Publications by authors named "Weijer C"

The robust design and conduct of pragmatic cluster randomised trials may be in tension with the ethical requirement to obtain written informed consent from prospective research participants. In our experience, researchers tend to focus on whether a waiver of consent is appropriate for their studies. However, pragmatic cluster randomised trials raise other important questions that have direct implications for determining when an alteration or waiver of consent is permissible.

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Background: Randomized controlled trials with pragmatic intent aim to generate evidence that directly informs clinical decisions. Some have argued that the ethical protection of informed consent can be in tension with the goals of pragmatism. But the impact of other ethical protections on trial pragmatism has yet to be explored.

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Objective: Cluster randomised trials (CRTs) are used for evaluating health-related interventions in low-income and middle-income countries (LMICs) but raise complex ethical issues. To inform the development of future ethics guidance, we aim to characterise CRTs conducted exclusively in LMICs by examining the types of clusters, settings, author affiliations and primary clinical focus and to evaluate adherence to trial registration and ethics reporting requirements over time.

Design: A systematic scoping review using the Preferred Reporting Items for Systematic Review and Meta-Analyses Extension for Scoping Reviews.

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Normothermic regional perfusion (NRP) is a surgical technique that can improve the quality and number of organs recovered for donation after the determination of death by circulatory criteria. Despite its promise, adoption of NRP has been hindered because of unresolved ethical issues. To inform stakeholders, this scoping review provides an impartial overview of the major ethical controversies surrounding NRP.

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Avian gastrulation requires coordinated flows of thousands of cells to form the body plan. We quantified these flows using their fundamental kinematic units: one attractor and two repellers constituting its Dynamic Morphoskeleton (DM). We have also elucidated the mechanistic origin of the attractor, marking the primitive streak (PS), and controlled its shape, inducing gastrulation flows in the chick embryo that are typical of other vertebrates.

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Normothermic regional perfusion (NRP) is a promising technology to improve organ transplantation outcomes by reversing ischemic injury caused by controlled donation after circulatory determination of death. However, it has not yet been implemented in Canada due to ethical questions. These issues must be resolved to preserve public trust in organ donation and transplantation.

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The administration of Pre-Mortem Interventions (PMIs) to preserve the opportunity to donate, to assess the eligibility to donate, or to optimize the outcomes of donation and transplantation are controversial as they offer no direct medical benefit and include at least the possibility of harm to the still-living patient. In this article, we describe the legal analysis surrounding consent to PMIs, drawing on existing legal commentary and identifying key legal problems. We provide an overview of the approaches in several jurisdictions that have chosen to explicitly address PMIs within codified law.

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Research teams are increasingly interested in using cluster randomized trial (CRT) designs to generate practice-guiding evidence for in-center maintenance hemodialysis. However, CRTs raise complex ethical issues. The Ottawa Statement on the Ethical Design and Conduct of Cluster Randomized Trials, published in 2012, provides 15 recommendations to address ethical issues arising within 7 domains: justifying the CRT design, research ethics committee review, identifying research participants, obtaining informed consent, gatekeepers, assessing benefits and harms, and protecting vulnerable participants.

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Background: Donor interventions, including medications, protocols, and medical devices administered to donors, can enhance transplantable organ quality and quantity and maximize transplantation success. However, there is paucity of high-quality evidence about their effectiveness, in part because of ethical, practical, and regulatory challenges, and lack of guidance about conduct of donor intervention randomized controlled trials (RCTs).

Methods: With the vision to develop authoritative guidance for conduct of donor intervention RCTs, we convened a workshop of Canadian-United Kingdom experts in organ donation and transplantation ethics, research, and policy to identify stakeholders, explore unique challenges, and develop research agenda to inform future work in this promising field.

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A cluster randomized trial is defined as a randomized trial in which intact social units of individuals are randomized rather than individuals themselves. Outcomes are observed on individual participants within clusters (such as patients). Such a design allows assessing interventions targeting cluster-level participants (such as physicians), individual participants or both.

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During vertebrate gastrulation, an embryo transforms from a layer of epithelial cells into a multilayered gastrula. This process requires the coordinated movements of hundreds to tens of thousands of cells, depending on the organism. In the chick embryo, patterns of actomyosin cables spanning several cells drive coordinated tissue flows.

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Jon Merz raises two objections to our article on the ethics of behavioral influences in trial recruitment. In this response, we defend our article against these objections. We argue that Merz's critique rests on a misunderstanding of our article, defend the daily life standard as a guardrail for leveraging cognitive biases, and argue that rejecting all behavioral influences is not a helpful nor a sustainable answer to their increasing use in trial recruitment.

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Background: There are few data on patient and public involvement (PPI) in pragmatic trials. We aimed to describe the prevalence and nature of PPI within pragmatic trials, describe variation in prevalence of PPI by trial characteristics and compare prevalence of PPI reported by trial authors to that reported in trial publications.

Methods: We applied a search filter to identify pragmatic trials published from 2014 to 2019 in MEDLINE.

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Global elimination of hepatitis C virus (HCV) will be difficult to attain without an effective HCV vaccine. Controlled human infection (CHI) studies with HCV were not considered until recently, when highly effective treatment became available. However, now that successful treatment of a deliberate HCV infection is feasible, it is imperative to evaluate the ethics of establishing a program of HCV CHI research.

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Introduction: In donation after circulatory determination of death, death is declared 5 min after circulatory arrest. This practice assumes, but does not explicitly confirm, permanent loss of brain activity. While this assumption is rooted a strong physiological rationale, paucity of direct human data regarding temporal relationship between cessation of brain activity and circulatory arrest during the dying process threatens public and healthcare provider trust in deceased organ donation.

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During gastrulation, early embryos specify and reorganise the topology of their germ layers. Surprisingly, this fundamental and early process does not appear to be rigidly constrained by evolutionary pressures; instead, the morphology of gastrulation is highly variable throughout the animal kingdom. Recent experimental results demonstrate that it is possible to generate different alternative gastrulation modes in single organisms, such as in early cnidarian, arthropod and vertebrate embryos.

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Convergence-extension in embryos is controlled by chemical and mechanical signalling. A key cellular process is the exchange of neighbours via T1 transitions. We propose and analyse a model with positive feedback between recruitment of myosin motors and mechanical tension in cell junctions.

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While randomized controlled trials are essential to health research, many of these trials fail to recruit enough participants. Approaching recruitment through the lens of behavioral science can help trialists to understand influences on the decision to participate and use them to increase recruitment. Although this approach is promising, the use of behavioral influences during recruitment is in tension with the ethical principle of respect for persons, as at least some of these influences could be used to manipulate potential participants.

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Introduction: To improve dementia care delivery for persons across all backgrounds, it is imperative that health equity is integrated into pragmatic trials.

Methods: We reviewed 62 pragmatic trials of people with dementia published 2014 to 2019. We assessed health equity in the objectives; design, conduct, analysis; and reporting using PROGRESS-Plus which stands for Place of residence, Race/ethnicity, Occupation, Gender/sex, Religion, Education, Socioeconomic status, Social capital, and other factors such as age and disability.

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Objectives: Normal saline (NS) and Ringer's lactate (RL) are the most common crystalloids used for fluid therapy. Despite evidence of possible harm associated with NS (eg, hyperchloremic metabolic acidosis, impaired kidney function and death), few large multi-centre randomised trials have evaluated the effect of these fluids on clinically important outcomes. We conducted a pilot trial to explore the feasibility of a large trial powered for clinically important outcomes.

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