91 research outputs found
Risk factors for severe COVID-19 disease and death in patients aged 70 and over: a retrospective observational cohort study
No full textOBJECTIVES: The COVID-19 pandemic resulted in rapid reorganisations of hospital care. In our hospital, the geriatrics team introduced the Clinical Frailty Scale (CFS) on the non-ICU COVID-19 units during these reorganisations. A retrospective analysis was performed to investigate the CFS as a risk factor for severe COVID-19 disease and in-hospital death in older patients with COVID-19. METHODS: In patients aged ≥70 years, an online geriatric assessment questionnaire was launched, from which the CFS was scored by the geriatrics team. Additional clinical data were collected from the electronic medical records. Risk factors related to ageing, such as the CFS, age-adjusted Charlson Comorbidity Index, living situation and cognitive decline, were examined alongside frequently reported risk factors in the general population. Outcomes were in-hospital death (primary outcome) and oxygen need of ≥6 litres and early warning score ≥7, as parameters for severe disease (secondary outcomes). Baseline characteristics were described with descriptive statistics. Associations were analysed with uni- and multivariable analyses. RESULTS: One hundred and five patients were included, median age 82 years. CFS scores were 1-4 in 43, 5-6 in 45, and 7-9 in 17 patients. In multivariable analysis, CFS and cognitive decline were the only risk factors that were independently associated with in-hospital mortality. Chronic obstructive pulmonary disease, presence of respiratory symptoms on admission and male gender showed and independent association with severe disease. CONCLUSION: A retrospective analysis shows that CFS and cognitive decline have added value for predicting in-hospital mortality in older patients with COVID-19 disease.sponsorship: fundingstatus: Publishe
Care for older persons on the emergency department: does a transitional geriatric care model (URGENT care model) prevent unplanned emergency department readmissions?
No full textTighter spectral bounds for the cut size, based on Laplacian eigenvectors
No full textThe cut-set ∂V in a graph is defined as the set of all links between a set of nodes V and all other nodes in that graph. Finding bounds for the size of a cut-set |∂V| is an important problem, and is related to mixing times, connectedness and spreading processes on networks. A standard way to bound the number of links in a cut-set |∂V| relies on Laplacian eigenvalues, which approximate the largest and smallest possible cut-sets for a given size of the set V. In this article, we extend the standard spectral approximations by including information about the Laplacian eigenvectors. This additional information leads to provably tighter bounds compared to the standard spectral bounds. We apply our new method to find improved spectral bounds for the well-known Cheeger constant, the Max Cut problem and the expander mixing lemma. We also apply our bounds to study cut sizes in the hypercube graph, and describe an application related to the spreading of epidemics on networks. We further illustrate the performance of our new bounds using simulations, revealing that a significant improvement over the standard bounds is possible.Accepted author manuscriptNetwork Architectures and Service
Structure and dynamics of complex networks: Network epidemics and a geometric robustness measure
No full textAs new technologies continue to find their way into everyday life, the world becomes more and more connected. Airplanes and other means of transportation provide global connections in the physical world, while the omnipresence of the Internet means that information is shared around the globe, easier than ever before. But not only these man-made systems aredistinctly connected, other complex systems like the human brain, or metabolic networks are successfully being studied from the perspective of their constituting connections. The combining concept in all these examples is the structure of the problem at hand: each system consists of interacting elementary components at the lowest level, from which a network structure emerges at the global level. The study of such networked systems, their observed features and the wide range of related analysis tools is commonly referred to as NetworkScience.In this thesis, the specific problem of how diseases spread over networks is addressed. Better understanding this spreading behavior has significant practical importance, i.e. for the prediction and control of disease prevalence, and poses many interesting theoretical challenges. In the context of modeling epidemics on networks, we formulate the Universal Mean-Field Framework. This new and theoretically well-founded framework unifies and generalizes a number of existing approximate models, and brings forth new approaches to bound the approximations. Apart from the work on epidemics, some new insights are explored in the context of the connections between electrical circuits, networks and simplices (higher-dimensional triangles). These deep theoretical equivalences allow the tools and intuitions from electrical circuits and geometry to be used in the study of networks. A comprehensive introduction and discussion of the equivalent representations and their connections is given. Additionally, we derive a new formula for the volume of a hyperacute simplex and propose to use this volume as a network-robustness measure
[The development and validation of a standardised transfer sheet for care transitions between residential and acute care settings in Leuven, Belgium]
No full textWhen elderly patients are transferred from a residential to an acute care setting, important information regarding their health care can be lost. Over the past years, the concept of advance care planning has also been given a more prominent place in the care for the elderly. However it remains a challenge to communicate the results achieved by this process when patients are referred to another health care setting. Developing a sound method for transferring information is a key element in the transitional care for the elderly patient.status: Publishe
