Length of Stay and Home Discharge for Patients with Inpatient Stroke Rehabilitation.

OBJECTIVE: To examine temporal trends and geographic variations and predict inpatient rehabilitation (IPR) length of stay (LOS) and home discharge for stroke patients. METHODS: Patients aged ≥18 years who were admitted to an IPR facility in Alberta, Canada, between 04/2014 and 03/2018 (years 2014-2017) were included. Predictors of LOS and home discharge were examined using 2014-2016 data and validated using 2017 data. Multivariable linear regression (MLR), multivariable negative binomial (MNB), and multivariable quantile regressions (MQR) were used to examine LOS, and logistic regression was used for home discharge. RESULTS: We included 2686 rehabilitation admissions between 2014 and 2017. The mean LOS decreased (2014: 71 days; 2017: 62.1 days; p = 0.003) during the study period and was shortest in Edmonton (59.1 days) compared to Calgary (66 days) or other localities (70.8 days; p < 0.001). Three-quarters of patients were discharged home and this proportion remained unchanged between 2014 and 2017. Calgary patients were more likely to be discharged home than those in Edmonton (OR = 0.62; p = 0.019) or other localities (OR = 0.39; p = 0.011). The MLR and MNB models provided accurate prediction for the mean LOS (predicted = 59.9 and 60.8 days, respectively, vs. actual = 62.1 days; both p > 0.5), while the MQR model did so for the median LOS (predicted = 44.3 days vs. actual = 44 days; p = 0.09). The logistic regression resulted in 82.4% of correct prediction, a sensitivity of 91.6%, and a specificity of 50.7% for home discharge. CONCLUSIONS: Rehabilitation LOS decreased while the proportion of home discharge remained unchanged during the study period. Both varied across health zones. Identifiable statistical models provided accurate prediction with a separate patient cohort.

Fast Li-Ion Conduction in Spinel-Structured Solids.

Spinel-structured solids were studied to understand if fast Li+ ion conduction can be achieved with Li occupying multiple crystallographic sites of the structure to form a "Li-stuffed" spinel, and if the concept is applicable to prepare a high mixed electronic-ionic conductive, electrochemically active solid solution of the Li+ stuffed spinel with spinel-structured Li-ion battery electrodes. This could enable a single-phase fully solid electrode eliminating multi-phase interface incompatibility and impedance commonly observed in multi-phase solid electrolyte-cathode composites. Materials of composition Li1.25M(III)0.25TiO4, M(III) = Cr or Al were prepared through solid-state methods. The room-temperature bulk Li+-ion conductivity is 1.63 × 10-4 S cm-1 for the composition Li1.25Cr0.25Ti1.5O4. Addition of Li3BO3 (LBO) increases ionic and electronic conductivity reaching a bulk Li+ ion conductivity averaging 6.8 × 10-4 S cm-1, a total Li-ion conductivity averaging 4.2 × 10-4 S cm-1, and electronic conductivity averaging 3.8 × 10-4 S cm-1 for the composition Li1.25Cr0.25Ti1.5O4 with 1 wt. % LBO. An electrochemically active solid solution of Li1.25Cr0.25Mn1.5O4 and LiNi0.5Mn1.5O4 was prepared. This work proves that Li-stuffed spinels can achieve fast Li-ion conduction and that the concept is potentially useful to enable a single-phase fully solid electrode without interphase impedance.

Origin of High Activity and Durability of Twisty Nanowire Alloy Catalysts under Oxygen Reduction and Fuel Cell Operating Conditions.

