1,721,011 research outputs found
24 weeks of Pilates-aerobic and educative training to improve body fat mass in elderly Serbian women
Full text linkAnne WS Rutjes,1 Marcello Di Nisio2,31Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland; 2Department of Medical, Oral, and Biotechnological Sciences, University G D'Annunzio of Chieti-Pescara, Chieti, Italy; 3Department of Vascular Medicine, Academic Medical Center, Amsterdam, the NetherlandsWe read with interest the article by Ruiz-Montero et al, in which the authors used a before-and-after study design to examine changes in body composition (fat mass and lean body mass) related to an aerobic-Pilates program in elderly Serbian women.1 The authors concluded that "a combined program of aerobic and Pilates, carried out under the supervision of an instructor, at least twice a week, produces health benefits in functionally independent women over the age of 60". This conclusion is overly optimistic and not supported by the evidence provided. View original paper by Ruiz-Montero and colleagues
Systematic reviews of diagnostic tests in cancer: review of methods and reporting
No full textObjectives To assess the methods and reporting of systematic reviews of diagnostic tests. Data sources Systematic searches of Medline, Embase, and five other databases identified reviews of tests used in patients with cancer. Of these, 89 satisfied our inclusion criteria of reporting accuracy of the test compared with a reference test, including an electronic search, and published since 1990. Review methods All reviews were assessed for methods and reporting of objectives, search strategy, participants, clinical setting, index and reference tests, study design, study results, graphs, meta-analysis, quality, bias, and procedures in the review. We assessed 25 randomly selected reviews in more detail. Results 75% (67) of the reviews stated inclusion criteria, 49% (44) tabulated characteristics of included studies, 40% (36) reported details of study design, 17% (15) reported on the clinical setting, 17% (15) reported on the severity of disease in participants, and 49% (44) reported on whether the tumours were primary, metastatic, or recurrent. Of the 25 reviews assessed in detail, 68% (17) stated the reference standard used in the review, 36% (9) reported the definition of a positive result for the index test, and 56% (14) reported sensitivity, specificity, and sample sizes for individual studies. Of the 89 reviews, 61% (54) attempted to formally synthesise results of the studies and 32% (29) reported formal assessments of study quality. Conclusions Reliability and relevance of current systematic reviews of diagnostic tests is compromised by poor reporting and review methods. <br/
Diagnostic accuracy of D-dimer test for exclusion of venous thromboembolism: a systematic review
No full textBACKGROUND: The reported diagnostic accuracy of the D-dimer test for exclusion of
deep vein thrombosis (DVT) and pulmonary embolism (PE) varies. It is unknown to
what extent this is due to differences in study design or patient groups, or to
genuine differences between D-dimer assays.
METHODS: Studies evaluating the diagnostic accuracy of the D-dimer test in the
diagnosis of venous thromboembolism were systematically searched for in the
MEDLINE and EMBASE databases up to March 2005. Reference lists of all included
studies and of reviews related to the topic of the present meta-analysis were
manually searched for other additional potentially eligible studies. Two
reviewers independently extracted study characteristics using standardized forms.
RESULTS: In total, 217 D-dimer test evaluations for DVT and 111 for PE were
analyzed. Several study design characteristics were associated with systematic
differences in diagnostic accuracy. After adjustment for these features, the
sensitivities of the D-dimer enzyme-linked immunofluorescence assay (ELFA) (DVT
96%; PE 97%), microplate enzyme-linked immunosorbent assay (ELISA) (DVT 94%; PE
95%), and latex quantitative assay (DVT 93%; PE 95%) were superior to those of
the whole-blood D-dimer assay (DVT 83%; PE 87%), latex semiquantitative assay
(DVT 85%; PE 88%) and latex qualitative assay (DVT 69%; PE 75%). The latex
qualitative and whole-blood D-dimer assays had the highest specificities (DVT
99%, 71%; PE 99%, 69%).
CONCLUSIONS: Compared to other D-dimer assays, the ELFA, microplate ELISA and
latex quantitative assays have higher sensitivity but lower specificity,
resulting in a more confident exclusion of the disease at the expense of more
additional imaging testing. These conclusions are based on the most up-to-date
and extensive systematic review of the topic area, including 184 articles, with
328 D-dimer test evaluations
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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