Pre-specification of statistical analysis approaches in published clinical trial protocols was inadequate

OBJECTIVES: Results from randomized trials can depend on the statistical analysis approach used. It is important to prespecify the analysis approach in the trial protocol to avoid selective reporting of analyses based on those which provide the most favourable results. We undertook a review of published trial protocols to assess how often the statistical analysis of the primary outcome was adequately prespecified. METHODS: We searched protocols of randomized trials indexed in PubMed in November 2016. We identified whether the following aspects of the statistical analysis approach for the primary outcome were adequately prespecified: (1) analysis population; (2) analysis model; (3) use of covariates; and (4) method of handling missing data. RESULTS: e identified 99 eligible protocols. Very few protocols adequately prespecified the analysis population (8/99, 8%), analysis model (27/99, 27%), covariates (40/99, 40%), or approach to handling missing data (10/99, 10%). Most protocols did not adequately predefine any of these four aspects of their statistical analysis approach (39%) or predefined only one aspect (36%). No protocols adequately predefined all four aspects of the analysis. CONCLUSION: The statistical analysis approach is rarely prespecified in published trial protocols. This may allow selective reporting of results based on different analyses

ETHICAL: Ethnic Disparities In COVID-19 Admissions in east London

This study aims to assess whether there is a difference in age and sex adjusted outcomes in different ethnicities of patients with confirmed COVID 19 admitted to Barts Health. The study will test the hypothesis that there is an association between health outcomes; in terms of need for ITU admission and mortality; and ethnicity in COVID-19 positive patients admitted to Barts Health; with patients of Black, Asian and other Minority Ethnicities having poorer outcomes as compared to patients of White ethnicity

Critical care admission following elective surgery was not associated with survival benefit: prospective analysis of data from 27 countries

PURPOSE: As global initiatives increase patient access to surgical treatments, there is a need to define optimal levels of perioperative care. Our aim was to describe the relationship between the provision and use of critical care resources and postoperative mortality. METHODS: Planned analysis of data collected during an international 7-day cohort study of adults undergoing elective in-patient surgery. We used risk-adjusted mixed-effects logistic regression models to evaluate the association between admission to critical care immediately after surgery and in-hospital mortality. We evaluated hospital-level associations between mortality and critical care admission immediately after surgery, critical care admission to treat life-threatening complications, and hospital provision of critical care beds. We evaluated the effect of national income using interaction tests. RESULTS: 44,814 patients from 474 hospitals in 27 countries were available for analysis. Death was more frequent amongst patients admitted directly to critical care after surgery (critical care: 103/4317 patients [2%], standard ward: 99/39,566 patients [0.3%]; adjusted OR 3.01 [2.10–5.21]; p < 0.001). This association may differ with national income (high income countries OR 2.50 vs. low and middle income countries OR 4.68; p = 0.07). At hospital level, there was no association between mortality and critical care admission directly after surgery (p = 0.26), critical care admission to treat complications (p = 0.33), or provision of critical care beds (p = 0.70). Findings of the hospital-level analyses were not affected by national income status. A sensitivity analysis including only high-risk patients yielded similar findings. CONCLUSIONS: We did not identify any survival benefit from critical care admission following surgery

Prevalence of diabetic retinopathy in Indigenous and non-Indigenous Australians: a systematic review and meta-analysis

TOPIC: This systematic review and meta-analysis summarises evidence relating to the prevalence of diabetic retinopathy (DR) among Indigenous and non-Indigenous Australians. CLINICAL RELEVANCE: Indigenous Australians suffer disproportionately from diabetes-related complications. Exploring ethnic variation in disease is important for equitable distribution of resources and may lead to identification of ethnic-specific modifiable risk factors. Existing DR prevalence studies comparing Indigenous and non-Indigenous Australians have shown conflicting results. METHODS: This study was conducted following Joanna Briggs Institute guidance on systematic reviews of prevalence studies (PROSPERO ID: CRD42022259048). We performed searches of Medline (Ovid), EMBASE, and Web of Science until October 2021, using a strategy designed by an information specialist. We included studies reporting DR prevalence among diabetic patients in Indigenous and non-Indigenous Australian populations. Two independent reviewers performed quality assessments using a 9-item appraisal tool. Meta-analysis and meta-regression were performed using double arcsine transformation and a random-effects model comparing Indigenous and non-Indigenous subgroups. RESULTS: Fifteen studies with 8219 participants met criteria for inclusion. The Indigenous subgroup scored lower on the appraisal tool compared to the non-Indigenous subgroup (mean score 50% vs 72%, p=0.04). In the unadjusted meta-analysis, DR prevalence in the Indigenous subgroup (30.2% [95%CI: 24.9-25.7]) did not differ significantly (p=0.17) from the non-Indigenous subgroup (23.7% (95%CI: 16.8-31.4]). After adjusting for age and for quality, DR prevalence was higher in the Indigenous subgroup (p-values<0.01), with prevalence ratio point estimates ranging between 1.72-2.58, depending on the meta-regression model. For the secondary outcomes, prevalence estimates were higher in the Indigenous subgroup for diabetic macular oedema (8.7% vs 2.7%, p=0.02) and vision-threatening DR (8.6% vs 3.0%, p=0.03), but not for proliferative DR (2.5% vs 0.8%, p=0.07). CONCLUSION: Indigenous studies scored lower for methodological quality, raising the possibility that systematic differences in research practices may be leading to underestimation of disease burden. After adjusting for age and for quality, we found a higher DR prevalence in the Indigenous subgroup. This contrasts with a previous review which reported the opposite finding of lower DR prevalence using unadjusted pooled estimates. Future epidemiological work exploring DR burden in Indigenous communities should aim to address methodological weaknesses identified by this review

