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Objective To study mortality and readmissions for older patients admitted during more and less busy hospital circumstances. Design Cohort study where we identified patients that were admitted to the same hospital, during the same month and day of the week. We estimated effects of inflow of acute patients and the number of concurrent acute inpatients. Mortality and readmissions were analysed using stratified Cox-regression. Setting All people 80 years and older acutely admitted to Norwegian hospitals between 2008 and 2016. Main outcome measures Mortality and readmissions within 60 days from admission. Results Among 294 653 patients with 685 197 admissions, mean age was 86 years (standard deviation 5). Overall, 13% died within 60 days. An interquartile range difference in inflow of acute patients was associated with a hazard ratio (HR) of 0.99, 95% confidence interval (95% CI) 0.98 to 1.00). There was little evidence of differences in readmissions, but a 7% higher risk (HR 1.07, 95% CI 1.06 to 1.09) of being discharged outside ordinary daytime working hours. Conclusions Older patients admitted during busier circumstances had similar mortality and readmissions to those admitted during less busy periods. Yet, they showed a higher risk of discharge outside daytime working hours. Despite limited effects of busyness on a hospital level, there could still be harmful effects of local situations.

IntroductionContinuous general practitioner (GP) and patient relations associate with positive health outcomes. Termination of GP-practice is unavoidable, while consequences of final breaks in relations are less explored. We will study how an ended GP-relation affects patient’s health care utilization and mortality, compared to patients with a continuous GP-relation.Methods and analysisLinking personal-level national registries data on GP-affiliation, sociodemographic characteristics, health care use and mortality, from 2008 to 2021, we will identify patients of GPs terminating practice, and match these GP-patient pairs on age, sex (both), immigrant status and education (patient), and number of patients and practice period (GPs), to GP-patient pairs with a continuous relationship in other municipalities, and compare acute and elective primary and specialist health care use mortality, before and after ended GP-practice, using Poisson regression with high-dimensional fixed effects. We will address expected modifying factors, such as patients with complex health care needs, quality of termination and GP-availability in the municipalities.Ethics and disseminationThis study protocol is part of the approved project Improved Decisions with Causal Inference in Health Services Research, 2016/2158/REK Midt (the Regional Committees for Medical and Health Research Ethics) and does not require consent. We will publish in peer-reviewed journals, accessible in NTNU Open, and present at scientific conferences. To reach a broader audience, we will summarize articles in the project’s web page, regular and social media, and disseminate to relevant stakeholders.Strengths and limitations of this studyThis study adds to research on GP-patient relation continuity and associations, exploring termination of relations and designing a natural experiment in register data, facilitating causal inference.The study includes the entire Norwegian population and their general practitioners (GPs) from 2008 to 2021, linking several mandatory, high-quality, healthcare, and demographic registers on a personal level.The register data include exact time points (xxx or months? xxx) for the intervention, termination of GP-relation, and the outcomes, health care utilization and death.By matching GP-patient pairs in practice period and distinct municipalities, we minimize time-varying confounders and dilution of effects.As in all observational studies, our results may be influenced by residual confounding

Aims Few studies have investigated potential consequences of strained surgical resources. The aim of this cohort study was to assess whether a high proportion of concurrent acute surgical admissions, tying up hospital surgical capacity, may lead to delayed surgery and affect mortality for hip fracture patients. Methods This study investigated time to surgery and 60-day post-admission death of patients 70 years and older admitted for acute hip fracture surgery in Norway between 2008 and 2016. The proportion of hospital capacity being occupied by newly admitted surgical patients was used as the exposure. Hip fracture patients admitted during periods of high proportion of recent admissions were compared with hip fracture patients admitted at the same hospital during the same month, on similar weekdays, and times of the day with fewer admissions. Results Among 60,072 patients, mean age was 84.6 years (SD 6.8), 78% were females, and median time to surgery was 20 hours (IQR 11 to 29). Overall, 14% (8,464) were dead 60 days after admission. A high (75th percentile) proportion of recent surgical admission compared to a low (25th percentile) proportion resulted in 20% longer time to surgery (95% confidence interval (CI) 16 to 25) and 20% higher 60-day mortality (hazard ratio 1.2, 95% CI 1.1 to 1.4). Conclusion A high volume of recently admitted acute surgical patients, indicating probable competition for surgical resources, was associated with delayed surgery and increased 60-day mortality. Cite this article: Bone Joint J 2021;103-B(2):264–270.