The ability to control the surface composition and morphology of alloy catalysts is critical for achieving high activity and durability of catalysts for oxygen reduction reaction (ORR) and fuel cells. This report describes an efficient surfactant-free synthesis route for producing a twisty nanowire (TNW) shaped platinum-iron (PtFe) alloy catalyst (denoted as PtFe TNWs) with controllable bimetallic compositions. PtFe TNWs with an optimal initial composition of ∼24% Pt are shown to exhibit the highest mass activity (3.4 A/mgPt, ∼20 times higher than that of commercial Pt catalyst) and the highest durability (<2% loss of activity after 40 000 cycles and <30% loss after 120 000 cycles) among all PtFe-based nanocatalysts under ORR or fuel cell operating conditions reported so far. Using ex situ and in situ synchrotron X-ray diffraction coupled with atomic pair distribution function (PDF) analysis and 3D modeling, the PtFe TNWs are shown to exhibit mixed face-centered cubic (fcc)-body-centered cubic (bcc) alloy structure and a significant lattice strain. A striking finding is that the activity strongly depends on the composition of the as-synthesized catalysts and this dependence remains unchanged despite the evolution of the composition of the different catalysts and their lattice constants under ORR or fuel cell operating conditions. Notably, dealloying under fuel cell operating condition starts at phase-segregated domain sites leading to a final fcc alloy structure with subtle differences in surface morphology. Due to a subsequent realloying and the morphology of TNWs, the surface lattice strain observed with the as-synthesized catalysts is largely preserved. This strain and the particular facets exhibited by the TNWs are believed to be responsible for the observed activity and durability enhancements. These findings provide new insights into the correlation between the structure, activity, and durability of nanoalloy catalysts and are expected to energize the ongoing effort to develop highly active and durable low-Pt-content nanowire catalysts by controlling their alloy structure and morphology.

Publicly funded clinical research in Canada.

Clinical research is funded by industry, governments, charities, and hospitals. It is important to know the economic commitment of the various funding bodies, but until now there has been no national source available which provides these data. We surveyed the major funders to provide such a measure. There is evidence that government and charity funding of medical research is a trigger for private sector research investment; therefore, tracking all sources of funding for clinical research will provide policy-makers with an overall picture of health research funding. These data support policy decision-making related to clinical research in Canada.

The high cost of critical care unit over-utilization for patients with NSTE ACS.

BACKGROUND: There is substantial variability among hospitals in critical care unit (CCU) utilization for patients admitted with non-ST-Segment Elevation Acute Coronary Syndromes (NSTE ACS). We estimated the potential cost saving if all hospitals adopted low CCU utilization practices for patients with NSTE ACS. METHODS: National hospital claims data were used to identify all patients with a primary diagnosis of NSTE ACS initially admitted to an acute care hospital between 2007 and 2013. Hospital CCU utilization was classified as low (<30%), medium (30-70%), or high (>70%). RESULTS: Among the 270,564 NSTE ACS hospitalizations (71.6% non-ST-segment elevation myocardial infarction; 28.4% unstable angina) admitted to 261 hospitals, 41.9% (inter-hospital range 0.3%-95.1%) were admitted to a CCU. The proportion of patients admitted to a CCU in low, medium and high utilization hospitals was 16.3%, 49.5%, and high 81.1%, respectively. No differences in adjusted inpatient mortality were observed by hospital CCU utilization. The overall inpatient costs of caring for NSTE ACS were $1.1 billion. CCU care accounted for 45.2% of all hospitalization costs including 22.6%, 49.9%, and 69.0% (P < .001) of costs in low, medium and high utilization centers. The national potential direct cost savings of medium and high CCU utilization centers adopting low NSTE ACS CCU utilization practices was $113.4 million over the study period. CONCLUSIONS: In a population-based contemporary cohort, CCU utilization for patients with NSTE ACS varied widely and in-hospital mortality was similar between low, medium and high utilization centers. CCU care accounted for 45% of hospitalization costs; thus, implementing policies and admission practices to align hospital resources with patient care needs have the potential to reduce overall health care costs.

The Economic Contribution of Industry-Sponsored Pharmaceutical Clinical Trials.

PURPOSE: In pharmaceutical clinical trials, industrial sponsors pay for study drugs and related healthcare services. We conducted a study to determine industry's economic contribution of these trials to the Alberta healthcare system.  Methods: We used data from two trial centers for cancer and non-cancer trials at the University of Alberta. For each trial (cancer, non-cancer), we calculated the cost of drugs provided by the sponsors using the market price, the cost of clinical services, and the cost of administrative services that they paid. We extrapolated these results to all trials in Alberta based on information obtained from the registration website ClinicalTrials.gov.  Results: Our sample consisted of 40 non-cancer and 39 cancer drug trials which were initiated in 2012. The monetary value of the industry sponsors' contribution was $799,055 per non-cancer and $630,243 per cancer drug trial. Drugs (in-trial and post-trial) accounted for 84% of the total contribution of the non-cancer drug trials whereas it represented 93% of all trial-related contributions in the cancer category. The total province-wide contribution of industry-sponsored drug trials which were initiated in 2012 was estimated to be $101 million, including open-label drugs in the non-cancer category.  Conclusions: Industry-sponsored pharmaceutical trials represent a major economic contributor to clinical research within the province.

