Use and cumulation of evidence from modelling studies to inform policy on food taxes and subsidies: biting off more than we can chew?

Abstract Background Food tax-subsidy policies are proposed to hold promise for helping to produce healthier patterns of food purchasing and consumption at population level. Evidence for their effects derives largely from simulation studies that explore the potential effects of untried policies using a mathematical modelling framework. This paper provides a critique first of the nature of the evidence derived from such simulation studies, and second of the challenges of cumulating that evidence to inform public health policy. Discussion Effects estimated by simulation studies of food taxes and subsidies can be expected to diverge in potentially important ways from those that would accrue in practice because these models are simplified, typically static, representations of complex adaptive systems. The level of confidence that can be placed in modelled estimates of effects is correspondingly low, and the level of associated uncertainty is high. Moreover, evidence from food tax-subsidy simulation studies cannot meaningfully be cumulated using currently available quantitative evidence synthesis methods, to reduce uncertainty about effects. Summary Simulation studies are critical for the initial phases of an incremental research process, for drawing together diverse evidence and exploring potential longer-term effects. While simulation studies of food taxes and subsidies provide a valuable and necessary input to the formulation of public health policy in this area, they are unlikely to be sufficient, and policy makers should not place excessive reliance on evidence from such studies, either singly or cumulatively. To reflect known and unknown limitations of the models, results of such studies should be interpreted cautiously as tentative projections. Modelling studies should increasingly be integrated with more empirical studies of the effects of food tax and subsidy policies in practice

Surfactant amplifies yield-stress effects in the capillary instability of a film coating a tube

To assess how the presence of surfactant in lung airways alters the flow of mucus that leads to plug formation and airway closure, we investigate the effect of insoluble surfactant on the instability of a viscoplastic liquid coating the interior of a cylindrical tube. Evolution equations for the layer thickness using thin-film and long-wave approximations are derived that incorporate yield-stress effects and capillary and Marangoni forces. Using numerical simulations and asymptotic analysis of the thin-film system, we quantify how the presence of surfactant slows growth of the Rayleigh-Plateau instability, increases the size of initial perturbation required to trigger instability and decreases the final peak height of the layer. When the surfactant strength is large, the thin-film dynamics coincide with the dynamics of a surfactant-free layer but with time slowed by a factor of four and the capillary Bingham number, a parameter proportional to the yield stress, exactly doubled. By solving the long-wave equations numerically, we quantify how increasing surfactant strength can increase the critical layer thickness for plug formation to occur and delay plugging. The previously established effect of the yield stress in suppressing plug formation [Shemilt et al., J. Fluid Mech., 2022, vol. 944, A22] is shown to be amplified by introducing surfactant. We discuss the implications of these results for understanding the impact of surfactant deficiency and increased mucus yield stress in obstructive lung diseases.Comment: 33 pages, 10 figure

Cost-effectiveness of Microsoft Academic Graph with machine learning for automated study identification in a living map of coronavirus disease 2019 (COVID-19) research

BACKGROUND: Conventionally, searching for eligible articles to include in systematic reviews and maps of research has relied primarily on information specialists conducting Boolean searches of multiple databases and manually processing the results, including deduplication between these multiple sources. Searching one, comprehensive source, rather than multiple databases, could save time and resources. Microsoft Academic Graph (MAG) is potentially such a source, containing a network graph structure which provides metadata that can be exploited in machine learning processes. Research is needed to establish the relative advantage of using MAG as a single source, compared with conventional searches of multiple databases. This study sought to establish whether: (a) MAG is sufficiently comprehensive to maintain our living map of coronavirus disease 2019 (COVID-19) research; and (b) eligible records can be identified with an acceptably high level of specificity. METHODS: We conducted a pragmatic, eight-arm cost-effectiveness analysis (simulation study) to assess the costs, recall and precision of our semi-automated MAG-enabled workflow versus conventional searches of MEDLINE and Embase (with and without machine learning classifiers, active learning and/or fixed screening targets) for maintaining a living map of COVID-19 research. Resource use data (time use) were collected from information specialists and other researchers involved in map production. RESULTS: MAG-enabled workflows dominated MEDLINE-Embase workflows in both the base case and sensitivity analyses. At one month (base case analysis) our MAG-enabled workflow with machine learning, active learning and fixed screening targets identified n=469 more new, eligible articles for inclusion in our living map – and cost £3,179 GBP ($5,691 AUD) less – than conventional MEDLINE-Embase searches without any automation or fixed screening targets. CONCLUSIONS: MAG-enabled continuous surveillance workflows have potential to revolutionise study identification methods for living maps, specialised registers, databases of research studies and/or collections of systematic reviews, by increasing their recall and coverage, whilst reducing production costs

