1,721,105 research outputs found
Potential impact of prison-based interventions on hepatitis C transmission among people who inject drugs in Montréal, Canada Insights from mathematical modelling
No full textBackgroundThe Canadian burden of chronic hepatitis C (HCV) is highly concentrated among people who inject drugs (PWID), a population with high incarceration rates in the provincial prison system, where the duration of sentences is less than 2 years. PWID and people in prison have been identified as key populations for HCV transmission and to eliminate HCV as a public health threat by 2030. However, the treatment and care continuum for HCV in provincial prisons, as well as the link with community services still represent challenges because of high turnover rates, frequent prison transfers, and the lack of standardized care pathways. Because of short-course direct-acting antivirals (DAA) with high safety and tolerability, people in provincial prisons could be prioritized for treatment during or after their stay in prison. However, universal HCV screening has yet to be implemented in these settings, which precludes case identification. Further, the heightened risk of HCV acquisition and transmission post-release creates a potential for reinfection among individuals treated in prison. There is an urgent need to build the evidence base regarding prison-based interventions to reduce HCV transmission.AimsThis study aims to assess the potential population-level impact of prison-based intervention strategies on HCV transmission among PWID in Montréal.MethodsA dynamic compartmental model of HCV transmission among PWID in Montréal was developed. The model is stratified by sex (male, female), incarceration status (never, currently, recently or previously released), and injecting status (active, past, and on opioid agonist therapy). It was calibrated in a Bayesian framework to local epidemiological data from bio-behavioural surveys conducted annually among PWID (2003-2014) and twice among the general prison population (2003, 2014). Among other scenarios, three broad types of intervention strategies were explored: 1) prison-based test-and-treat (90% tested, and 75% treated in prison), 2) linkage to care post-release (90% tested in prison, and 75% treated post-release), and 3) risk reduction interventions, which halve the elevated post-release risk. The impact of these interventions was estimated over ten years from 2018 on prevalence (P), incidence (I), and prevented fraction of new infections (PF), as compared to a status quo counter-factual where no specific intervention is implemented in prison for HCV.ResultsThe model reproduces the HCV epidemic among PWID in Montréal, both inside and outside of prison settings. After ten years, prison-based test-and-treat (P: 27%(95%CrI = 20−34%); I: 19%(95%CrI = 9−28%); PF: 7%(95%CrI = 4−10%)) and linkage to care post-release (P: 30%(95%CrI = 22−38%); I: 23%(95%CrI = 11−33%); PF: 9%(95%CrI = 5−14%)) would both reduce prevalence and slow down HCV transmission among active PWID in Montréal. Combined with risk reduction, test-and-treat interventions (P: 32%(95%CrI = 25−41%); I: 30%(95%CrI = 17−41%); PF: 10%(95%CrI = 6−17%)), and linkage to care (P: 36%(95%CrI = 28−45%); I: 33%(95%CrI = 20−45%); PF: 13%(95%CrI = 7−20%)) would lead to a sustained impact.ConclusionThese results suggest that offering universal HCV testing in prison and increasing treatment for PWID in or upon release from provincial prisons could change the course of the HCV epidemic in Montéal. Among all scenarios, models of care that integrate risk reduction measures post-release have the greatest potential to reduce HCV transmission among PWID.ContexteLa transmission du virus de l’hépatite C (VHC) est principalement concentrée chez les utilisateurs de drogues injectables (UDI), une population souvent en contact avec le système de détention provincial où les sentences sont plus courtes que deux ans. Les UDI et les personnes en prison ont été identifiés comme des populations prioritaires pour l’élimination du VHC en tant que menace pour la santé publique. Néanmoins, la chaîne de soin en prison et la liaison avec les soins de santé dans la collectivité demeurent des défis de taille pour les services correctionnels en raison du taux