Utilization of early supported discharge and outpatient rehabilitation services following inpatient stroke rehabilitation.

BACKGROUND: Studies examining factors associated with patient referral to early supported discharge (ESD)/outpatient rehabilitation (OPR) programs and utilization of ESD/OPR services after discharge from inpatient stroke rehabilitation (IPR) are scarce. Accordingly, we examined utilization of ESD/OPR services following discharge from IPR and patient factors associated with service utilization. METHODS: Stroke patients discharged from IPR facilities in Alberta between April 2014 and March 2016 were included and followed for one year for ESD/OPR service utilization. Multivariable linear and negative binomial regressions were used to examine association of patients' factors with ESD/OPR use. RESULTS: We included 752 patients (34.4% of 2,187 patients discharged from IPR) who had 40,772 ESD/OPR visits during one year of follow-up in the analysis. Mean and median ESD/OPR visits were 54.2 and 36 visits, respectively. Unadjusted ESD/OPR visits were lower in females and patients aged ≥ 60 years but were similar between urban and rural areas. After adjustment for patient factors, patients in urban areas and discharged home after IPR were associated with 83.5% and 61.9%, respectively, increase in ESD/OPR visits, while having a right-body stroke was associated with 23.5% increase. Older patients used ESD/OPR less than their younger counterparts (1.4% decrease per one year of older age). Available factors explained 12.3% of variation in ESD/OPR use. CONCLUSION: ESD/OPR utilization after IPR in Alberta was low and varied across age and geographic locations. Factors associated with use of ESD/OPR were identified but they could not fully explain variation of ESD/OPR use.

Bipartite invariance in mouse primary visual cortex.

A defining characteristic of intelligent systems, whether natural or artificial, is the ability to generalize and infer behaviorally relevant latent causes from high-dimensional sensory input, despite significant variations in the environment. To understand how brains achieve generalization, it is crucial to identify the features to which neurons respond selectively and invariantly. However, the high-dimensional nature of visual inputs, the non-linearity of information processing in the brain, and limited experimental time make it challenging to systematically characterize neuronal tuning and invariances, especially for natural stimuli. Here, we extended "inception loops" - a paradigm that iterates between large-scale recordings, neural predictive models, and in silico experiments followed by in vivo verification - to systematically characterize single neuron invariances in the mouse primary visual cortex. Using the predictive model we synthesized Diverse Exciting Inputs (DEIs), a set of inputs that differ substantially from each other while each driving a target neuron strongly, and verified these DEIs' efficacy in vivo. We discovered a novel bipartite invariance: one portion of the receptive field encoded phase-invariant texture-like patterns, while the other portion encoded a fixed spatial pattern. Our analysis revealed that the division between the fixed and invariant portions of the receptive fields aligns with object boundaries defined by spatial frequency differences present in highly activating natural images. These findings suggest that bipartite invariance might play a role in segmentation by detecting texture-defined object boundaries, independent of the phase of the texture. We also replicated these bipartite DEIs in the functional connectomics MICrONs data set, which opens the way towards a circuit-level mechanistic understanding of this novel type of invariance. Our study demonstrates the power of using a data-driven deep learning approach to systematically characterize neuronal invariances. By applying this method across the visual hierarchy, cell types, and sensory modalities, we can decipher how latent variables are robustly extracted from natural scenes, leading to a deeper understanding of generalization.

Pattern completion and disruption characterize contextual modulation in mouse visual cortex.