Issues in the incorporation of economic perspectives and evidence into Cochrane reviews

Methods for systematic reviews of the effects of health interventions have focused mainly on addressing the question of 'What works?' or 'Is this intervention effective in achieving one or more specific outcomes?' Addressing the question 'Is it worth it given the resources available?' has received less attention. This latter question can be addressed by applying an economic lens to the systematic review process.This paper reflects on the value and desire for the consideration by end users for coverage of an economic perspective in a Cochrane review and outlines two potential approaches and future directions

Altering the availability or proximity of food, alcohol and tobacco products to change their selection and consumption

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: 1. To assess the impact of altering the availability or proximity of: a) food products (including non-alcoholic beverages); b) alcohol products; and c) tobacco products on their selection or consumption. 2. For each of the above products, to assess the extent to which the impact of such interventions is modified by: i) study characteristics; ii) intervention characteristics; and iii) participant characteristics.Production of this protocol was funded by the Department of Health Policy Research Programme in England ([PR-UN-0409-10109] Policy Research Unit in Behaviour and Health). The views expressed are those of the authors and not necessarily those of the Department of Health in England

An evaluation of Cochrane Crowd found that crowdsourcing produced accurate results in identifying randomised trials

BACKGROUND: Filtering the deluge of new research to facilitate evidence synthesis has proven to be unmanageable using current paradigms of search and retrieval. Crowdsourcing, a way of harnessing the collective effort of a 'crowd' of people, has the potential to support evidence synthesis by addressing this information overload created by the exponential growth in primary research outputs. Cochrane Crowd, Cochrane's citizen science platform, offers a range of tasks aimed at identifying studies related to healthcare. Accompanying each task are brief, interactive training modules and agreement algorithms that help ensure accurate collective decision-making. OUR OBJECTIVES WERE: (1) to evaluate the performance of Cochrane Crowd in terms of its accuracy, capacity and autonomy; and (2) to examine contributor engagement across three tasks aimed at identifying randomised trials. STUDY DESIGN: Crowd accuracy was evaluated by measuring the sensitivity and specificity of crowd screening decisions on a sample of titles and abstracts, compared with 'quasi gold-standard' decisions about the same records using the conventional methods of dual screening. Crowd capacity, in the form of output volume, was evaluated by measuring the number of records processed by the crowd, compared with baseline. Crowd autonomy, the capability of the crowd to produce accurate collectively-derived decisions without the need for expert resolution, was measured by the proportion of records that needed resolving by an expert. RESULTS: The Cochrane Crowd community currently has 18,897 contributors from 163 countries. Collectively, the Crowd has processed 1,021,227 records, helping to identify 178,437 reports of randomised trials (RCTs) for Cochrane's Central Register of Controlled Trials. The sensitivity for each task was 99.1% for the randomised controlled trial identification task (RCT ID), 99.7% for the randomised controlled trial identification task of trial from ClinicalTrials.gov (CT ID) and 97.7% for identification of randomised controlled trials from the International Clinical Trials Registry Platform (ICTRP ID). The specificity for each task was 99% for RCT ID, 98.6% for CT ID and 99.1% for ICTRP ID. The capacity of the combined Crowd and machine learning workflow has increased five-fold in six years, compared with baseline. The proportion of records requiring expert resolution across the tasks ranged from 16.6% to 19.7%. CONCLUSION: Cochrane Crowd is sufficiently accurate and scalable to keep pace with the current rate of publication (and registration) of new primary studies. It has also proved to be a popular, efficient and accurate way for a large number of people to play an important voluntary role in health evidence production. Cochrane Crowd is now an established part of Cochrane's effort to manage the deluge of primary research being produced

Economics methods in Cochrane systematic reviews of health promotion and public health related interventions.

