1,720,968 research outputs found
Effect of skin tone on the accuracy of the estimation of arterial oxygen saturation by pulse oximetry: a systematic review
Full text linkBackground: pulse oximetry derived oxygen saturation (SpO2) is an estimate of true arterial oxygen saturation (SaO2). The aim of this review was to evaluate available evidence determining the effect of skin tone on the ability of pulse oximeters to accurately estimate SaO2.Methods: literature was screened to identify clinical and non-clinical studies enrolling adults and children when SpO2 was compared to a paired co-oximetry SaO2 value. We searched literature databases from their inception to March 20th 2023. Risk of bias (RoB) was assessed using the QUADAS-2 tool. Certainty of assessment was evaluated using the GRADE tool.Results: forty-four studies were selected reporting on at least 222,644 participants (6121 of whom were children) and 733,722 paired SpO2-SaO2 measurements. Methodologies included laboratory studies, prospective clinical and retrospective clinical studies. A high RoB was detected in 64% of studies and there was considerable heterogeneity in study design, data analysis and reporting metrics. Only 11 (25%) studies measured skin tone in 2353 (1.1%) participants; the remainder reported participant ethnicity. 68,930 (31.0%) participants were of non-White ethnicity or had non-light skin tones. The majority of studies reported overestimation of SaO2 by pulse oximetry in participants with darker skin tones or from ethnicities assumed to have darker skin tones. Several studies reported no inaccuracy related to skin tone. Meta-analysis of the data was not possible.Conclusion: pulse oximetry may overestimate true SaO2 in people with darker skin tones. The clinical relevance of this bias remains unclear, but its magnitude is likely to greater when SaO2 is lower.<br/
Influence of external peer reviewer scores for funding applications on funding board decisions: A retrospective analysis of 1561 reviews
Full text linkObjectives To evaluate the influence of external peer reviewer scores on the National Institute for Health Research (NIHR) research funding board decisions by the number of reviewers and type of reviewer expertise Design Retrospective analysis of external peer review scores for shortlisted full applications for funding (280 funding applications, 1236 individual reviewers, 1561 review scores) Setting Four applied health research funding programmes of NIHR, UK Main outcome measures Board decision to fund or not fund research applications Results The mean score of reviewers predicted funding decisions better than individual reviewer scores (area under the receiver operating characteristic (ROC) curve 075, 95% CI 069 to 081 compared with 062, CI 059 to 065) There was no substantial improvement in how accurately mean reviewer scores predicted funding decisions when the number of reviewers increased above 4 (area under ROC curve 075, CI 059 to 091 for four reviewers; 080, CI 067 to 092 for seven or more) Reviewers with differing expertise influenced the board's decision equally, including public and patient reviewers (area under ROC curves from 057, CI 047 to 066 for health economists to 064, CI 057 to 070 for subject-matter experts) The areas under the ROC curves were quite low when using reviewers' scores, confirming that boards do not rely solely on those scores alone to make their funding decisions, which are best predicted by the mean board score Conclusions Boards value scores that originate from a diverse pool of reviewers On the basis of independent reviewer score alone, there is no detectable benefit of using more than four reviewer scores in terms of their influence on board decisions, so to improve efficiency, it may be possible to avoid using larger numbers of reviewers The funding decision is best predicted by the board score</p
Statistical inference about bivariate survival data with semi-competing risks using copulas
Full text linkBivariate, semi-competing risk data are survival endpoints where a terminal event can censor a non-terminal event, but not vice versa. An example is the endpoints of graft failure and death; death can censor graft failure, but graft failure cannot censor death. There are potential correlations between these endpoints as they are measured on the same individual. Traditional methods of calculating correlations cannot be used directly as censoring can occur on one or both survival endpoints. We develop methods using a copula-based approach to study the dependence structures between two survival endpoints while the marginal distributions are fixed. We use several copulas to estimate the correlation between survival endpoints as each copula has a different dependence structure. We apply these methods to clinical examples in renal transplantation and HIV/AIDS. We include covariates to examine how the correlation and the hazard rates are associated with individual characteristics. The misspecification of both the copula function and the marginal survival distributions are investigated using simulation studies. Finally, we extend our methods to include individuals with incomplete survival outcomes. Our analysis indicates that the correlation between graft failure and death following transplant is affected by covariates. Our simulation studies conclude that the copula models with both the marginal distribution and the association parameters having a dependence on covariates provide improved estimates of the hazard ratios for the non-terminal event, compared to the Cox proportional hazards model. Simulation studies investigating misspeci cation find that the misspecification of both the survival distribution and copula function can increase the bias of the hazard ratios and correlation coeffcients. We use the AIC to choose between the survival distributions and copula functions. We found that the correct model is chosen in the majority of data sets at strong correlations. The presented copula models can be used to analyse bivariate, semi-competing risk data with a variety of univariate and multivariate structures
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
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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