1,720,965 research outputs found
Bounds for the probability of causation: a new formulation in Mediation Analysis
No full textGiven even the best evidence for the dependence of an outcome vari-
able on an exposure variable, we can typically only provide bounds for the
"probability of causation" in the case of an individual who has developed
the disease after being exposed. We show how these bounds can be im-
proved or adapted if further information becomes available. In addition
to the actual literature we provide a new formulation in the case of Medi-
ation Analysis. Mediation studies the relationship between two variables
when a third is involved in the causal pathway. In particular we will show
how this mediated eect can be bounded in the case of no direct effect
The probability of causation
No full textMany legal cases require decisions about causality, responsibility or blame, and these may be based on statistical data. However, causal inferences from such data are beset by subtle conceptual and practical difficulties, and in general it is, at best, possible to identify the 'probability of causation' as lying between certain empirically informed limits. These limits can be refined and improved if we can obtain additional information, from statistical or scientific data, relating to the internal workings of the causal processes. In this article we review and extend recent work in this area, where additional information may be available on covariate and/or mediating variables
Birth Order, Birth Weight and Asthma: how to assess mediation and the presence of Unmeasured Confounding
No full textIf the goal is to measure the causal relation between two variables when a third is involved and plays the role of mediator, it is essential to explicitly define the relational assumptions among these and others relevant variables. However if any of this assumptions are not met, estimates of mediated effects may be affected
by bias. One example where this occurs is the widely discussed situation known as
the Birth Weight paradox which arises when birth weight is the mediator of interest and unmeasured confounders affect the mediator-outcome relation. In this paper we will focus on a setting where such paradox might arise where birth order act as the exposure for childhood asthma (by age 1.5). After estimating the direct and
indirect effects, we give a plausible graphical explanation of the empirical results and explore the magnitude of the causal relations using sensitivity analysis
Un quadro nazionale delle tematiche trattate dai giovani in epidemiologia: un confronto prima e dopo il Covid-19
No full textIntroduction: Epidemiology is increasingly involved on a wide variety of topics and to engage different professionals and disciplines in an increasingly active way. A fundamental role is played by young researchers active in Italian epidemiology who create opportunities for meeting and discussion, in the name of multidisciplinarity and integration of different skills. Objective: The aim of this paper is to provide a detailed description of the topics most frequently studied in epidemiology by young people and to highlight any changes in these topics in the pre- and post-Covid-19 workplaces. Methods: All abstracts submitted in the years 2019 and 2022 by young participants in the Maccacaro Prize, an annual award aimed at Italian association of epidemiology (Aie) conference addressed to people under 35 years of age, were considered. In addition to the comparison of the topics, a comparison of the related work structures and their geographical location was carried out by grouping the research centres into three Italian geographical regions: north, centre and south/islands. Results: Between 2019 and 2022, the number of abstracts participating in the Maccacaro Prize increased. The interest in topics related to infectious diseases, vaccines, and pharmaco-epidemiology has sharply increased, while in environmental and maternal and child epidemiology it has moderately increased. Social epidemiology, health promotion and prevention, as well as clinical and evaluative epidemiology, have experienced a decrease in interest. Finally, after analysing the geographical distribution of reference centres, it was discovered that certain regions, such as Piedmont, Lombardy, Veneto, Emilia-Romagna, Tuscany and Latium, have a strong and consistent presence of young people in the field of epidemiology. Conversely, there is a small number of young professionals working in this field in other Italian regions, especially in Southern regions. Conclusions: The pandemic has changed our personal and working habits, but it has also played a fundamental role in making epidemiology known. The increase in young people joining an association such as the Aie is a clear sign of the growing interest in this discipline
Bounding the probability of causation in mediation analysis
No full textGiven empirical evidence for the dependence of an outcome variable on an exposure variable, we can typically only provide bounds for the “probability of causation” in the case of an individual who has developed the outcome after being exposed. We show how these bounds can be adapted or improved if further information becomes available. In addition to reviewing existing work on this topic, we
provide a new analysis for the case where a mediating variable can be observed. In particular, we show how the probability of causation can be bounded when there is no direct effect and no confounding
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
- …