Plasma plume effects on the conductivity of amorphous-LaAlO₃/SrTiO₃ interfaces grown by pulsed laser deposition in O₂ and Ar

Amorphous LaAlO3/SrTiO3 interfaces exhibit metallic conductivity similarto those found for the extensively studied crystalline-LaAlO3/SrTiO3 interfaces. Here, we investigate the conductivity of the amorphous-LaAlO3/SrTiO3 interfaces grown in different pressures of O2 and Ar background gases. During the deposition, the LaAlO3 ablation plume is also studied, in situ, by fast photography and space-resolved optical emission spectroscopy. An interesting correlation between interfacial conductivity and kinetic energy of the Al atoms in the plume is observed: to assure conducting interfaces of amorphous-LaAlO3/SrTiO3, the kinetic energy of Al should be higher than 1 eV. Our findings add further insights on mechanisms leading to interfacial conductivity in SrTiO3-based oxide heterostructures

CT methods for measuring glenoid bone loss are inaccurate, and not reproducible or interchangeable.

AIMS: Glenoid bone loss is a significant problem in the management of shoulder instability. The threshold at which the bone loss is considered "critical" requiring bony reconstruction has steadily dropped and is now approximately 15%. This necessitates accurate measurement in order that the correct operation is performed. CT scanning is the most commonly used modality and there are a number of techniques described to measure the bone loss however few have been validated. The aim of this study was to assess the accuracy of the most commonly used techniques for measuring glenoid bone loss on CT. METHODS: Anatomically accurate models with known glenoid diameter and degree of bone loss were used to determine the mathematical and statistical accuracy of six of the most commonly described techniques (relative diameter, linear ipsilateral circle of best fit (COBF), linear contralateral COBF, Pico, Sugaya, and circle line methods). The models were prepared at 13.8%, 17.6%, and 22.9% bone loss. Sequential CT scans were taken and randomized. Blinded reviewers made repeated measurements using the different techniques with a threshold for theoretical bone grafting set at 15%. RESULTS: At 13.8%, only the Pico technique measured under the threshold. At 17.6% and 22.9% bone loss all techniques measured above the threshold. The Pico technique was 97.1% accurate, but had a high false-negative rate and poor sensitivity underestimating the need for grafting. The Sugaya technique had 100% specificity but 25% of the measurements were incorrectly above the threshold. A contralateral COBF underestimates the area by 16% and the diameter by 5 to 7%. CONCLUSION: No one method stands out as being truly accurate and clinicians need to be aware of the limitations of their chosen technique. They are not interchangeable, and caution must be used when reading the literature as comparisons are not reliable

Perioperative blood transfusion is associated with a gene transcription profile characteristic of immunosuppression: a prospective cohort study