de roulement, des transferts fréquents et de l’absence de cheminement clinique standardisé. Avec l’arrivée des antiviraux à action directe (AAD) efficaces, dont la durée de traitement est courte, les personnes en prison pourraient être priorisées pour un traitement durant ou après leur incarcération. Cependant, le dépistage systématique du VHC n’est pas implanté dans les prisons provinciales, ce qui freine l’identification de nouveaux cas. De plus, les comportements à risque après la libération impliquent un potentiel de réinfection chez les individus traités en prison. Dans ce contexte, il est urgent d'évaluer de façon robuste les interventions ciblant le VHC en milieu carcéral.ObjectifÉvaluer l’impact potentiel de stratégies d’intervention en milieu carcéral sur la transmission du VHC à l’échelle de la population des UDI de Montréal.MéthodesUn modèle mathématique dynamique de la transmission du VHC chez les UDI de Montréal a été développé. Celui-ci est stratifié par sexe (homme, femme), statut d’incarcération (jamais, présentement, récemment libéré, déjà incarcéré) et statut d’injecteur (UDI actif, passé, sous traitement par agoniste opioïde). Le modèle a été calibré à des données locales provenant de sondages bio-comportementaux menés dans la population carcérale (2003, 2014) et annuellement chez les UDI (2003-2014). Trois types d’intervention en prison ont été explorés : 1) le dépistage et le traitement en prison (90% testés et 75% traités en prison), 2) la prise en charge à la libération (90% testés en prison, 75% traités à la libération) et 3) la réduction du risque à la libération (réduction de 50%). L’impact a été évalué sur dix ans à partir de 2018 par rapport à un scénario gardant les taux de dépistage et de traitement constants alors qu’aucune intervention n’est initiée en prison. L’évaluation a été réalisée en termes de réduction relative de la prévalence (P) et de l’incidence (I), ainsi qu’en termes de fraction de nouvelles infections prévenues (IP).RésultatsLe modèle reproduit l’épidémie de VHC chez les UDI de Montréal, en prison et dans la collectivité. Après dix ans, l’intervention de dépistage et de traitement en prison (P : 27%(95%CrI = 20−34%); I : 19%(95%CrI = 9−28%); IP : 7%(95%CrI = 4−10%)) et de prise en charge à la libération (P : 30%(95%CrI = 22−38%) ; I : 23%(95%CrI = 11−33%) ; PF : 9%(95%CrI = 5 − 14%)) réduisent toutes deux la prévalence en plus de ralentir la transmission du VHC chez les UDI de Montréal. En présence de réduction du risque à la libération, le dépistage et le traitement en prison (P : 32%(95%CrI = 25−41%) ; I : 30%(95%CrI = 17−41%) ; PF : 10%(95%CrI = 6−17%)) ainsi que la prise en charge à la libération (P : 36%(95%CrI = 28−45%) ; I : 33%(95%CrI = 20−45%) ; PF : 13%(95%CrI = 7−20%)) ont un impact soutenu sur la prévalence et la transmission du virus.ConclusionCes résultats suggèrent qu’offrir le dépistage systématique du VHC en prison et le traitement des cas chroniques pendant ou après l’incarcération, pourraient potentiellement changer la trajectoire de l’épidémie chez les UDI de Montréal. Parmi les différents scénarios, les modèles de soins intégrant la réduction du risque peuvent avoir l'impact le plus important pour diminuer la transmission du VHC
Attribution of reductions in malaria prevalence in Dar es Salaam, Tanzania – Authors' reply
Get PDFWe thank Mathieu Maheu-Giroux and Marcia Castro for their Correspondence about our Article.1 Regarding concerns about the stepped-wedge design of the larviciding scale-up in our study, we agree and also note that scale-up was not randomised, but rather introduced earliest to the best-prepared wards. However, such compromises are normal and healthy in pragmatic assessments of effectiveness under realistic programmatic conditions, rather than efficacy under artificially controlled experimental conditions. As acknowledged in the discussion and emphasised in the title, we also agree that evidence for window screening impact is purely observational, and that long-overdue, cluster-randomised, experimentally controlled analyses of well developed delivery practices for both these supplementary vector control measures are urgently needed.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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