48 resultados para modèle causal contrefactuel


Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND There is limited evidence on the optimal timing of antiretroviral therapy (ART) initiation in children 2-5 y of age. We conducted a causal modelling analysis using the International Epidemiologic Databases to Evaluate AIDS-Southern Africa (IeDEA-SA) collaborative dataset to determine the difference in mortality when starting ART in children aged 2-5 y immediately (irrespective of CD4 criteria), as recommended in the World Health Organization (WHO) 2013 guidelines, compared to deferring to lower CD4 thresholds, for example, the WHO 2010 recommended threshold of CD4 count <750 cells/mm(3) or CD4 percentage (CD4%) <25%. METHODS AND FINDINGS ART-naïve children enrolling in HIV care at IeDEA-SA sites who were between 24 and 59 mo of age at first visit and with ≥1 visit prior to ART initiation and ≥1 follow-up visit were included. We estimated mortality for ART initiation at different CD4 thresholds for up to 3 y using g-computation, adjusting for measured time-dependent confounding of CD4 percent, CD4 count, and weight-for-age z-score. Confidence intervals were constructed using bootstrapping. The median (first; third quartile) age at first visit of 2,934 children (51% male) included in the analysis was 3.3 y (2.6; 4.1), with a median (first; third quartile) CD4 count of 592 cells/mm(3) (356; 895) and median (first; third quartile) CD4% of 16% (10%; 23%). The estimated cumulative mortality after 3 y for ART initiation at different CD4 thresholds ranged from 3.4% (95% CI: 2.1-6.5) (no ART) to 2.1% (95% CI: 1.3%-3.5%) (ART irrespective of CD4 value). Estimated mortality was overall higher when initiating ART at lower CD4 values or not at all. There was no mortality difference between starting ART immediately, irrespective of CD4 value, and ART initiation at the WHO 2010 recommended threshold of CD4 count <750 cells/mm(3) or CD4% <25%, with mortality estimates of 2.1% (95% CI: 1.3%-3.5%) and 2.2% (95% CI: 1.4%-3.5%) after 3 y, respectively. The analysis was limited by loss to follow-up and the unavailability of WHO staging data. CONCLUSIONS The results indicate no mortality difference for up to 3 y between ART initiation irrespective of CD4 value and ART initiation at a threshold of CD4 count <750 cells/mm(3) or CD4% <25%, but there are overall higher point estimates for mortality when ART is initiated at lower CD4 values. Please see later in the article for the Editors' Summary.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE To expand the limited information on the prognostic impact of quantitatively obtained collateral function in patients with coronary artery disease (CAD) and to estimate causality of such a relation. DESIGN Prospective cohort study with long-term observation of clinical outcome. SETTING University Hospital. PATIENTS One thousand one hundred and eighty-one patients with chronic stable CAD undergoing 1771 quantitative, coronary pressure-derived collateral flow index measurements, as obtained during a 1-min coronary balloon occlusion (CFI is the ratio between mean distal coronary occlusive pressure and mean aortic pressure both subtracted by central venous pressure). Subgroup of 152 patients included in randomised trials on the longitudinal effect of different arteriogenic protocols on CFI. INTERVENTIONS Collection of long-term follow-up information on clinical outcome. MAIN OUTCOME MEASURES All-cause mortality and major adverse cardiac events. RESULTS Cumulative 15-year survival rate was 48% in patients with CFI<0.25 and 65% in the group with CFI≥0.25 (p=0.0057). Cumulative 10-year survival rate was 75% in patients without arteriogenic therapy and 88% (p=0.0482) in the group with arteriogenic therapy and showing a significant increase in CFI at follow-up. By proportional hazard analysis, the following variables predicted increased all-cause mortality: age, low CFI, left ventricular end-diastolic pressure and number of vessels with CAD. CONCLUSIONS A well-functioning coronary collateral circulation independently predicts lowered mortality in patients with chronic CAD. This relation appears to be causal, because augmented collateral function by arteriogenic therapy is associated with prolonged survival.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The European Water Framework Directive (WFD) requires a status assessment of all water bodies. If that status is deteriorated, the WFD urges the identification of its potential causes in order to be able to suggest appropriate management measures. The instrument of investigative monitoring allows for such identification, provided that appropriate tools are available to link the observed effects to causative stressors, while unravelling confounding factors. In this chapter, the state of the art of status and causal pathway assessment is described for the major stressors responsible for the deterioration of European water bodies, i.e. toxicity, acidification, salinisation, eutrophication and oxygen depletion, parasites and pathogens, invasive alien species, hydromorphological degradation, changing water levels as well as sediments and suspended matter. For each stressor, an extensive description of the potential effects on the ecological status is given. Secondly, stressor-specific abiotic and biotic indicators are described that allow for a first indication of probable causes, based on the assessment of available monitoring data. Subsequently, more advanced tools for site-specific confirmation of stressors at hand are discussed. Finally, the local status assessments are put into the perspective of the risk for downstream stretches in order to be able to prioritise stressors and to be able to select appropriate measures for mitigation of the risks resulting from these stressors.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Les dépressions chroniques sont fréquentes et souvent traitées par des approches traditionnelles. Cet article vise à présenter la nature spécifique de la psychopathologie et un traitement spécifiquement adapté à ces patients avec dépression chronique. Nous décrirons d’abord les spécificités psychopathologiques de cette population, en nous référant aux travaux de J. Piaget et de D. Kiesler. À partir de ces théories, nous mettrons en avant le modèle Cognitive Behavioral Analysis System of Psychotherapy (CBASP), selon McCullough. Cet auteur propose deux volets d’interventions spécifiquement adaptées aux patients avec dépression chronique : l’analyse situationnelle et les techniques interpersonnelles basées sur la notion de transfert et de contre-transfert. Nous soulignerons la pertinence de cette approche par le résumé de plusieurs études empiriques ayant établi l’efficacité de ce modèle, sous certaines conditions cliniques. Nous terminerons par une réflexion de l’application de ce modèle au-delà du tableau clinique de la dépression chronique en ajoutant ainsi des arguments supplémentaires en faveur de l’apport du modèle CBASP au champ actuel de la psychothérapie des troubles mentaux.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

De Mallarmé à la fin du xxe siècle, les œuvres d’avant-garde se situent dans un rapport tensionnel et dialectique à la presse. Jusqu’au surréalisme, la littérature emprunte son modèle à la presse, mais en n’en sélectionnant que certaines caractéristiques, et sans oublier la logique du Livre mallarméen : est ainsi visée une synthèse du livre et du journal, dont Le surréalisme au service de la Révolution constitue l’exemple le plus achevé. Si les œuvres d’assemblage de textes de la deuxième moitié du xxe siècle découlent plutôt du collage, elles intègrent des coupures de presse et permettent non seulement de la critiquer, mais surtout de proposer une « pluritextualité » qui fonctionne autrement que les journaux, et qui pourrait être le modèle d’une presse utopique qui demanderait au lecteur non seulement de s’informer, mais surtout de mettre en relation et en perspective les différentes informations qui lui sont proposées.