A key role of sensory processing is integrating information across space. Neuronal responses in the visual system are influenced by both local features in the receptive field center and contextual information from the surround. While center-surround interactions have been extensively studied using simple stimuli like gratings, investigating these interactions with more complex, ecologically-relevant stimuli is challenging due to the high dimensionality of the stimulus space. We used large-scale neuronal recordings in mouse primary visual cortex to train convolutional neural network (CNN) models that accurately predicted center-surround interactions for natural stimuli. These models enabled us to synthesize surround stimuli that strongly suppressed or enhanced neuronal responses to the optimal center stimulus, as confirmed by in vivo experiments. In contrast to the common notion that congruent center and surround stimuli are suppressive, we found that excitatory surrounds appeared to complete spatial patterns in the center, while inhibitory surrounds disrupted them. We quantified this effect by demonstrating that CNN-optimized excitatory surround images have strong similarity in neuronal response space with surround images generated by extrapolating the statistical properties of the center, and with patches of natural scenes, which are known to exhibit high spatial correlations. Our findings cannot be explained by theories like redundancy reduction or predictive coding previously linked to contextual modulation in visual cortex. Instead, we demonstrated that a hierarchical probabilistic model incorporating Bayesian inference, and modulating neuronal responses based on prior knowledge of natural scene statistics, can explain our empirical results. We replicated these center-surround effects in the multi-area functional connectomics MICrONS dataset using natural movies as visual stimuli, which opens the way towards understanding circuit level mechanism, such as the contributions of lateral and feedback recurrent connections. Our data-driven modeling approach provides a new understanding of the role of contextual interactions in sensory processing and can be adapted across brain areas, sensory modalities, and species.

Economic impact of self-administered subcutaneous versus clinic-administered intravenous immunoglobulin G therapy in Alberta, Canada: a population-based cohort study.

BACKGROUND: Self-administered subcutaneous immunoglobulin G (SCIg) reduces nursing time and eliminates the need for treatment at ambulatory care clinics, as compared with clinic-based intravenously administered IgG (IVIg), and are therapeutically equivalent. Estimating the economic impact of self-administered SCIg versus clinic-administered IVIg therapy may guide treatment recommendations. METHODS: A retrospective population-based cohort study using administrative data from Alberta was performed; those treated with IgG between April 1, 2012 and March 31, 2019 were included. Costs for medical laboratory staff and nursing time, as well as ambulatory care visits were considered. Univariate generalized linear model regression with gamma distribution and log link was used to compare cost ($CDN 2020) between SCIg and IVIg administration. Stratified analysis by age (≥ 18-years; < 18-years) was performed. RESULTS: Among 7,890 (6,148 adults; 1,742 children) individuals who received IgG, the average administration cost per patient-year of self-administered SCIg was $5,386 (95% confidence interval [CI] $5,039, $5,734) lower than clinic-administered IVIg; per patient-year cost of self-administered SCIg was $817 (95% CI $723, $912) versus $6,204 (95% CI $6,100, $6,308) for clinic-administered IVIg. The per patient-year cost of self-administered SCIg was $5,931 (95% CI $5,543, $6,319) lower among adults and $3,177 (95% CI $2,473, $3,882) lower among children compared with clinic-administered IVIg. An estimated $31.0 million (95% CI $29.0, $33.0) in cost savings to the health system would be realised if 80% of individuals switched from clinic-administered IVIg to self-administered SCIg. CONCLUSIONS: Self-administered SCIg is substantially less costly from a health care payer perspective in Canada. Within this type of health system, switching to self-administered SCIg has the potential to reduce overall health care costs, lessen nursing burden, and may increase clinic-based capacity for others.

Lattice Strain and Surface Activity of Ternary Nanoalloys under the Propane Oxidation Condition.

The ability to harness the catalytic oxidation of hydrocarbons is critical for both clean energy production and air pollutant elimination, which requires a detailed understanding of the dynamic role of the nanophase structure and surface reactivity under the reaction conditions. We report here findings of an in situ/operando study of such details of a ternary nanoalloy under the propane oxidation condition using high-energy synchrotron X-ray diffraction coupled to atomic pair distribution function (HE-XRD/PDF) analysis and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The catalysts are derived by alloying Pt with different combinations of second (Pd) and third (Ni) transition metals, showing a strong dependence of the catalytic activity on the Ni content. The evolution of the phase structure of the nanoalloy is characterized by HE-XRD/PDF probing of the lattice strain, whereas the surface activity is monitored by DRIFTS detection of the surface intermediate formation during the oxidation of propane by oxygen. The results reveal the dominance of the surface intermediate species featuring a lower degree of oxygenation upon the first C-C bond cleavage on the lower-Ni-content nanoalloy and a higher degree of oxygenation upon the second C-C bond cleavage on the higher-Ni-content nanoalloy. The face-centered-cubic-type phase structures of the nanoalloys under the oxidation condition are shown to exhibit Ni-content-dependent changes of lattice strains, featuring the strongest strain with little variation for the higher-Ni-content nanoalloy, in contrast to the weaker strains with oscillatory variation for the lower-Ni-content nanoalloys. This process is also accompanied by oxygenation of the metal components in the nanoalloy, showing a higher degree of oxygenation for the higher-Ni-content nanoalloy. These subtle differences in phase structure and surface activity changes correlate with the Ni-composition-dependent catalytic activity of the nanoalloys, which sheds a fresh light on the correlation between the dynamic change of atomic strains and the surface reactivity and has significant implications for the design of oxidation catalysts with enhanced activities.

