778 research outputs found
Further Evidence on Hedge Funds Performance.
In this analysis we identify dynamic hedge fund strategies quantitatively pursuing a Principal Component Analysis following Fung and Hsieh (1997). We extract five dominant hedge fund strategies each representing similar investment styles and analyse the performance of each strategy by employing a multi-factor model comprising both market indices and passive option strategies along the lines of Agerwal and Naik (2000). We find that the majority of the five homogenous strategies show superior performance. However, correcting for survivorship bias this superior performance disappears.Hedge funds; Investment in securities; Performance; Dynamic strategies; Hedge funds performance;
The emergence and unfolding of telemonitoring practices in different healthcare organizations
Telemonitoring, a sub-category of telemedicine, is promoted as a solution to meet the challenges in Western healthcare systems in terms of an increasing population of people with chronic conditions and fragmentation issues. Recent findings from large-scale telemonitoring programs reveal that these promises are difficult to meet in complex real-life settings which may be explained by concentrating on the practices that emerge when telemonitoring is used to treat patients with chronic conditions. This paper explores the emergence and unfolding of telemonitoring practices in relation to a large-scale, inter-organizational home telemonitoring program which involved 5 local health centers, 10 district nurse units, four hospitals, and 225 general practice clinics in Denmark. Twenty-eight interviews and 28 h of observations of health professionals and administrative staff were conducted over a 12-month period from 2014 to 2015. This studyâs findings reveal how telemonitoring practices emerged and unfolded differently among various healthcare organizations. This study suggests that the emergence and unfolding of novel practices is the result of complex interplay between existing work practices, alterations of core tasks, inscriptions in the technology, and the power to either adopt or ignore such novel practices. The study enhances our understanding of how novel technology like telemonitoring impacts various types of healthcare organizations when implemented in a complex inter-organizational context
Directional supercontinuum generation: the role of the soliton
In this paper we numerically study supercontinuum generation by pumping a
silicon nitride waveguide, with two zero-dispersion wavelengths, with
femtosecond pulses. The waveguide dispersion is designed so that the pump pulse
is in the normal-dispersion regime. We show that because of self-phase
modulation, the initial pulse broadens into the anomalous-dispersion regime,
which is sandwiched between the two normal-dispersion regimes, and here a
soliton is formed. The interaction of the soliton and the broadened pulse in
the normal-dispersion regime causes additional spectral broadening through
formation of dispersive waves by non-degenerate four-wave mixing and
cross-phase modulation. This broadening occurs mainly towards the second
normal-dispersion regime. We show that pumping in either normal-dispersion
regime allows broadening towards the other normal-dispersion regime. This
ability to steer the continuum extension towards the direction of the other
normal-dispersion regime beyond the sandwiched anomalous-dispersion regime
underlies the directional supercontinuum notation. We numerically confirm the
approach in a standard silica microstructured fiber geometry with two
zero-dispersion wavelengths
Network Dynamics in an Interorganizational Telemedicine Network:A longitudinal qualitative case study of the large-scale TeleCare North Program
Does Telecare Improve Interorganisational Collaboration?