Structure and processes of emergency observation units with a geriatric focus: a scoping review
No full textBACKGROUND: Combining observation principles and geriatric care concepts is considered a promising strategy for risk-stratification of older patients with emergency care needs. We aimed to map the structure and processes of emergency observation units (EOUs) with a geriatric focus and explore to what extent the comprehensive geriatric assessment (CGA) approach was implemented in EOUs. METHODS: The revised scoping methodology framework of Arksey and O'Malley was applied. Manuscripts reporting on dedicated areas within hospitals for observation of older patients with emergency care needs were eligible for inclusion. Electronic database searches were performed in MEDLINE, EMBASE and CINAHL in combination with backward snowballing. Two researchers conducted data charting independently. Data-charting forms were developed and iteratively refined. Data inconsistencies were judged by a third researcher or discussed in the research team. Quality assessment was conducted with the Methodological Index for Non-Randomized Studies. RESULTS: Sixteen quantitative studies were included reporting on fifteen EOUs in seven countries across three continents. These units were located in the ED, immediately next to the ED or remote from the ED (i.e. hospital-based). All studies reported that staffing consisted of at least three healthcare professions. Observation duration varied between 4 and 72 h. Most studies focused on medical and functional assessment. Four studies reported to assess a patients' medical, functional, cognitive and social capabilities. If deemed necessary, post-discharge follow-up (e.g. community/primary care services and/or outpatient clinics) was provided in eleven studies. CONCLUSION: This scoping review documented that the structure and processes of EOUs with a geriatric focus are very heterogeneous and rarely cover all elements of CGA. Further research is necessary to determine how complex care principles of 'observation medicine' and 'CGA' can ideally be merged and successfully implemented in clinical care.sponsorship: The authors did not receive grants, institutional or corporate support to conduct this study. PH is holder of a PhD fellowship granted by Research Foundation -Flanders (FWO) (1133320 N). (Research Foundation -Flanders (FWO)|1133320 N)status: Publishe
Environment and self-regulation in galaxy formation
No full textThe environment is known to affect the formation and evolution of galaxies considerably best visible through the well-known morphology–density relationship. It is less clear, though, whether the environment is equally important at a given galaxy morphology. In this paper, we study the effect of environment on the evolution of early-type galaxies as imprinted in the fossil record by analysing the stellar population properties of 3360 galaxies morphologically selected by visual inspection from the Sloan Digital Sky Survey in a narrow redshift range ( 0.05 ≤z≤ 0.06 ). The morphological selection algorithm is critical, as it does not bias against recent star formation. We find that the distribution of ages is bimodal with a strong peak at old ages and a secondary peak at young ages around ∼2.5 Gyr containing about 10 per cent of the objects. This is an analogue to 'red sequence' and 'blue cloud' identified in galaxy populations usually containing both early- and late-type galaxies. The fraction of the young, rejuvenated galaxies increases with both decreasing galaxy mass and decreasing environmental density up to about 45 per cent, which implies that the impact of environment increases with decreasing galaxy mass. The rejuvenated galaxies have lower α/Fe ratios than the average and most of them show signs of ongoing star formation through their emission line spectra. All objects that host active galactic nuclei in their centres without star formation are part of the red sequence population. We confirm and statistically strengthen earlier results that luminosity weighted ages, metallicities and α/Fe element ratios of the red sequence population correlate well with velocity dispersion and galaxy mass. Most interestingly, however, these scaling relations are not sensitive to environmental densities and are only driven by galaxy mass. We infer that early-type galaxy formation has undergone a phase transition a few billion years ago around z∼ 0.2 . A self-regulated formation phase without environmental dependence has recently been superseded by a rejuvenation phase, in which the environment plays a decisive role possibly through galaxy mergers and interactions
Unified mean-field framework for susceptible-infected-susceptible epidemics on networks, based on graph partitioning and the isoperimetric inequality
No full textWe propose an approximation framework that unifies and generalizes a number of existing mean-field approximation methods for the susceptible-infected-susceptible (SIS) epidemic model on complex networks. We derive the framework, which we call the unified mean-field framework (UMFF), as a set of approximations of the exact Markovian SIS equations. Our main novelty is that we describe the mean-field approximations from the perspective of the isoperimetric problem, which results in bounds on the UMFF approximation error. These new bounds provide insight in the accuracy of existing mean-field methods, such as the N-intertwined mean-field approximation and heterogeneous mean-field method, which are contained by UMFF. Additionally, the isoperimetric inequality relates the UMFF approximation accuracy to the regularity notions of Szemerédi's regularity lemma.Network Architectures and Service
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