The Healthcare Cost Burden in Adults with High Risk for Cardiovascular Disease.

OBJECTIVE: We calculated the short- and long-term care resource use and costs in adults with high-risk conditions for cardiovascular disease (HRCVD) as defined by the Canadian Cardiovascular Society dyslipidemia guidelines. METHODS: We linked Alberta health databases to identify patients aged ≥ 18 years with HRCVD between fiscal year (FY) 2012 and FY2016. The first HRCVD event was the index event. Patients were categorized into (1) primary prevention patients and (2) secondary prevention patients at the index event and were followed until death, they moved out of the province, or they were censored at March 2018. We calculated the resource use and costs for each of the 5 years after the index event. RESULTS: The study included 459,739 HRCVD patients (13,947 [3%] were secondary prevention patients). The secondary prevention patients were older (median age 61 years vs. 55 years; p < 0.001), and there were fewer females in this group (30.4% vs. 51.3%; p < 0.001). The total healthcare costs in the first year decreased over time (FY2012: 1.16 billion Canadian dollars (CA$); FY2016: CA$1.05 billion; p < 0.001). An HRCVD patient incurred CA$12,068, CA$5626, and CA$4655 during the first, second, and fifth year, respectively (p for trend < 0.001). During the first year, healthcare costs per secondary prevention patient (CA$36,641) were triple that for a primary prevention patient (CA$11,299; p < 0.001), primarily due to higher hospitalization costs in secondary prevention patients (CA$26,896 vs. CA$6051; p < 0.001). CONCLUSIONS: The healthcare costs for HRCVD patients were substantial but decreased over time. The costs were highest in the year following the index event and decreased thereafter. Secondary prevention patients incurred higher costs than the primary prevention patients.

Outcome and Cost of Optimal Control of Dyslipidemia in Adults With High Risk for Cardiovascular Disease.

BACKGROUND: We assessed the impact of optimal dyslipidemia control on mortality and costs in adults at high risk for cardiovascular disease (HRCVD). METHODS: We linked Alberta health databases to identify patients aged ≥ 18 years with HRCVD between April 2012 and March 2017. The first HRCVD event was considered the index event. Patients were categorized into (1) optimal control and (2) suboptimal control of dyslipidemia based on biomarkers and lipid-lowering therapy during the year post-index event. We measured the association between optimal dyslipidemia control and mortality and health care costs using difference-in-difference and propensity score-matching methods. RESULTS: The study included 459,739 patients with HRCVD (43,776 [9.5%] optimal patients). The optimal patients were older (median age = 62 vs 55 years; P < 0.001), included fewer female patients (37.7% vs 52%; P < 0.001), and featured a higher proportion of secondary prevention patients (15.7% vs 1.7%; P < 0.001). Compared with suboptimal patients, the optimal patients had lower adjusted mortality (0.7% vs 1.9% at 1-year and 2.9% vs 5.1% at 3-year post-index event; both P < 0.001), and higher adjusted health care costs (CA$3758 and CA$6844 at 1-year and 3-year post-index event, respectively; both P < 0.001). Among the secondary prevention group, the optimal patients had lower adjusted mortality (2.4% and 5% absolute reduction at 1-year and 3-year post-index event, respectively; both P < 0.001) at no additional costs. The results were robust across 5 definitions of optimal dyslipidemia control. CONCLUSIONS: Patients with optimal dyslipidemia control have lower mortality and incur modestly higher costs. However, secondary prevention patients experience lower mortality at no additional costs.

The Costs of Industry-Sponsored Drug Trials in Canada.