Peer reviewedPublisher PD

Producing Cochrane systematic reviews—a qualitative study of current approaches and opportunities for innovation and improvement

Background: Producing high-quality, relevant systematic reviews and keeping them up to date is challenging. Cochrane is a leading provider of systematic reviews in health. For Cochrane to continue to contribute to improvements in heath, Cochrane Reviews must be rigorous, reliable and up to date. We aimed to explore existing models of Cochrane Review production and emerging opportunities to improve the efficiency and sustainability of these processes. Methods: To inform discussions about how to best achieve this, we conducted 26 interviews and an online survey with 106 respondents. Results: Respondents highlighted the importance and challenge of creating reliable, timely systematic reviews. They described the challenges and opportunities presented by current production models, and they shared what they are doing to improve review production. They particularly highlighted significant challenges with increasing complexity of review methods; difficulty keeping authors on board and on track; and the length of time required to complete the process. Strong themes emerged about the roles of authors and Review Groups, the central actors in the review production process. The results suggest that improvements to Cochrane's systematic review production models could come from improving clarity of roles and expectations, ensuring continuity and consistency of input, enabling active management of the review process, centralising some review production steps; breaking reviews into smaller "chunks", and improving approaches to building capacity of and sharing information between authors and Review Groups. Respondents noted the important role new technologies have to play in enabling these improvements. Conclusions: The findings of this study will inform the development of new Cochrane Review production models and may provide valuable data for other systematic review producers as they consider how best to produce rigorous, reliable, up-to-date reviews

Implementation of the national antimicrobial stewardship competencies for UK undergraduate healthcare professional education within undergraduate pharmacy programmes: a survey of UK schools of pharmacy

Background Pharmacists play a key role in antimicrobial stewardship (AMS). Consensus-based national AMS competencies for undergraduate healthcare professionals in the UK reflect the increasing emphasis on competency-based healthcare professional education. However, the extent to which these are included within undergraduate pharmacy education programmes in the UK is unknown. Objectives To explore which of the AMS competencies are delivered, including when and at which level, within UK undergraduate MPharm programmes.Methods A cross-sectional online questionnaire captured the level of study of the MPharm programme in which each competency was taught, the method of delivery and assessment of AMS education, and examples of student feedback. Results Ten institutions completed the survey (33% response rate). No institution reported covering all 54 AMS competencies and 5 of these were taught at half or fewer of the institutions. Key gaps were identified around taking samples, communication, outpatient parenteral antimicrobial therapy and surgical prophylaxis. The minimum time dedicated to AMS teaching differed between institutions (range 9-119 h), teaching was generally through didactic methods, and assessment was generally through knowledge recall and objective structured clinical examinations. Feedback from students suggests they find AMS and antimicrobial resistance (AMR) to be complex yet important topics. Conclusions UK schools of pharmacy should utilize the competency framework to identify gaps in their AMS, AMR and infection teaching. To prepare newly qualified pharmacists to be effective at delivering AMS and prescribing antimicrobials, schools of pharmacy should utilize more simulated environments and clinical placements for education and assessment of AMS

Approaches, Strategies and Theoretical and Practice-Based Research Methods to investigate and archive video art:Some reflections from the REWIND projects

This paper will discuss methodologies, approaches and issues, emerging out of three major research projects that have investigated early histories of video art in Europe: REWIND (2004 ongoing), REWINDItalia (2011-2014) and EWVA (2015-2018). The paper will discuss how the projects have engaged with the history of the apparatus, the identity and status of the artworks, preservation methods, and the legacy of these video artworks today. A particular focus will be on semi-structured questionnaires for interviews structured to capture oral histories, memories and recollections, that in some cases would have been otherwise lost to future knowledge and the uncovering of lost artworks and their available documentation. The speakers directly involved in the projects - will discuss solutions, risks and experiences encountered in the projects and future research perspectives for re-covering, collecting, archiving and narrating the histories of early video art in Europe. The paper will discuss also different practice-based research methods, platforms and engagement strategies, including re-installation and re-enactment