1,721,427 research outputs found
Long-term mortality in a cohort of severely obese persons in Italy
No full textFew large studies on Northern European or US populations reported on mortality of severely obese individuals (BMI ≥ 40 kg/m2). We studied a historical cohort in Italy to compare its mortality with previous findings, to investigate its relationship with BMI in the >40 range, and to provide evidence useful for clinical decision-making on treatment. The cohort comprised 4,837 persons with a BMI ≥40 kg/m2 and aged ≥18 at first consultation, referred to six centers for obesity treatment between 1975 and 1996. After exclusion of persons with missing personal identification data or those untraceable, 4,498 (972 men, 3,526 women) remained for analyses. We calculated standardized mortality ratios (SMRs) and carried out Cox proportional hazards modeling. General mortality (484 deaths: 153 men, 331 women) was in excess, with SMRs (95% confidence intervals) of 2.78 (2.36-3.26) for men and 2.10 (1.88-2.34) for women. Excess mortality (i) was observed in all BMI categories, except among women weighing 40-42.4 kg/m2; (ii) increased with increasing BMI; (iii) increased less among persons recruited in recent calendar periods; (iv) was inversely related to age attained at follow-up; and (v) was due to cardiovascular and respiratory diseases and violent deaths but not malignant neoplasms. Excess mortality was similar to that observed in Northern European and US cohorts. Its steady increase with BMI levels ≥40 suggests that benefits proportional to weight reduction are expected and that even limited control may be beneficial. The smaller excess among persons recruited most recently might reflect better treatment. © 2008 The Obesity Society
Using directed acyclic graphs to consider adjustment for socioeconomic status in occupational cancer studies.
No full textThere is an ongoing debate on whether analyses of occupational studies should be adjusted for socioeconomic status (SES). In this paper directed acyclic graphs (DAGs) were used to evaluate common scenarios in occupational cancer studies with the aim of clarifying this issue. It was assumed that the occupational exposure of interest is associated with SES and different scenarios were evaluated in which (a) SES is not a cause of the cancer under study, (b) SES is not a cause of the cancer under study, but is associated with other occupational factors that are causes of the cancer, (c) SES causes the cancer under study and is associated with other causal occupational factors. These examples illustrate that a unique answer to the issue of adjustment for SES in occupational cancer studies is not possible, as in some circumstances the adjustment introduces bias, in some it is appropriate and in others both the adjusted and the crude estimates are biased. These examples also illustrate the benefits of using DAGs in discussions of whether or not to adjust for SES and other potential confounders
Feasibility of recruiting a birth cohort through the Internet: the experience of the NINFEA cohort
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
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