Purpose A reduction in the length of hospital stay may threaten patient safety. This study aimed to estimate the effect of organizational pressure to discharge on 60-day mortality among hip fracture patients. Patients and methods In this cohort study, hip fracture patients were analyzed as if they were enrolled in a sequence of trials for discharge. A hospital's discharge tendency was defined as the proportion of patients with other acute conditions who were discharged on a given day. Because the hospital's tendency to discharge would affect hip fracture patients in an essentially random manner, this exposure could be regarded as analogous to being randomized to treatment in a clinical trial. The study population consisted of 59,971 Norwegian patients with hip fractures, hospitalized between 2008 and 2016, aged 70 years and older. To calculate the hospital discharge tendency for a given day, we used data from all 5,013,773 other acute hospitalizations in the study period. Results The probability of discharge among hip fracture patients increased by 5.5 percentage points (95% confidence interval (CI)=5.3-5.7) per 10 percentage points increase in hospital discharges of patients with other acute conditions. The increased risk of death that could be attributed to a discharge from organizational causes was estimated to 3.7 percentage points (95% CI=1.4-6.0). The results remained stable under different time adjustments, follow-up periods, and age cut-offs. Conclusion This study showed that discharges from organizational causes may increase the risk of death among hip fracture patients.

Aims Few studies have investigated potential consequences of strained surgical resources. The aim of this cohort study was to assess whether a high proportion of concurrent acute surgical admissions, tying up hospital surgical capacity, may lead to delayed surgery and affect mortality for hip fracture patients. Methods This study investigated time to surgery and 60-day post-admission death of patients 70 years and older admitted for acute hip fracture surgery in Norway between 2008 and 2016. The proportion of hospital capacity being occupied by newly admitted surgical patients was used as the exposure. Hip fracture patients admitted during periods of high proportion of recent admissions were compared with hip fracture patients admitted at the same hospital during the same month, on similar weekdays, and times of the day with fewer admissions. Results Among 60,072 patients, mean age was 84.6 years (SD 6.8), 78% were females, and median time to surgery was 20 hours (IQR 11 to 29). Overall, 14% (8,464) were dead 60 days after admission. A high (75th percentile) proportion of recent surgical admission compared to a low (25th percentile) proportion resulted in 20% longer time to surgery (95% confidence interval (CI) 16 to 25) and 20% higher 60-day mortality (hazard ratio 1.2, 95% CI 1.1 to 1.4). Conclusion A high volume of recently admitted acute surgical patients, indicating probable competition for surgical resources, was associated with delayed surgery and increased 60-day mortality. Cite this article: Bone Joint J 2021;103-B(2):264–270.

Increasing the utilisation of unused capacity in hospitals is a health policy goal, but there is concern that little unused capacity remains. The objective of the study was to examine how healthcare personnel experience and deal with pressure on capacity in the somatic specialist health services.In this qualitative study, we conducted semi-structured interviews with unit heads and doctors and nurses involved in discharging patients in two Norwegian hospital trusts. Nine interviews (both individual and group) with altogether 19 informants were carried out in the period October 2017-February 2018. The interviews were analysed using systematic text condensation.Pressure on hospital capacity was described as continual pressure to treat more patients. The informants used the term 'undercapacity': a situation in which increased demands without sufficient resources were detrimental to something or someone. Elderly patients who had completed their treatment and were waiting for the provision of municipal services were regarded as particularly vulnerable, since they were often overrepresented among the patients moved between departments and wards in order to free up capacity when beds were urgently needed. The hospital staff felt they had little influence on the type of municipal services the patients were offered following discharge.The informants stated that their daily work was negatively affected by undercapacity. Health professionals' perceptions of pressure on hospital capacity constitute vital knowledge in policy formation in the field.

