Disinvestment in the presence of uncertainty: Description of a novel, multi-group, disinvestment trial design and protocol for an application to reduce or cease use of mobilisation alarms for preventing falls in hospitals

Disinvestment is the removal or reduction of previously provided practices or services, and has typically been undertaken where a practice or service has been clearly shown to be ineffective, inefficient and/or harmful. However, practices and services that have uncertain evidence of effectiveness, efficiency and safety can also be considered as candidates for disinvestment. Disinvestment from these practices and services is risky as they may yet prove to be beneficial if further evidence becomes available. A novel research approach has previously been described for this situation, allowing disinvestment to take place while simultaneously generating evidence previously missing from consideration. In this paper, we describe how this approach can be expanded to situations where three or more conditions are of relevance, and describe the protocol for a trial examining the reduction and elimination of use of mobilisation alarms on hospital wards to prevent patient falls. Our approach utilises a 3-group, concurrent, non-inferiority, stepped wedge, randomised design with an embedded parallel, cluster randomised design. Eighteen hospital wards with high rates of alarm use (≥3%) will be paired within their health service and randomly allocated to a calendar month when they will transition to a “Reduced” (<3%) or “Eliminated” (0%) mobilisation alarm condition. Dynamic randomisation will be used to determine which ward in each pair will be allocated to either the reduced or eliminated condition to promote equivalence between wards for the embedded parallel, cluster randomised component of the design. A project governance committee will set non-inferiority margins. The primary outcome will be rates of falls. Secondary clinical, process, safety, and economic outcomes will be collected and a concurrent economic evaluation undertaken.

Augusta (c. AD 350–80)

London’s later Roman defences were enhanced by a series of towers, or bastions, likely to have been built in association with military campaigns in Britain in the 360s. The revived walled city housed important institutions of Roman government, several of which were later described in the Notitia Dignitatum, and was renamed Augusta. This chapter reviews the archaeological evidence for the fourth century city set within its historical context. It also summarizes the uncertain evidence of London’s first Christian communities, and considers the extent to which new institutional arrangements gave rise to new forms of public architecture.

The value of cost-free uncertain evidence

We explore the question of whether cost-free uncertain evidence is worth waiting for in advance of making a decision. A classical result in Bayesian decision theory, known as the value of evidence theorem, says that, under certain conditions, when you update your credences by conditionalizing on some cost-free and certain evidence, the subjective expected utility of obtaining this evidence is never less than the subjective expected utility of not obtaining it. We extend this result to a type of update method, a variant of Judea Pearl’s virtual conditionalization, where uncertain evidence is represented as a set of likelihood ratios. Moreover, we argue that focusing on this method rather than on the widely accepted Jeffrey conditionalization enables us to show that, under a fairly plausible assumption, gathering uncertain evidence not only maximizes expected pragmatic utility, but also minimizes expected epistemic disutility (inaccuracy).

Vision screening in newborns and early childhood

We looked at existing recommendations and supporting evidence on the effectiveness of screening for visual disorders in newborns and small infants, and in children between six months and five years of age.We conducted a literature search up to the 5th of August 2019 by using key terms and manual search in selected sources. We summarized the recommendations and the strength of the recommendations when and as reported by the authors. We summarized the main findings of systematic reviews with the certainty of the evidence as reported on the accuracy of screening tests for detecting visual alterations; the efficacy of treatment for improving visual acuity, school performance, and quality of life; and potential harms derived from vision screening and treating visual alterations.Although there is little evidence supporting its validity and effectiveness, examining all newborns for congenital cataract and retinoblastoma through the red reflex examination is widely accepted due to the severity of both diseases and the good outcomes reached by early detection and treatment.Overall, there is a moderate certainty of evidence that visual screening in children between three and five years provides a moderate net benefit, as assessed by the US Preventive Services Task Force: vision screening tests are accurate for detecting amblyopia and its risk factors, and their treatment is associated with visual improvement. There is uncertain evidence on whether vision screening in children under three years of age provides net benefits. Among populations with a low prevalence of vision abnormalities, screening the youngest is associated with an increased rate of false positives, leading to unnecessary additional assessment.

