myocardial infarction and hemoglobin level between 7 and 10 g/dL. Enrollment could be considered at any time during the index admission for myocardial infarction. The first participant was enrolled in March 2016 and the last was enrolled in September 2019. The final 30-day follow-up was accrued in November 2019. INTERVENTIONS Patients were randomly assigned to undergo a restrictive (transfusion triggered by hemoglobin ≤8; n = 342) or a liberal (transfusion triggered by hemoglobin ≤10 g/dL; n = 324) transfusion strategy. MAIN OUTCOMES AND MEASURES The primary clinical outcome was major adverse cardiovascular events (MACE; composite of all-cause death, stroke, recurrent myocardial infarction, or emergency revascularization prompted by ischemia) at 30 days. Noninferiority required that the upper bound of the 1-sided 97.5% CI for the relative risk of the primary outcome be less than 1.25. The secondary outcomes included the individual components of the primary outcome. RESULTS Among 668 patients who were randomized, 666 patients (median [interquartile range] age, 77 [69-84] years; 281 [42.2%] women) completed the 30-day follow-up, including 342 in the restrictive transfusion group (122 [35.7%] received transfusion; 342 total units of packed red blood cells transfused) and 324 in the liberal transfusion group (323 [99.7%] received transfusion; 758 total units transfused). At 30 days, MACE occurred in 36 patients (11.0% [95% CI, 7.5%-14.6%]) in the restrictive group and in 45 patients (14.0% [95% CI, 10.0%-17.9%]) in the liberal group (difference, -3.0% [95% CI, -8.4% to 2.4%]). The relative risk of the primary outcome was 0.79 (1-sided 97.5% CI, 0.00-1.19), meeting the prespecified noninferiority criterion. In the restrictive vs liberal group, all-cause death occurred in 5.6% vs 7.7% of patients, recurrent myocardial infarction occurred in 2.1% vs 3.1%, emergency revascularization prompted by ischemia occurred in 1.5% vs 1.9%, and nonfatal ischemic stroke occurred in 0.6% of patients in both groups. CONCLUSIONS AND RELEVANCE Among patients with acute myocardial infarction and anemia, a restrictive compared with a liberal transfusion strategy resulted in a noninferior rate of MACE after 30 days. However, the CI included what may be a clinically important harm. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02648113.

Abstract

BACKGROUND Autologous whole blood (AWB) is used in complementary medicine for the treatment of infections and skin disorders. So far, the efficacy of AWB is discussed controversially. METHODS To estimate the efficacy of AWB therapy and to gather evidence in regard to effector mechanisms, we effected a systematic review of articles accessible through Pubmed and Cambase. Further trials were identified through references and by contacting study authors. Prospective controlled trials concerning intramuscular AWB therapy were included with the exception of trials using oxygenated, UV radiated or heated blood. Information was extracted on the indication, design, additions to AWB and outcome. Full texts were screened for information about the effector mechanisms. RESULTS Eight trials suited our criteria. In three controlled trials about atopic dermatitis and urticaria, AWB therapy showed beneficial effects. In five randomized controlled trials (RCTs), two of which concerned respiratory tract infections, two urticaria and one ankylosing spondylitis, no efficacy could be found. A quantitative assessment was not possible due to the heterogeneity of the included studies. We only found four controlled trials with sample sizes bigger than 37 individuals per group. Only one study investigated the effector mechanisms of AWB. CONCLUSIONS There is some evidence for efficacy of AWB therapy in urticaria patients and patients with atopic eczema. Firm conclusions can, however, not be drawn. We see a great need for further RCTs with adequate sample sizes and for investigation of the effector mechanisms of AWB therapy.

Abstract

Stroke is a major cause of death and long-term disability, affecting one in six people worldwide. The only currently available approved pharmacological treatment for ischemic stroke is tissue plasminogen activator; however, relatively few patients are eligible for this therapy. We hypothesized that intravenous (IV) infusion of banked unrelated allogeneic umbilical cord blood (UCB) would improve functional outcomes in patients with ischemic stroke. To investigate this, we conducted a phase 1 open-label trial to assess the safety and feasibility of a single IV infusion of non-human leukocyte antigen (HLA) matched, ABO matched, unrelated allogeneic UCB into adult stroke patients. Ten participants with acute middle cerebral artery ischemic stroke were enrolled. UCB units were matched for blood group antigens and race but not HLA, and infused 3-9 days post-stroke. The adverse event (AE) profile over a 12 month postinfusion period indicated that the treatment was well-tolerated in these stroke patients, with no serious AEs directly related to the study product. Study participants were also assessed using neurological and functional evaluations, including the modified Rankin Score (mRS) and National Institute of Health Stroke Scale (NIHSS). At 3 months post-treatment, all participants had improved by at least one grade in mRS (mean 2.8 +/- 0.9) and by at least 4 points in NIHSS (mean 5.9 +/- 1.4), relative to baseline. Together, these data suggest that a single i.v. dose of allogeneic non-HLA matched human UCB cells is safe in adults with ischemic stroke, and support the conduct of a randomized, placebo-controlled phase 2 study. Stem Cells Translational Medicine 2018.

Abstract

BACKGROUND Red blood cell transfusion remains controversial in patients with acute coronary syndromes and particularly in patients with ST-elevation myocardial infarction (STEMI). METHODS We systematically searched PubMed, Cochrane, EMBASE, and Web of Science for studies published until January 2017 describing the outcomes in patients with STEMI who received red blood cell transfusion, compared with patients who did not. RESULTS A total of 21,770 patients with STEMI from 5 cohort studies were included in the meta-analysis, 984 (4.5%) received red blood cell transfusion and 20,786 (95.4%) did not. Red blood cell transfusion was associated with a higher risk of in-hospital and long-term mortality, emergency repeated percutaneous coronary intervention (PCI), reinfarction rate, stroke rate, and heart failure. The group with red blood cell transfusion had a slightly higher incidence of diabetes mellitus and hypertension, but a lower incidence of smoking. The two groups had the same incidence of prior myocardial infarction, prior coronary artery bypass graft surgery and malignancy. Prior heart failure, prior stroke and prior PCI were more frequent in the group that had received red blood cell transfusion. The mean nadir haemoglobin was 8.5+/- 0.1g/dl in the group with red blood cell transfusion and 12.5+/- 0.4g/dl in the control group, p< 0.001. CONCLUSIONS Red blood cell transfusion increases the morbidity and mortality in patients with STEMI. This difference could not be explained by the higher morbidity in the red blood cell transfusion group alone. Further randomised controlled trials are required to provide a reliable haemoglobin threshold for these patients.