Background: Crowding in emergency departments (EDs) is a challenge globally. To counteract crowding in day-to-day operations, better tools to improve monitoring of the patient flow in the ED is needed. The objective of this study was the development of a continuously updated monitoring system to forecast emergency department (ED)arrivals on a short time-horizon incorporating data from prehospital services. Methods: Time of notification and ED arrival was obtained for all 191,939 arrivals at the ED of a Norwegian university hospital from 2010 to 2018. An arrival notification was an automatically captured time stamp which indicated the first time the ED was notified of an arriving patient, typically by a call from an ambulance to the emergency service communication center. A Poisson time-series regression model for forecasting the number of arrivals on a 1-, 2- and 3-h horizon with continuous weekly and yearly cyclic effects was implemented. We incorporated time of arrival notification by modelling time to arrival as a time varying hazard function. We validated the model on the last full year of data. Results: In our data, 20% of the arrivals had been notified more than 1 hour prior to arrival. By incorporating time of notification into the forecasting model, we saw a substantial improvement in forecasting accuracy, especially on a one-hour horizon. In terms of mean absolute prediction error, we observed around a six percentage-point decrease compared to a simplified prediction model. The increase in accuracy was particularly large for periods with large inflow. Conclusions: The proposed model shows increased predictability in ED patient inflow when incorporating data on patient notifications. This approach to forecasting arrivals can be a valuable tool for logistic, decision making and ED resource management. © The Author(s). 2019Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, andreproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link tothe Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Background Increasing the utilisation of unused capacity in hospitals is a health policy goal, but there is concern that little unused capacity remains. The objective of the study was to examine how healthcare personnel experience and deal with pressure on capacity in the somatic specialist health services. Material and method In this qualitative study, we conducted semi-structured interviews with unit heads and doctors and nurses involved in discharging patients in two Norwegian hospital trusts. Nine interviews (both individual and group) with altogether 19 informants were carried out in the period October 2017-February 2018. The interviews were analysed using systematic text condensation. Results Pressure on hospital capacity was described as continual pressure to treat more patients. The informants used the term 'undercapacity': a situation in which increased demands without sufficient resources were detrimental to something or someone. Elderly patients who had completed their treatment and were waiting for the provision of municipal services were regarded as particularly vulnerable, since they were often overrepresented among the patients moved between departments and wards in order to free up capacity when beds were urgently needed. The hospital staff felt they had little influence on the type of municipal services the patients were offered following discharge. Interpretation The informants stated that their daily work was negatively affected by undercapacity. Health professionals' perceptions of pressure on hospital capacity constitute vital knowledge in policy formation in the field.

Background and purpose: There are numerous studies on the weekend effect for hip fracture patients, with conflicting results. We analyzed time of admission and discharge, and the association with mortality and length of hospital stay in more detail. Material and methods: We used data from 61 211 surgically treated hip fractures, 55 211 patients, admitted to Norwegian hospitals 2008-2014. All patients were aged 50 years or older. Data were analyzed with Cox’ and Poisson regression. Results: Mortality within 30 days did not differ substantially by day of admission, although admissions on Sundays and holidays had a slightly increased mortality. The hazard ratios were 1.08 (95% confidence interval (CI) 0.97-1.20) for Sundays, and 1.18 (CI 0.98-1.41) for holidays, relative to Mondays. For patients admitted between 6:00 am and 7:00 am the hazard ratio was 1.41 (CI 1.10-1.80) relative to patients admitted between 2:00 pm and 3:00 pm. Discharges during weekends and holidays were associated with a substantial higher mortality than weekday discharges. Patients admitted from Friday to Sunday generally stayed shorter in hospital than patients admitted during other days. Interpretation: Our results indicate that the discussion on weekday versus weekend admission effects might have distracted attention from other important factors, such as time of day of admission, and day of discharge from hospital treatment. © 2018 The Author(s). Published by Taylor & Francis on behalf of the Nordic Orthopedic Federation. This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non-Commercial License (https://creativecommons.org/licenses/by/4.0)