OBJECTIVE: The objective of this study was to estimate the provincial and nationwide costs of industry-sponsored drug clinical trials (CTs) in Canada. METHODS: We used the Aggregate Analysis of ClinicalTrials.gov (AACT) database, and included all industry-sponsored drug CTs that were conducted in Canada and completed in 2016. We estimated the costs of the study drugs using the market price. Estimates of the costs of management and patient services were based on industry contracts. RESULTS: The sample included 394 CTs that were conducted in 2039 facilities in Canada and provided services for 20,126 Canadian enrollees. Two-thirds of the CTs (277 of 394) were in the non-cancer category. On average, the drug costs per patient were 89,680 Canadian dollars ($Can) during the lifespan of the CTs, and were higher in cancer CTs than in non-cancer CTs ($Can216,876 vs. $Can65,274). The total costs of industry-sponsored drug CTs completed in 2016 was $Can2093.7 million. Drug costs accounted for the majority of this total ($Can1804.9 million). Ontario ($Can781.2 million) and Quebec ($Can757.5 million) had the highest costs. CONCLUSION: The costs of industry-sponsored drug CTs completed in 2016 when measured in terms of market prices in Canada were valued at $Can2.1 billion.

The Current and Future Hospitalization Cost Burden of Syncope in Canada.

BACKGROUND: Single-center studies have shown the high costs associated with the hospital evaluation of syncope. National cost estimates for syncope-related hospitalizations are sparse, and none exist in Canada. METHODS: The Canadian Institute for Health Information Discharge Abstract Database was used to identify acute care hospitalizations with a primary diagnosis of syncope between fiscal years (FY) 2004 and 2015 in all provinces and territories (except Quebec). We used multiple linear regression to calculate the trends in prevalence of hospital admissions and generalized linear regression to estimate the costs of a hospitalization. The syncope hospitalization rate and the cost per hospitalization in Quebec were assumed to be the average of the rest of the country. The future hospitalization cost burden of syncope was projected to 2030. RESULTS: There were 128,263 hospitalizations for a primary diagnosis of syncope over the 10-year study period, resulting in a total cost of $619.9 million (Canadian). An estimate of 41,044 syncope hospitalizations occurred in Quebec, costing $198.7 million. The total hospitalization cost of syncope in Canada was estimated at $818.5 million. The annual costs of syncope hospitalizations increased from $66.6 to $68.5 million between FY2004 and FY2015, respectively, and are projected to increase to $87.1 million in 2030. CONCLUSION: Hospitalization costs for syncope in Canada are high and rising. Research is needed to identify opportunities to deliver more efficient and cost-effective care.

CONTEXTE: Des études monocentriques ont mis en lumière les coûts élevés associés à l'évaluation hospitalière d'une syncope. Les estimations nationales du coût des hospitalisations liées aux syncopes sont rares, et il n'en existe aucune au Canada. MÉTHODOLOGIE: La base de données sur les congés des patients de l'Institut canadien d'information sur la santé a été utilisée pour recenser les hospitalisations de courte durée liées à un diagnostic primaire de syncope entre les années financières (AF) 2004 et 2015 dans toutes les provinces et territoires (sauf le Québec). Nous avons eu recours, d'une part, à la régression linéaire multiple pour calculer les tendances de la prévalence d'admissions à l'hôpital et, d'autre part, à la régression linéaire généralisée pour estimer les coûts d'une hospitalisation. Le taux d'hospitalisations liées à une syncope et le coût par hospitalisation au Québec ont été établis hypothétiquement à la moyenne du reste du pays. Le futur fardeau du coût des hospitalisations liées à une syncope a été projeté jusqu'en 2030. RÉSULTATS: Nous avons recensé 128 263 hospitalisations liées à un diagnostic primaire de syncope au cours de la période de 10 ans à l'étude, ce qui se traduit par un coût total de 619,9 M$ (canadiens). Selon une estimation, 41 044 hospitalisations liées à une syncope seraient survenues au Québec, au coût de 198,7 M$. Le coût total des hospitalisations liées à une syncope au Canada a été estimé à 818,5 M$. Les coûts annuels des hospitalisations liées à une syncope ont augmenté, passant de 66,6 à 68,5 M$ entre les AF 2004 et 2015, respectivement, et ils devraient encore augmenter pour atteindre 87,1 M$ en 2030. CONCLUSION: Les coûts des hospitalisations liées à une syncope au Canada sont élevés et en hausse. D'autres travaux de recherche devront être effectués pour cerner les possibilités de prestations de soins plus efficaces et rentables.

A Population-Based Study Evaluating Sex Differences in Patients Presenting to Emergency Departments With Syncope.