INTRODUCTION Blood transfusion in the perioperative period has frequently been associated with an excess of nosocomial infections. Whilst transfused whole blood induces specific host immune alteration that may predispose to nosocomial infections, the immunomodulating properties associated with leukodepleted blood remain incompletely understood. In this study, we explore the hypothesis that the transfusion of leukodepleted allogeneic blood during or following major gastrointestinal surgery is associated with an immunosuppressed phenotype, which may in turn predispose to postoperative infectious complications. METHODS Patients aged over 45 years undergoing scheduled inpatient major gastrointestinal surgery were recruited. Gene expression profiles of specific inflammatory genes were assayed from blood collected preoperatively, at 24 and at 48 hours after surgery. Genes were selected based on their ability to represent specific immune pathways. Gene expression was quantified using quantitative real-time polymerase chain reaction (qRT-PCR) to measure messenger RNA (mRNA) levels. Postoperative infections were documented using predefined criteria. RESULTS One hundred and nineteen patients were recruited. Fifteen (13%) patients required blood transfusion within 24 hours of surgery, 44 (37%) patients developed infections and 3 (2%) patients died prior to discharge. Patients receiving a blood transfusion were more likely to develop postoperative infections (P =0.02) and to have lower tumour necrosis factor alpha (TNFα), interleukin (IL)-12, IL-23 and RAR-related orphan receptor gamma T (RORγt) gene expression in the postoperative period (P <0.05). The TNFα/IL-10 mRNA ratio at 24 hours (P =0.0006) and at 48 hours (P =0.01) was lower in patients receiving a blood transfusion over this period. Multivariable analysis confirmed that these observations were independent of the severity of the surgical insult. CONCLUSIONS An association between an immunosuppressive pattern of gene expression and blood transfusion following major elective gastrointestinal surgery is described. This gene expression profile includes a reduction in the activity of innate immunity and T helper cell type 1 (Th1) and T helper cell type 17 (Th17) pathways in those patients receiving a blood transfusion. Blood transfusion was also associated with an excess of infectious complications in this cohort. A mechanistic link is suggested but not proven

Frequency and distribution of rare electrophoretic mobility variants in a population of human newborns in Ann Arbor, Michigan

We have summarized the frequency and distribution of the rare variants encountered during the screening of 258 815 allele products, the products of 51 different loci, in 3242 predominantly Caucasian (88 %) newborns. Seventy-nine different rare variants, representing 187 occurrences, were identified. Almost 60 % (46 of 79) of the rare variants occurred as singletons while another 20 % were seen in two unrelated individuals. No rare variants were detected at 18 loci while no variants, either rare or polymorphic, were detected at 14 loci. More rare variants were identified at loci that were classified as polymorphic and also at loci where the gene products exist as a monomer. A positive relationship was observed between variant frequency, either classes or copies, and subunit molecular mass.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65173/1/j.1469-1809.1987.tb01065.x.pd

The African Surgical OutcomeS-2 (ASOS-2) Pilot Trial, a mixed-methods implementation study

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. The working hypothesis is that patients die as a result of failure to rescue following complications in the postoperative period. The African Surgical OutcomeS-2 (ASOS-2) Trial plans to test the efficacy of increased postoperative surveillance in high risk patients for decreasing perioperative morbidity and mortality. This pilot trial aimed i) to evaluate the adequacy of data produced by the data collection strategies of the ASOS-2 Trial, ii) to evaluate the fidelity of implementation of the increased postoperative surveillance intervention, and iii) to understand the acceptability, appropriateness and feasibility of the intervention and the trial processes.Methods: The ASOS-2 Pilot Trial was a mixed-methods (quantitative-qualitative) implementation study focusing on the intervention arm of the proposed ASOS-2 Trial. The intervention is increased postoperative surveillance for high-risk surgical patients. The intervention protocol was implemented at all sites for a seven-day period. A post pilot trial survey was used to collect data on the implementation outcomes.Results: 803 patients were recruited from 16 hospitals in eight African countries. The sampling and data collection strategies provided 98% complete data collection. Seventy-three percent of respondents believed that they truly provided increased postoperative surveillance to high risk patients. In reality 83/125 (66%) of high-risk patients received some form of increased postoperative surveillance. However, the individual components of the increased postoperative surveillance intervention were implemented in less than 50% of high-risk patients (excepting increasing nursing observations). The components most frequently unavailable were the ability to provide care in a higher care ward (32.1%) and assigning the patient to a bed in view of the nurses’ station (28.4%). Failure to comply with available components of the intervention ranged from 27.5% to 54.3%. The post pilot survey had a response rate of 30/40 (75%). In Likert scale questions about acceptability, appropriateness, and feasibility of the ASOS-2 intervention, 63% to 87% of respondents indicated agreement. Respondents reported barriers related to resources, trial processes, teamwork and communication as reasons for disagreement.Conclusions: The proposed ASOS-2 Trial appears to be appropriate, acceptable and feasible in Africa. This pilot trial provides support for the proposed ASOS-2 Trial. It emphasises the need for establishing trial site teams which address the needs of all stakeholders during the trial. A concerted effort must be made to help participating hospitals to increase compliance with all the components of the proposed intervention of ‘increased postoperative surveillance’ during the ASOS-2 Trial.Keywords: Trial, cluster randomised, Trial, pilot, Implementation science, Mixed methods, Mortality, Surger