The Impact of Pooling on Throughput Time in Discretionary Work Settings: An Empirical Investigation of Emergency Department Length of Stay

We conduct an empirical investigation on the impact of pooling tasks and resources on throughput times in a discretionary work setting. We use an Emergency Department’s (ED) patient-level data (N = 234,334) from 2007 to 2010 to test our hypotheses. We find that when the ED’s work system had pooled tasks and resources, patients’ lengths of stay were longer than when the ED converted to having dedicated tasks and resources. More specifically, we find that dedicated systems resulted in a 9 percent overall decrease in length of stay, which corresponds to a 25-minute reduction in length of stay for an average patient of medium severity in this ED. We propose that the improved performance comes from a reduction in social loafing and a more distributed utilization of shared resources. These benefits outweigh the expected efficiency gains from pooling, which are commonly predicted by queuing theory

The Diseconomies of Queue Pooling: An Empirical Investigation of Emergency Department Length of Stay

We conduct an empirical investigation of the impact of two different queue management systems on throughput times. Using an Emergency Department’s (ED) patient-level data (N = 231,081) from 2007 to 2010, we find that patients’ lengths of stay (LOS) were longer when physicians were assigned patients under a pooled queuing system, compared to when each physician operated under a dedicated queuing system. The dedicated queuing system resulted in a 10 percent decrease in LOS—a 32-minute reduction in LOS for an average patient of medium severity in this ED. We propose that the dedicated queuing system yielded shorter throughput times because it provided physicians with greater ability and incentive to manage their patients’ flow through the ED from arrival to discharge. Consistent with social loafing theory, our analysis shows that patients were treated and discharged at a faster rate in the dedicated queuing system than in the pooled queuing system. We conduct additional analyses to rule out alternate explanations, such as stinting on care and decreased quality of care. Our paper has implications for health care organizations and others seeking to reduce throughput time, resource utilization, and costs

Sleep Education for Elders Program (SLEEP): Promising Pilot Results of a Virtual, Health Educator-Led, Community-Delivered Sleep Behavior Change Intervention

Purpose: Sleep problems pose serious public health concerns, and evidence suggests that the problem is worsening. Both sufficient sleep quantity and quality are needed for optimal health, particularly among older adults, but access to sleep care can be difficult. This study examined the efficacy of a six-week sleep behavior change program designed for older adults that was delivered virtually by health educators. Participants and Methods: This quasi-experimental pilot study (intervention n = 22; control n = 31) explored the effects of the Sleep Education for Elders Program (SLEEP) on sleep outcomes, which included: 1) sleep quality, measured by the Pittsburgh Sleep Quality Index (PSQI); 2) sleep duration, extracted from the PSQI; 3) insomnia symptoms, measured by the Insomnia Severity Index; 4) sleep hygiene behaviors, obtained from the Sleep Hygiene Index; and 5) excessive daytime sleepiness, measured by the Epworth Sleepiness Scale. Results: After SLEEP, the intervention group experienced significantly improved sleep quality (p \u3c 0.001), a reduction in maladaptive sleep hygiene behaviors (p = 0.007), and reduced daytime sleepiness (p \u3c 0.027) compared to the control group. Effect sizes for all five sleep measures were medium or large. In the intervention group, all changes were judged to be clinically meaningful (≥ 0.5 SD) except for improvements in daytime sleepiness. Conclusion: These data support the efficacy of a group-based, virtual behavior change intervention in improving sleep outcomes among older adults

Stockpiling medicines at the onset of the COVID-19 pandemic: an empirical analysis of national prescription drug sales and prices

Hospitals with Coronavirus disease (COVID-19) demand surges at the onset of the pandemic report medication shortages, a worrisome phenomenon as inadequate medication supplies negatively affect patient outcomes. The popular press implicates a lack of raw ingredients and spikes in purchases but rigorous research is needed to more accurately identify shortage causes. We leverage a quasi-experimental design on IQVIA’s National Sales Perspectives™ data from 2018-2020 with a focus on medicines related to U.S. hospital-based COVID-19 treatment and a set of control medicines not used for COVID-19. We contribute to supply chain theory by empirically demonstrating that stockpiling among U.S. medical providers in the early phase of the pandemic accounts for the shortages. The buyers’ behavior results in concentration of the sales volume of COVID-19 medicines in the first two months of the pandemic. After these first two months, the sales volume of drugs for COVID-19 treatment decreases significantly despite a nationwide increase in COVID-19-related hospitalizations. An implication for manufacturers is that orders due to stockpiling by downstream buyers early on in a pandemic period should be discounted when predicting future demand. We also investigate another potential cause: expected price increases in the future. Counter to concerns that drug manufacturers would engage in price gouging behavior, we find no evidence of price inflation for these drugs. Our results are robust to numerous sensitivity checks and have implications for manufacturers, hospitals, and policymakers that may improve medicine supply resiliency against future threats.https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3988183First author draf