OBJECTIVES: This study sought to determine whether sex-specific differences in management and outcomes of syncope patients exist. BACKGROUND: Syncope is a common presentation to the emergency department (ED) and reason for hospital admission. METHODS: Patients ≥18 years of age, presenting to the ED with a primary diagnosis of syncope in Alberta, Canada, from January 1, 2007 to December 12, 2015 were included. ED records were linked to hospital records to identify patients admitted versus discharged from the ED. Outcomes included 30-day and 1-year all-cause mortality. Multivariable mixed-effect logistic regression assessed the association between sex and outcomes. RESULTS: Of the 63,274 ED syncope patients, 33,986 (53.7%) were women and 29,288 (46.3%) were men (p < 0.01). Compared with men, women were younger (51.6 ± 23.8 years for women vs. 55.1 ± 20.9 years for men; p < 0.001), less likely to arrive by ambulance (48.4% women vs. 51.7% men; p < 0.001), and had fewer comorbidities (67.9% women vs. 61.8% men with Charlson comorbidity score = 0; p < 0.001). Overall, 12.6% women and 16.8% men were admitted to hospital (p < 0.001). Regardless of discharge status, women had lower mortality rates (30-day admitted: 2.9% women and 4.4% men; p < 0.001; discharged: 0.2% women and 0.4% men; p < 0.001; and 1-year admitted: 12.6% women and 16.1% men; p < 0.001; discharged: 2.4% women and 3.7% men; p < 0.001). After adjusting for confounders, men were associated with 1.4-fold higher odds of death at 1 year. This was unchanged regardless of discharge status. CONCLUSIONS: Although women are more likely than men to present to the ED with syncope, they are less likely to be admitted to hospital. Mortality rates are lower for women, regardless of discharge status.

Assessment of Costs of Avoidable Delays in Intensive Care Unit Discharge.

Importance: Delays in transfer for discharge-ready patients from the intensive care unit (ICU) are increasingly described and contribute to strained capacity. Objective: To describe the epidemiological features and health care costs attributable to potentially avoidable delays in ICU discharge in a large integrated health care system. Design, Setting, and Participants: This population-based cohort study was performed in 17 adult ICUs in Alberta, Canada, from June 19, 2012, to December 31, 2016. Participants were patients 15 years or older admitted to a study ICU during the study period. Data were analyzed from October 19, 2018, to May 20, 2020. Exposures: Avoidable time in the ICU, defined as the portion of total ICU patient-days accounted for by avoidable delay in ICU discharge (eg, waiting for a ward bed). Main Outcomes and Measures: The primary outcome was health care costs attributable to avoidable time in the ICU. Secondary outcomes were factors associated with avoidable time, in-hospital mortality, and measures of use of health care resources, including the number of hours in the ICU and the number of days of hospitalization. Multilevel mixed multivariable regression was used to assess associations between avoidable time and outcomes. Results: In total, 28 904 patients (mean [SD] age, 58.3 [16.8] years; 18 030 male [62.4%]) were included. Of these, 19 964 patients (69.1%) had avoidable time during their ICU admission. The median avoidable time per patient was 7.2 (interquartile range, 2.4-27.7) hours. In multivariable analysis, male sex (odds ratio [OR], 0.92; 95% CI, 0.87-0.98), comorbid hemiplegia or paraplegia (OR 1.47; 95% CI, 1.23-1.75), liver disease (OR 1.20; 95% CI, 1.04-1.37), admission Acute Physiology and Chronic Health Evaluation II score (OR, 1.03; 95% CI, 1.02-1.03), surgical status (OR, 0.90; 95% CI, 0.82-0.98), medium community hospital type (OR, 0.12; 95% CI, 0.04-0.32), and admission year (OR, 1.16; 95% CI, 1.13-1.19) were associated with avoidable time. The cumulative avoidable time was 19 373.9 days, with estimated attributable costs of CAD$34 323 522. Avoidable time accounted for 12.8% of total ICU bed-days and 6.4% of total ICU costs. Patients with avoidable time before ICU discharge showed higher unadjusted in-hospital mortality (1115 [5.6%] vs 392 [4.4%]; P < .001); however, in multivariable analysis, avoidable time was associated with reduced in-hospital mortality (adjusted hazard ratio, 0.74; 95% CI, 0.64-0.85). Results were similar in sensitivity analyses. Conclusions and Relevance: In this study, potentially avoidable discharge delay occurred for most patients admitted to ICUs across a large integrated health system and translated into substantial associated health care costs.

