Search results for "Confidence"
showing 10 items of 1394 documents
Predicting school students’ physical activity intentions in leisure-time and school recess contexts: Testing an integrated model based on self-determ…
2021
BackgroundIdentifying psychological correlates of children's physical activity intentions may signpost potentially modifiable targets for interventions aimed at promoting physical activity participation. School recess and leisure-time outside of school are appropriate contexts in which such interventions may be delivered. However, few studies have identified correlates of physical activity intentions in these environments. Examining correlates in these contexts may provide formative evidence on which to base interventions to promote physical activity.PurposeThe current study adopted an integrated theoretical model to test relations between motivational constructs from self-determination the…
Sorafenib in advanced hepatocellular carcinoma – We have won a battle not the war
2008
Sorafenib in advanced hepatocellular carcinoma. Llovet JM, Ricci S, Mazzaferro V, Hilgard P, Gane E, Blanc JF, de Oliveira AC, Santoro A, Raoul JL, Forner A, Schwartz M, Porta C, Zeuzem S, Bolondi L, Greten TF, Galle PR, Seitz JF, Borbath I, Haussinger D, Giannaris T, Shan M, Moscovici M, Voliotis D, Bruix J; SHARP Investigators Study Group. Background No effective systemic therapy exists for patients with advanced hepatocellular carcinoma. A preliminary study suggested that sorafenib, an oral multi-kinase inhibitor of the vascular endothelial growth factor receptor, the platelet-derived growth factor receptor, and Raf may be effective in hepatocellular carcinoma. Methods In this multicente…
Echocardiographic Image Analysis Based on the Evaluation of first Order Speckle Statistics
1992
Basic theoretical considerations on the statistical properties of the speckle phenomenon indicate that a conventional quantization (intervals of uniform width) of the received and envelope detected RF — signal is not adequate. We therefore propose a quantization scheme which is based on the application of quantization intervals producing always the same confidence level (adaptive quantization). The advantages are: homogenous distribution of speckle noise reduction to about 10 – 20 significant quantization levels (with neglectable loss of morphological information) quantitative measure (confidence level) of the separability of regions represented with different quantization levels. We furthe…
FEV1 and FVC predict all-cause mortality independent of cardiac function - Results from the population-based Gutenberg Health Study.
2017
Abstract Background Lung function has previously been related to increased mortality. Whether pulmonary impairment is associated with an increased mortality independent of cardiac dysfunction remains unclear. Methods In 15010 individuals from the general population (age range 35–74years, 51% men) in the Gutenberg Health Study we performed spirometry and transthoracic echocardiography. N-terminal pro-B-type natriuretic peptide (Nt-proBNP) and high-sensitive troponin I (hsTnI) were measured in all individuals. 1819 individuals with pulmonary diseases were excluded from further analysis. Results The median for forced expiratory volume in 1s (FEV1) was 94.2% and for forced vital capacity (FVC) …
Interval estimation for the breakpoint in segmented regression: a smoothed score-based approach
2017
Summary This paper is concerned with interval estimation for the breakpoint parameter in segmented regression. We present score-type confidence intervals derived from the score statistic itself and from the recently proposed gradient statistic. Due to lack of regularity conditions of the score, non-smoothness and non-monotonicity, naive application of the score-based statistics is unfeasible and we propose to exploit the smoothed score obtained via induced smoothing. We compare our proposals with the traditional methods based on the Wald and the likelihood ratio statistics via simulations and an analysis of a real dataset: results show that the smoothed score-like statistics perform in prac…
A new mathematical approach for the estimation of the AUC and its variability under different experimental designs in preclinical studies
2011
The aim of the present work was to develop a new mathematical method for estimating the area under the curve (AUC) and its variability that could be applied in different preclinical experimental designs and amenable to be implemented in standard calculation worksheets. In order to assess the usefulness of the new approach, different experimental scenarios were studied and the results were compared with those obtained with commonly used software: WinNonlin® and Phoenix WinNonlin®. The results do not show statistical differences among the AUC values obtained by both procedures, but the new method appears to be a better estimator of the AUC standard error, measured as the coverage of 95% confi…
Temporal evolution of some mortality indicators: Application to Spanish data
2012
[EN] In Spain, as in other developed countries, significant changes in mortality patterns have occurred during the 20th and 21st centuries. One reflection of these changes is life expectancy, which has improved in this period, although the robustness of this indicator prevents these changes from being of the same order as those for the probability of death. If, moreover, we bear in mind that life expectancy offers no information as to whether this improvement is the same for different age groups, it is important and necessary to turn to other mortality indicators whose past and future evolution in Spain we are going to study. These indicators are applied to Spanish mortality data for the pe…
Modeling and predicting the Spanish Bachillerato academic results over the next few years using a random network model
2016
[EN] Academic performance is a concern of paramount importance in Spain, where around of 30% of the students in the last two courses in high school, before to access to the labor market or to the university, do not achieve the minimum knowledge required according to the Spanish educational law in force. In order to analyze this problem, we propose a random network model to study the dynamics of the academic performance in Spain. Our approach is based on the idea that both, good and bad study habits, are a mixture of personal decisions and influence of classmates. Moreover, in order to consider the uncertainty in the estimation of model parameters, we perform a lot of simulations taking as t…
Intrinsic credible regions: An objective Bayesian approach to interval estimation
2005
This paper definesintrinsic credible regions, a method to produce objective Bayesian credible regions which only depends on the assumed model and the available data.Lowest posterior loss (LPL) regions are defined as Bayesian credible regions which contain values of minimum posterior expected loss: they depend both on the loss function and on the prior specification. An invariant, information-theory based loss function, theintrinsic discrepancy is argued to be appropriate for scientific communication. Intrinsic credible regions are the lowest posterior loss regions with respect to the intrinsic discrepancy loss and the appropriate reference prior. The proposed procedure is completely general…
A geostatistical approach for dynamic life tables: The effect of mortality on remaining lifetime and annuities
2010
Dynamic life tables arise as an alternative to the standard (static) life table, with the aim of incorporating the evolution of mortality over time. The parametric model introduced by Lee and Carter in 1992 for projected mortality rates in the US is one of the most outstanding and has been used a great deal since then. Different versions of the model have been developed but all of them, together with other parametric models, consider the observed mortality rates as independent observations. This is a difficult hypothesis to justify when looking at the graph of the residuals obtained with any of these methods. Methods of adjustment and prediction based on geostatistical techniques which expl…