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Robyn M. Stuart

Bio: Robyn M. Stuart is an academic researcher from University of Copenhagen. The author has contributed to research in topics: Population & Medicine. The author has an hindex of 16, co-authored 65 publications receiving 1003 citations. Previous affiliations of Robyn M. Stuart include University of Sydney & Kirby Institute.

Papers published on a yearly basis

Papers
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Posted ContentDOI
15 May 2020-medRxiv
TL;DR: The methodology of Covasim (COVID-19 Agent-based Simulator), an open-source model developed to help address the urgent need for models that can project epidemic trends, explore intervention scenarios, and estimate resource needs, is described.
Abstract: The COVID-19 pandemic has created an urgent need for models that can project epidemic trends, explore intervention scenarios, and estimate resource needs. Here we describe the methodology of Covasim (COVID-19 Agent-based Simulator), an open-source model developed to help address these questions. Covasim includes demographic information on age structure and population size; realistic transmission networks in different social layers, including households, schools, workplaces, and communities; age-specific disease outcomes; and intrahost viral dynamics, including viral-load-based transmissibility. Covasim also supports an extensive set of interventions, including non-pharmaceutical interventions, such as physical distancing, hygiene measures, and protective equipment; and testing interventions, such as symptomatic and asymptomatic testing, isolation, contact tracing, and quarantine. These interventions can incorporate the effects of delays, loss-to-follow-up, micro-targeting, and other factors. In collaboration with local health agencies and policymakers, Covasim has already been applied to examine disease dynamics and policy options in Africa, Europe, Oceania, and North America.

303 citations

Journal ArticleDOI
TL;DR: To prevent a second COVID-19 wave, relaxation of physical distancing, including reopening of schools, in the UK must be accompanied by large-scale, population-wide testing of symptomatic individuals and effective tracing of their contacts, followed by isolation of diagnosed individuals.

279 citations

Journal ArticleDOI
TL;DR: Covasim as discussed by the authors is an agent-based simulation model developed to examine epidemic dynamics and inform policy decisions in more than a dozen countries in Africa, Asia-Pacific, Europe, and North America.
Abstract: The COVID-19 pandemic has created an urgent need for models that can project epidemic trends, explore intervention scenarios, and estimate resource needs. Here we describe the methodology of Covasim (COVID-19 Agent-based Simulator), an open-source model developed to help address these questions. Covasim includes country-specific demographic information on age structure and population size; realistic transmission networks in different social layers, including households, schools, workplaces, long-term care facilities, and communities; age-specific disease outcomes; and intrahost viral dynamics, including viral-load-based transmissibility. Covasim also supports an extensive set of interventions, including non-pharmaceutical interventions, such as physical distancing and protective equipment; pharmaceutical interventions, including vaccination; and testing interventions, such as symptomatic and asymptomatic testing, isolation, contact tracing, and quarantine. These interventions can incorporate the effects of delays, loss-to-follow-up, micro-targeting, and other factors. Implemented in pure Python, Covasim has been designed with equal emphasis on performance, ease of use, and flexibility: realistic and highly customized scenarios can be run on a standard laptop in under a minute. In collaboration with local health agencies and policymakers, Covasim has already been applied to examine epidemic dynamics and inform policy decisions in more than a dozen countries in Africa, Asia-Pacific, Europe, and North America.

229 citations

Journal ArticleDOI
02 Sep 2014-Chaos
TL;DR: A Markov chain model of the surface ocean dynamics is created using short flow time trajectory data from a global ocean model to identify the five major ocean garbage patches, and partition the ocean into basins of attraction for each of the garbage patches.
Abstract: The Ekman dynamics of the ocean surface circulation is known to contain attracting regions such as the great oceanic gyres and the associated garbage patches. Less well-known are the extents of the basins of attractions of these regions and how strongly attracting they are. Understanding the shape and extent of the basins of attraction sheds light on the question of the strength of connectivity of different regions of the ocean, which helps in understanding the flow of buoyant material like plastic litter. Using short flow time trajectory data from a global ocean model, we create a Markov chain model of the surface ocean dynamics. The surface ocean is not a conservative dynamical system as water in the ocean follows three-dimensional pathways, with upwelling and downwelling in certain regions. Using our Markov chain model, we easily compute net surface upwelling and downwelling, and verify that it matches observed patterns of upwelling and downwelling in the real ocean. We analyze the Markov chain to determine multiple attracting regions. Finally, using an eigenvector approach, we (i) identify the five major ocean garbage patches, (ii) partition the ocean into basins of attraction for each of the garbage patches, and (iii) partition the ocean into regions that demonstrate transient dynamics modulo the attracting garbage patches.

107 citations

Journal ArticleDOI
TL;DR: This model is introduced and compared with existing HIV models that have been used previously to inform decisions about HIV program funding and coverage targets and there is increasing demand from stakeholders to have a tool that can perform evidence-based HIV epidemic analyses.
Abstract: Optima is a software package for modeling HIV epidemics and interventions that we developed to address practical policy and program problems encountered by funders, governments, health planners, and program implementers. Optima's key feature is its ability to perform resource optimization to meet strategic HIV objectives, including HIV-related financial commitment projections and health economic assessments. Specifically, Optima allows users to choose a set of objectives (such as minimizing new infections, minimizing HIV-related deaths, and/or minimizing long-term financial commitments) and then determine the optimal resource allocation (and thus program coverage levels) for meeting those objectives. These optimizations are based on the following: calibrations to epidemiological data; assumptions about the costs of program implementation and the corresponding coverage levels; and the effects of these programs on clinical, behavioral, and other epidemiological outcomes. Optima is flexible for which population groups (specified by behavioral, epidemiological, and/or geographical factors) and which HIV programs are modeled, the amount of input data used, and the types of outputs generated. Here, we introduce this model and compare it with existing HIV models that have been used previously to inform decisions about HIV program funding and coverage targets. Optima has already been used in more than 20 countries, and there is increasing demand from stakeholders to have a tool that can perform evidence-based HIV epidemic analyses, revise and prioritize national strategies based on available resources, set program coverage targets, amend subnational program implementation plans, and inform the investment strategies of governments and their funding partners.

90 citations


Cited by
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Journal Article
TL;DR: Male circumcision significantly reduces the risk of HIV acquisition in young men in Africa and should be integrated with other HIV preventive interventions and provided as expeditiously as possible.

1,692 citations

Journal ArticleDOI
Haidong Wang1, Timothy M. Wolock1, Austin Carter1, Grant Nguyen1  +497 moreInstitutions (214)
TL;DR: This report provides national estimates of levels and trends of HIV/AIDS incidence, prevalence, coverage of antiretroviral therapy (ART), and mortality for 195 countries and territories from 1980 to 2015.

522 citations

Journal Article
TL;DR: The aim of this bi-monthly column is to highlight Cochrane Systematic Reviews of relevance to pregnancy and childbirth and to stimulate discussion on the relevance and implications of the review for practice.
Abstract: The aim of this bi-monthly column is to highlight Cochrane Systematic Reviews of relevance to pregnancy and childbirth and to stimulate discussion on the relevance and implications of the review for practice. The Cochrane Collaboration is an international organisation that prepares and maintains high quality systematic reviews to help people make well-informed decisions about healthcare and health policy. A systematic review tries to search for, appraise and bring together existing research to answer a specific research question. The Cochrane Database of Systematic Reviews (CDSR) is published monthly online. Residents in countries with a national licence to The Cochrane Library, including the UK and Ireland, can access the Cochrane Library online, free of charge, through www.thecochranelibrary.com.

396 citations