Lack of benefit from hospitalization in patients with syncope: A propensity analysis.

STUDY OBJECTIVE: Patients with syncope are frequently admitted to the hospital, but whether this improves outcome is unknown. We tested whether hospitalization reduced mortality in patients who presented to emergency departments (EDs) with syncope. METHODS: We conducted a propensity analysis of the outcomes of patients ≥18 years old presenting to EDs with a primary diagnosis of syncope in April 2004-March 2013. The model used 1:1 nearest-neighbor matching to predicted admission using age, sex, urban residence, household income, and 14 significant comorbidities from 4 administrative databases of the province of Alberta. The primary outcome was death. RESULTS: There were 57,417 ED patients with a primary diagnosis of syncope; 8864 were admitted, and 48,553 were discharged in <24 hours. Admitted patients were older (median 76 vs 49 years), male (53% vs 45%), rural (23% vs 18%), and had lower income (median $58,599 vs $61,422); all P < 0.001. All comorbidities were higher in admitted patients (mean Charlson scores, 1.9 vs 0.7; P < 0.001). The propensity-matched hospitalized patients had higher 30-day mortality (3.5% vs 1.0%) and 1-year mortality (14.1% vs 8.6%); both P < 0.001. Mortality in all propensity quintiles was higher in the hospitalized group (all P < 0.001). The most common causes of death in 2719 patients included chronic ischemic heart disease, 14%; lung cancer, 7.1%; acute myocardial infarction, 6.9%; stroke, 3.7%; chronic obstructive pulmonary disease, 3.6%; dementia, 2.6%; and heart failure, 2.5%. CONCLUSIONS: Hospital admission did not reduce early or late mortality in patients who presented to the ED with syncope. Mortality is associated with comorbidities.

Surface oxygenation of multicomponent nanoparticles toward active and stable oxidation catalysts.

The need for active and stable oxidation catalysts is driven by the demands in production of valuable chemicals, remediation of hydrocarbon pollutants and energy sustainability. Traditional approaches focus on oxygen-activating oxides as support which provides the oxygen activation at the catalyst-support peripheral interface. Here we report a new approach to oxidation catalysts for total oxidation of hydrocarbons (e.g., propane) by surface oxygenation of platinum (Pt)-alloyed multicomponent nanoparticles (e.g., platinum-nickel cobalt (Pt-NiCo)). The in-situ/operando time-resolved studies, including high-energy synchrotron X-ray diffraction and diffuse reflectance infrared Fourier transform spectroscopy, demonstrate the formation of oxygenated Pt-NiOCoO surface layer and disordered ternary alloy core. The results reveal largely-irregular oscillatory kinetics associated with the dynamic lattice expansion/shrinking, ordering/disordering, and formation of surface-oxygenated sites and intermediates. The catalytic synergy is responsible for reduction of the oxidation temperature by ~100 °C and the high stability under 800 °C hydrothermal aging in comparison with Pt, and may represent a paradigm shift in the design of self-supported catalysts.

Feasibility of advancing the development of compact energy systems.

It is necessary to advance the development of compact energy systems for making energy from biomass like wood or switchgrass, as an alternative to the construction of highly capital-intensive large scale biorefineries. Compact energy systems consist of four individual components: a biomass preparation unit, a biomass converter, a fuel processor, and a powered engine. The individual unit processes within each component and the possible types of compact energy systems with different biomass converter technologies like fermentation, pyrolysis, and gasification are presented. The size, weight, and energy efficiency of upgrading biomass to energy using a compact energy system with various gasification technologies has been estimated. A compact energy system with a hydrogen fuel cell as a powered-engine component, processing 10 kg of dry biomass per day, generates a net energy (kW h) of -7.5, -30, 18.7, 13.1, and 11.7 with the super-critical, microwave assisted, catalytic, steam, and conventional gasification technologies as biomass converter technologies, respectively. The low yields of super-critical gasification and low efficacy of converting electric energy to heat via electromagnetic waves with microwave assisted gasification result in negative net energy with the respective compact energy system. Finally, the challenges and opportunities with the development of low weight, small size, and highly energy efficient compact energy systems built around gasification are discussed.