AngelChik Device Removal and Revisional Fundoplication

Gastro-oesophageal reflux disease (GORD) is a common condition in developed countries with an increasing incidence in the UK, currently estimated at 5 per 1000 person-years. Risk factors for GORD include Helicobacter pylori infection, obesity, alcohol consumption, smoking and genetic predisposition. Surgical management is performed in chronic, severe cases of GORD, refractory to medical management. There are a variety of interventional surgical techniques available and the patient in this case had placement of an AngelChik Device (AD) 30 years ago. This is now a historic device due to associated complications and this patient had it removed with revisional treatment of the patient’s GORD with Nissen Fundoplication. The patient experienced multiple post-surgical complications, namely biliary leak from the central port, pulmonary embolism and pneumonia. Following description of the case, this report will discuss the increasing incidence of late complications of AD and propose a proactive approach to these patients going forwards. It will also discuss the current uncertain evidence of a new surgical intervention called magnetic sphincter augmentation (MSA) of the lower oesophagus that has similar principles to the mechanism of an AD. From this it will emphasise that more stringent and worldwide collaboration is required when bringing a new medical device into clinical care.

Bayesian Epistemology

Everyone agrees that it is good to know. We however believe many more things than we know, which has made the notion of belief a target of recent work in epistemology. Not only do we believe propositions, we also believe them to different degrees. That beliefs come in degrees is often taken as a psychological fact and as a normative principle of rationality. The most prominent normative approach to beliefs which come in degrees is Bayesian epistemology. Bayesian degrees of belief are postulated to be represented by numbers in the unit interval [0, 1] obeying the axioms of probability. The convention is that a greater number expresses a stronger belief. The second postulate of Bayesian epistemology governs the change of beliefs whenever new evidence becomes available via updating procedures, Bayesian updating for categorical evidence and the more general Jeffrey updating for uncertain evidence.

Improving the evidence base for delivery of public goods from public money in agri-environment schemes

There is growing interest around the world in more effectively linking public payments to the provision of public goods from agriculture. However, published evidence syntheses suggest mixed, weak or uncertain evidence for many agri-environment scheme options. To inform any future “public money for public goods” based policy, further synthesis work is needed to assess the evidence-base for the full range of interventions currently funded under agri-environment schemes. Further empirical research and trials should then focus on interventions for which there is mixed or limited evidence. Furthermore, to ensure the data collected is comparable and can be synthesised effectively, it is necessary to reach agreement on essential variables and methods that can be prioritised by those conducting research and monitoring. Future policy could then prioritise public money for the public goods that can most reliably be delivered, offering better value for taxpayers and improving the provision of ecosystem services from agricultural landscapes.

Coherence of probability judgments from uncertain evidence: Does ACH help?

Although the Analysis of Competing Hypotheses method (ACH) is a structured analytic technique promoted in several intelligence communities for improving the quality of probabilistic hypothesis testing, it has received little empirical testing. Whereas previous evaluations have used numerical evidence assumed to be perfectly credible, in the present experiment we tested the effectiveness of ACH using a judgment task that presented participants with uncertain evidence varying in source reliability and information credibility. Participants (N = 227) assigned probabilities to two alternative hypotheses across six cases that systematically varied case features. Across multiple tests of coherence, the ACH group showed no advantage over a no-technique control group. Both groups showed evidence of subadditivity, unreliability (which was significantly worse in the ACH group), and overly conservative non-Bayesian judgments. The ACH group also showed pseudo-diagnostic weighting of evidence. The findings do not support the claim that ACH is effective at improving probabilistic judgment.

Attitudes and Knowledge of Australian Gastroenterologists Around the Use of Medicinal Cannabis for Inflammatory Bowel Disease

Background Medicinal cannabis (MC) is being used for symptomatic relief by many patients with inflammatory bowel disease (IBD), often independently of clinical guidance. Such use presents challenges for supporting clinicians. The aim of this study was to determine the current attitudes, knowledge, and experience of gastroenterologists toward patient use of MC for symptom management in IBD. Methods Australian gastroenterologists (n = 70) and trainees (n = 23) completed an anonymous, 30-item questionnaire, probing their knowledge, attitudes, and experience with MC in managing IBD. Survey data were collected between April and August 2019. Results Thirty-nine percent of survey respondents reported having patients using MC; however, only a minority supported use of MC in IBD (21%) or expressed a desire to prescribe (28%). Only 6% claimed good understanding of current patient access pathways and only 31% felt comfortable discussing MC with their patients. Some respondents (20%) cited adverse side effects as a reason for not wanting to prescribe, with driving impairment (64%) and impacts on the developing brain (56%) cited as significant concerns. Nonetheless, MC was ranked as less hazardous than corticosteroids, immunomodulators, and biologics by most respondents, and many (53%) were encouraging of patient participation in future clinical trials. Conclusions Specialist support for the use of MC in IBD patients is relatively low, potentially reflecting the lack of experience and knowledge with MC, uncertain evidence for efficacy, and the often-unorthodox nature of current MC use in patients. This situation may change rapidly with increased familiarity, evidence development, and education around MC prescribing.