Background Actigraphy could be an objective alternative to clinical ratings of motor activity in bipolar disorder (BD), which is of importance now that increased activity and energy are added as cardinal symptoms of (hypo)mania in the DSM-5 and commonly used rating scales give inadequate information about motor symptoms. To date, most actigraphy studies have been conducted in groups and/or used mean activity levels as the variable of interest. The novelty of this case series is therefore to indicate the potential of actigraphy and non-parametric analysis as an objective and personalized marker of intra-individual activity patterns in different phases of BD. To our knowledge, this is the first case series that provides an objective assessment of non-linear dynamics in within-person activity patterns during acute BD episodes. Results We report on three cases of bipolar I disorder with 24-h actigraphy recordings undertaken during the first few days of two or more separate admissions for an acute illness episode, including admissions for individuals in different phases of BD, or with different levels of severity in the same phase of illness. For each recording, we calculated mean activity levels over 24 h, but especially focused on key measures of variability and complexity in activity. Intra-individual activity patterns were found to be different according to phase of illness, but showed consistency within the same phase. With increasing psychotic symptoms, there was evidence of a lower overall level and greater irregularity in activity. As such, sample entropy (a measure of irregularity) may have particular utility in characterizing mania and psychotic symptoms, while assessment of the distribution of rest versus activity over 24 h may distinguish between phases of BD within an individual. Conclusions This case series indicates that objective, intra-individual, real-time recordings of patterns of activity may have clinical impact as a valuable adjunct to clinical observation and symptom ratings. We suggest that actigraphy combined with detailed mathematical analysis provides a biological variable that could become an important tool for developing a personalized approach to diagnostics and treatment monitoring in BD. © The Author(s) 2018. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

We investigate a Gaussian quadrature rule and the corresponding orthogonal polynomials for the oscillatory weight function $e^{i\omega x}$ on the interval $[-1,1]$. We show that such a rule attains high asymptotic order, in the sense that the quadrature error quickly decreases as a function of the frequency $\omega$. However, accuracy is maintained for all values of $\omega$ and in particular the rule elegantly reduces to the classical Gauss-Legendre rule as $\omega \to 0$. The construction of such rules is briefly discussed, and though not all orthogonal polynomials exist, it is demonstrated numerically that rules with an even number of points are always well defined. We show that these rules are optimal both in terms of asymptotic order as well as in terms of polynomial order., Comment: 26 pages, 9 figures

Several recent numerical schemes for high frequency scattering simulations are based on the extraction of known phase functions from an oscillatory solution. The remaining function is typically no longer oscillatory and as such it can be approximated numerically with a number of degrees of freedom that does not depend on the frequency of the original problem. Knowledge of the phase of a solution typically comes from asymptotic analysis, for example from Geometrical Optics. We consider integral equation formulations of time-harmonic scattering by a smooth and convex obstacle and focus on the so-called shadow boundaries. They are the points where the incoming waves are tangential to the boundary of the scatterer. We devise a numerical method that incorporates advanced results from asymptotic analysis which describe the frequency-dependent transitional behaviour of the solution uniformly across these points. We describe and resolve an apparent conflict between two theories that describe the asymptotic behaviour of this problem. They are the well-known Geometric Theory of Diffraction and the rigourous asymptotic analysis by Melrose and Taylor, based on microlocal analysis. ispartof: TW Reports vol:74 issue:2 pages:454-476 status: published

High order variants of the classical Stormer-Cowell methods are still a popular class of methods for computations in celestial mechanics. In this work we shall investigate the absolute stability of Stormer-Cowell methods close to zero, and present a characterization of the stability of methods of all orders. In particular, we show that many methods are not absolutely stable at any point in a neighborhood of the origin.

In this paper we demonstrate that the numerical method of steepest descent fails when applied in a straight forward fashion to the most commonly occurring highly oscillatory integrals in scattering theory. Through a polar change of variables, however, the integral can be reformulated so that it can be solved efficiently using a combination of oscillatory integration techniques and classical quadrature. The approach is described in detail and demonstrated numerically with some oscillatory integral examples. The numerical examples demonstrate that our approach avoids the failure in some special cases, such as in an acoustic scattering model oscillatory integral with observation point located in the illuminated region. This paves the way for using the framework of numerical steepest descent methods on a wider class of problems, like the 3D high frequency scattering from convex obstacles, up to now only handled in a satisfactory way by methods due to Ganesh and Hawkins (J Comp Phys 230:104–125, 2011).

A formulation of the problem of scattering from obstacles with edges is presented. The formulation is based on decomposing the field into geometrical acoustics, first-order, and multiple-order edge diffraction components. An existing secondary-source model for edge diffraction from finite edges is extended to handle multiple diffraction of all orders. It is shown that the multiple-order diffraction component can be found via the solution to an integral equation formulated on pairs of edge points. This gives what can be called an edge source signal. In a subsequent step, this edge source signal is propagated to yield a multiple-order diffracted field, taking all diffraction orders into account. Numerical experiments demonstrate accurate response for frequencies down to 0 for thin plates and a cube. No problems with irregular frequencies, as happen with the Kirchhoff-Helmholtz integral equation, are observed for this formulation. For the axisymmetric scattering from a circular disc, a highly effective symmetric formulation results, and results agree with reference solutions across the entire frequency range.