High-Pressure Transformation of SiO2 Glass from a Tetrahedral to an Octahedral Network:A Joint Approach Using Neutron Diffraction and Molecular Dynamics

International audienceA combination of in situ high-pressure neutron diffraction at pressures up to 17.5(5) GPa and moleculardynamics simulations employing a many-body interatomic potential model is used to investigate thestructure of cold-compressed silica glass. The simulations give a good account of the neutron diffractionresults and of existing x-ray diffraction results at pressures up to ∼60 GPa. On the basis of the moleculardynamics results, an atomistic model for densification is proposed in which rings are “zipped” by a pairingof five- and/or sixfold coordinated Si sites. The model gives an accurate description for the dependence ofthe mean primitive ring size hni on the mean Si-O coordination number, thereby linking a parameter that issensitive to ordering on multiple length scales to a readily measurable parameter that describes the localcoordination environment

Impact of changing climate on bryophyte contributions to terrestrial water, carbon, and nitrogen cycles

Bryophytes, including the lineages of mosses, liverworts, and hornworts, are the second-largest photoautotroph group on Earth. Recent work across terrestrial ecosystems has highlighted how bryophytes retain and control water, fix substantial amounts of carbon (C), and contribute to nitrogen (N) cycles in forests (boreal, temperate, and tropical), tundra, peatlands, grasslands, and deserts. Understanding how changing climate affects bryophyte contributions to global cycles in different ecosystems is of primary importance. However, because of their small physical size, bryophytes have been largely ignored in research on water, C, and N cycles at global scales. Here, we review the literature on how bryophytes influence global biogeochemical cycles, and we highlight that while some aspects of global change represent critical tipping points for survival, bryophytes may also buffer many ecosystems from change due to their capacity for water, C, and N uptake and storage. However, as the thresholds of resistance of bryophytes to temperature and precipitation regime changes are mostly unknown, it is challenging to predict how long this buffering capacity will remain functional. Furthermore, as ecosystems shift their global distribution in response to changing climate, the size of different bryophyte-influenced biomes will change, resulting in shifts in the magnitude of bryophyte impacts on global ecosystem functions

Density-driven structural transformations in B2O3 glass

The method of in situ high-pressure neutron diffraction is used to investigate the structure of B2O3 glass on compression in the range from ambient to 17.5(5) GPa. The experimental results are supplemented by molecular dynamics simulations made using a newly developed aspherical ion model. The results tie together those obtained from other experimental techniques to reveal three densification regimes. In the first, BO3 triangles are the predominant structural motifs as the pressure is increased from ambient to 6.3(5) GPa, but there is an alteration to the intermediate range order which is associated with the dissolution of boroxol rings. In the second, BO4 motifs replace BO3 triangles at pressures beyond 6.3 GPa and the dissolution of boroxol rings continues until it is completed at 11–14 GPa. In the third, the B-O coordination number continues to increase with pressure to give a predominantly tetrahedral glass, a process that is completed at a pressure in excess of 22.5 GPa. On recovery of the glass to ambient from a pressure of 8.2 GPa, triangular BO3 motifs are recovered but, relative to the uncompressed material, there is a change to the intermediate range order. The comparison between experiment and simulation shows that the aspherical ion model is able to provide results of unprecedented accuracy at pressures up to at least 10 GPa

Density-driven defect-mediated network collapse of GeSe2 glass

International audienceThe evolution in structure of the prototypical network-forming glass GeSe2 is investigated at pressures up to∼16 GPa by using a combination of neutron diffraction and first-principles molecular dynamics. The neutrondiffraction work at pressures8.2 GPa employed themethod of isotope substitution, and the molecular dynamicssimulations were performed with two different exchange-correlation functionals, the Becke-Lee-Yang-Parr(BLYP) and the hybrid Heyd-Scuseria-Ernzerhof HSE06. The results show density-driven structural transformationsthat differ substantially from those observed in common oxide glasses such as SiO2 and GeO2. Edge-sharingtetrahedra persist as important structural motifs until a threshold pressure of∼8.5GPa is attained,whereupon amediatingrole is found for homopolar bonds in the appearance of higher coordinated Ge-centered polyhedra. Thesemechanisms of network transformation are likely to be generic for the class of glass-forming materials wherehomopolar bonds and fragility-promoting edge-sharing motifs are prevalent in the ambient-pressure networ

BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers

Background: The K3326X variant in BRCA2 (BRCA2*c.9976A>T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers. Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided. Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed. Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy