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- D’Aeth, Josh C., et al.
(författare)
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Optimal hospital care scheduling during the SARS-CoV-2 pandemic
- 2023
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Ingår i: Management science. - : Institute for Operations Research and the Management Sciences (INFORMS). - 0025-1909 .- 1526-5501. ; 69:10, s. 5695-6415
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Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 pandemic has seen dramatic demand surges for hospital care that have placed a severe strain on health systems worldwide. As a result, policy makers are faced with the challenge of managing scarce hospital capacity to reduce the backlog of non-COVID patients while maintaining the ability to respond to any potential future increases in demand for COVID care. In this paper, we propose a nationwide prioritization scheme that models each individual patient as a dynamic program whose states encode the patient’s health and treatment condition, whose actions describe the available treatment options, whose transition probabilities characterize the stochastic evolution of the patient’s health, and whose rewards encode the contribution to the overall objectives of the health system. The individual patients’ dynamic programs are coupled through constraints on the available resources, such as hospital beds, doctors, and nurses. We show that the overall problem can be modeled as a grouped weakly coupled dynamic program for which we determine near-optimal solutions through a fluid approximation. Our case study for the National Health Service in England shows how years of life can be gained by prioritizing specific disease types over COVID patients, such as injury and poisoning, diseases of the respiratory system, diseases of the circulatory system, diseases of the digestive system, and cancer.
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| 2. |
- D’Aeth, Josh C., et al.
(författare)
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Optimal national prioritization policies for hospital care during the SARS-CoV-2 pandemic
- 2021
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Ingår i: Nature Computational Science. - : Springer Nature. - 2662-8457. ; 1:8, s. 521-531
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Tidskriftsartikel (refereegranskat)abstract
- In response to unprecedented surges in the demand for hospital care during the SARS-CoV-2 pandemic, health systems have prioritized patients with COVID-19 to life-saving hospital care to the detriment of other patients. In contrast to these ad hoc policies, we develop a linear programming framework to optimally schedule elective procedures and allocate hospital beds among all planned and emergency patients to minimize years of life lost. Leveraging a large dataset of administrative patient medical records, we apply our framework to the National Health Service in England and show that an extra 50,750–5,891,608 years of life can be gained compared with prioritization policies that reflect those implemented during the pandemic. Notable health gains are observed for neoplasms, diseases of the digestive system, and injuries and poisoning. Our open-source framework provides a computationally efficient approximation of a large-scale discrete optimization problem that can be applied globally to support national-level care prioritization policies.
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| 3. |
- Weinbruch, Stephan, et al.
(författare)
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Chemical composition and sources of aerosol particles at Zeppelin Mountain (Ny Alesund, Svalbard) : An electron microscopy study
- 2012
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 49, s. 142-150
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Tidskriftsartikel (refereegranskat)abstract
- Aerosol particles were collected at the Zeppelin Mountain Atmospheric Research Station (474 m asl) near Ny Alesund (Svalbard, Norway) on 27 different days between July 2007 and December 2008. The size, morphology and chemical composition of 57,617 individual particles were studied by high-resolution scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on chemical composition, morphology, mixing state and stability under electron bombardment, the particles were assigned to one of the following groups: sea salt, aged sea salt, Ca sulphates, Na sulphates, carbonates, soot, silicates, fly ashes, secondary aerosol, secondary aerosol plus sodium, secondary aerosol plus soot, mixed particles and others. Sea salt, aged sea salt, silicates and mixed particles (mixtures of sea salt, silicates and Ca sulphates) are the most abundant groups for particles with aerodynamic diameters > 0.5 mu m, secondary aerosol, mixed particles and secondary aerosol with soot inclusions below 0.5 mu m. Silicate fly ashes (major source coal burning) and metal fly ashes (from metallurgical high temperature processes) occur only at very low number concentrations. In contrast to previous work, the fly ash abundance is not correlated with air masses that crossed industrialized regions in Central and Eastern Europe, Scandinavia or Russia. These observations indicate a significant reduction of long-range transport of heavy metals to Svalbard. Soot (external and internally mixed with secondary aerosol) shows a pronounced seasonal pattern with a much lower abundance during summer compared to spring, autumn and winter. The soot abundance is not correlated with the air mass back-trajectories. During summer (July and August), soot was only observed when cruise ships were present in the area around Ny Alesund (Kongsfjorden). Pronounced seasonal patterns were observed for the abundance of the mineral dust component which is generally lower in summer compared to the other seasons. The observed seasonal dependence of anthropogenic primary particles (soot, fly ashes) is in good agreement with the Arctic circulation pattern.
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