Introduction: Previous studies have suggested that telecare can improve interorganisational collaboration within fragmented health care systems, yet this outcome has not been examined in a large-scale setting. This study explores the effects of a large-scale interorganisational telecare programme in Denmark based on home-monitoring on collaboration in a telecare network between municipalities, hospitals, and general practitioners. Methodology: Semi-structured interviews and observations of collaborating health professionals from the municipalities, hospitals, and general practitioners were undertaken and then repeated a year later. Collaboration was analysed both at the interorganisational network level and within each part of the network, including its interrelations. Results: Collaboration between municipalities and general practitioners was initially intensified as a result of implementing telecare, though this changed over time as the first start-up obstacles were overcome and the patients became more active in their treatment. Conversely, collaboration between 'hospitals and municipalities' and 'hospitals and general practitioners' was unaffected by telecare. Discussion: Changes in collaboration among municipal nurses, general practitioners, and hospital staff were related to dependency structures and municipalitiesâ newly gained central role in a telecare network. While the telecare network was initially characterised by asymmetrical dependency structures, these were partially equalised over time because of the municipalitiesâ new position in the network
Assessment of short and long-term outcomes of diabetes patient education using the health education impact questionnaire (HeiQ)
Abstract Background Type 2 diabetes is a progressive chronic illness that will affect more than 500 million people worldwide by 2030. It is a significant cause of morbidity and mortality. Finding the right care management for diabetes patients is necessary to effectively address the growing population of affected individuals and escalating costs. Patient education is one option for improving patient self-management. However, there are large discrepancies in the outcomes of such programs and long-term data are lacking. We assessed the short and long-term outcomes of diabetes patient education using the health education impact questionnaire (HeiQ). Methods We conducted a observational cohort study of 83 type 2 diabetes patients participating in patient education programs in Denmark. The seven-scale HeiQ was completed by telephone interview at baseline and 2Â weeks (76 participants, 93%) and 12Â months (66, 80%) after the patient education ended. Changes over time were assessed using mean values and standard deviation at each time point and Cohen effect sizes. Results Patients reported improvements 2Â weeks after the program ended in 4 of 7 constructs: skills and technique acquisition (ESÂ =Â 0.59), self-monitoring and insight (ESÂ =Â 0.52), constructive attitudes and approaches (ESÂ =Â 0.43) and social integration and support (ESÂ =Â 0.27). After 12Â months, patients reported improvements in 3 of 7 constructs: skills and technique acquisition (ESÂ =Â 0.66), constructive attitudes and approaches (ESÂ =Â 0.43), and emotional wellbeing (ESÂ =Â 0.44). Skills and technique showed the largest short- and long-term effect size. No significant changes were found in health-related activity or positive and active engagement in life over time. Conclusion After 12Â months, diabetes patients who participated in patient education demonstrated increased self-management skills, improved acceptance of their chronic illness and decreased negative emotional response to their disease. Applying HeiQ as an outcome measure yielded new knowledge as to what patients with diabetes can obtain by participating in a patient education
Conditional maximum likelihood estimation in polytomous Rasch models using SAS
Abstract IRT models are widely used, but often relies on distributional assumptions about the latent variable. For a simple class of IRT models, the Rasch models, conditional inference is feasible. This enables consistent estimation of item parameters without reference to the distribution of the latent variable in the population. Traditionally, specialized software has been needed for this, but conditional maximum likelihood estimation can be done using standard software for fitting generalized linear models. This paper describes a SAS macro %rasch_cml that fits polytomous Rasch models. The macro estimates item parameters using conditional maximum likelihood (CML) estimation and person locations using MLE and Warm's Weighted likelihood estimation (WLE). Graphical presentations are included: plots of item characteristic curves (ICC's) and a graphical goodness-of-fit-test is also produced
Psychometric analysis of the Patient Health Questionnaire in Danish patients with an implantable cardioverter defibrillator (The DEFIB-WOMEN study)
Evaluation of the Quick Environmental Exposure and Sensitivity Inventory in a Danish Population
Objectives. To evaluate a Danish translation of the Quick Environmental Exposure and Sensitivity Inventory (QEESI). Methods. The study included two groups: one comprised a random sample of 2000 individuals drawn from the Danish Civil Registration System; the other comprised 315 patients with chemical intolerance. Results. The evaluation suggested good reliability for the four QEESI scales in terms of internal consistency and coefficients between test and retest scores. The discriminatory validity was the largest for the Chemical (inhalant) Intolerance and Life Impact Scales. Using combined cut-off scores for these two scales provided a sensitivity of 92.1 and a specificity of 91.8 and yielded a prevalence of 8.2% in the population group. Conclusions. The Danish translation of the QEESI showed overall good reliability and validity. We recommend the use of the combined Chemical (inhalant) Intolerance and Life Impact Scales in future studies
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