The scattering of sound by convex bodies with rigid surfaces can be modeled accurately without any wavenumber restriction using an edge source integral equation (ESIE) [A. Asheim and U. P. Svensson, J. Acoust. Soc. Am. 133 (2013) 3681-3691]. This edge diffraction-based approach has known limitations for non-convex scattering geometries, and the most challenging case might be an aperture in a thin screen. For such apertures, the ESIE predicts that only first-order diffraction occurs because the ESIE has no inclusion of the so-called slope diffraction effect. This effect occurs when the diffraction wave vanishes but its derivative is different from zero. This paper focuses on the low-frequency sound transmission through apertures in screens, as well as into ducts. A reference solution is established with a boundary element (BE) method for the particle velocity field in the aperture, which illustrates the singular behavior near the edges. The field in the aperture is also computed with first-order diffractio...

For the problem of edge diffraction from an edge of finite length a frequency-domain solution, obtained from an analytical time-domain solution, has been presented by Svensson et al. [Acta. Acust. Acust. 95, 568-572]. This formulation takes the form of a Fourier-type integral whose evaluation is expensive in the high frequency range. This paper demonstrates that by using tailored highly oscillatory quadrature methods based on asymptotic properties of the integral, accurate approximations in the high frequency case can be obtained with little computational effort.

We consider the solution of high-frequency scattering problems in two dimensions, modeled by an integral equation on the boundary of a smooth scattering object. We devise a numerical method to obtain solutions on only parts of the boundary with little computational effort. The method incorporates asymptotic properties of the solution and can therefore attain particularly good results for high frequencies. We show that the integral equation in this approach reduces to an ordinary differential equation.

We propose a variant of the numerical method of steepest descent for oscillatory integrals by using a low-cost explicit polynomial approximation of the paths of steepest descent. A loss of asymptotic order is observed, but in the most relevant cases the overall asymptotic order remains higher than a truncated asymptotic expansion at similar computational effort. Theoretical results based on number theory underpinning the mechanisms behind this effect are presented.

A crossing between the asymptotic expansion of an oscillatory integral and Filon-type methods is obtained by applying a Filon-type method to the error term in the asymptotic expansion, which is in itself an oscillatory integral. The efficiency of the approach is investigated through analysis and numerical experiments, revealing a method which in many cases performs better than the Filon-type method. It is shown that considerable savings in terms of the required number of potentially expensive moments can be expected. The case of multivariate oscillatory integrals is discussed briefly.

In computer simulations of sound in enclosures, diffraction components can be added to geometrical acoustics ones for increased accuracy. A computational problem with diffraction is the large number of higher-order terms that is generated. A recent frequency-domain edge source integral equation (ESIE) efficiently handles the sum of all higher-order diffraction for rigid, external scattering objects, while computing first-order diffraction separately. Here, a time-domain formulation of the same ESIE is presented. An initial version handles higher-order diffraction for separate scattering objects, such as stage ceiling reflectors, and the extension to general geometries is outlined. With this approach, in a first step an incident transient sound field is computed at discretized edge points, including the outgoing directivity. In a second step, the effects of diffraction of arbitrarily high order is handled by solving the IE iteratively, yielding the complete edge source time signals. In a third step, the edge source signals are propagated to receiver points. Numerical issues will be discussed, including discretization strategies and how to handle shadow zone boundary singularities.

A new integral equation for the scattering from rigid, or pressure-release, convex polyhedra and disks is presented. It is based on edge diffraction as a complement to the geometrical acoustics components, and uses directional edge sources as unknowns in the frequency-domain integral equation. Comparisons with reference results show that the new method gives correct results down to 0 Hz in spite of being a geometrically based method [Asheim & Svensson, Report TW610, KU Leuven, Dept. of Computer Science, 2012]. The two-dimensional unknowns are solved for all edges, straight or curved, of the scattering object, but this reduces to a one-dimensional unknown for certain geometries such as axisymmetric scattering from a circular thin disk, or plane-wave incidence onto a polygonal cylinder. The general integral equation can be solved with the regular Nystrom technique, iteratively or by direct inversion. The scattered field is computed in a post-processing stage, and is added to the geometrical acoustics and fi...