186 research outputs found

    Morphological acceleration factor: usability, accuracy and run time reductions

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    Within SISYPHE 6.2, the option is created by BAW to use a morphological acceleration factor (MF) within the coupled TELEMAC2D-SISYPHE model. Multiplying both the evolution and the time by the same factor the model jumps forward in time, reducing the required computation time. This paper presents the usability of this approach, the gains in computation time and the loss of accuracy of this approach. Three different cases were used: a laboratory case of a trench in a constant flow, a river flood case and an estuarine test case. For the river flood case, a single event with varying water discharges, the approach is unsuitable. Using the MF implies that the water levels change too rapidly, altering the hydrodynamics. The same would be the case for tidal flow, but the morphological acceleration factor can still be used due to the repeating nature of the tide [1]. The downside is that strictly the results using a factor N are only valid after exactly N tides. For steady cases the approach can be used flexibly without limitations. Comparisons with the measured data the trench case show that the MF can be used with only limited loss of accuracy. The simulation time reduces rapidly, while the model skills only reduce marginally, up to the MF is 90. The simulation time initially reduces rapidly. For the larger model of an estuary, the gain using a MF of 20 reduced the run time by a factor 20. In this case however, the model does show some significant changes in the prediction

    To pool or not to pool in hospitals: a theoretical and practical comparison for a radiotherapy outpatient department

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    This paper examines whether urgent and regular patients waiting for a consultation at a radiotherapy outpatient department should be pooled or not. Both queuing theory and discrete event simulation were applied to a realistic case study. The theoretical approach shows that pooling is not always beneficial with regard to the waiting times of urgent patients. Furthermore, the practical approach indicates that the separation of queues may require less capacity to meet the waiting time performance target for urgent as well as regular patients. The results seem to be of general interest for hospital

    Extending the use of the Endoscopic Endonasal Sinus and Skull Base Surgery Questionnaire in a cross-sectional study:Patients with chronic rhinosinusitis versus healthy controls

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    Objectives There are several instruments to assess health-related quality of life (HRQoL) in chronic rhinosinusitis (CRS). Unfortunately, none of them evaluates all three health domains (physical, social and psychological) important to assess the overall well-being of the patient. The Endoscopic Endonasal Sinus and Skull Base Surgery Questionnaire (EES-Q) does assess all these elements. Initially, the EES-Q is validated to evaluate the impact of endoscopic endonasal surgery (EES) on HRQoL. The aim of this study is to assess whether EES-Q outcomes differ in patients with CRS compared with healthy individuals. Therefore, extending the use of the EES-Q for all CRS patients. Design Cross-sectional study. Setting Tertiary referral hospital. Participants One hundred patients with uncontrolled CRS (50% with nasal polyps) scheduled to receive EES. The questionnaire was completed preoperatively. Healthy control subjects (n = 100) without any history of sinusitis or a known current medical treatment at a hospital were included. Main outcome measures Mann-Whitney U test was performed to identify differences in EES-Q scores (domain scores and EES-Q score). Results The median EES-Q score in CRS patients (33.8) was significantly higher (p < 0.001) than in the control group (10.4). As well as the physical (52.5 vs. 16.4, p < 0.001), psychological (13.8 vs. 5.0, p < 0.001) and social (37.5 vs. 2.5, p < 0.001) domain scores. Conclusions With this study, we are extending the use of the EES-Q. It indicates that the EES-Q can be a valuable clinical tool to assess multidimensional HRQoL in all patients with CRS

    Prospective evaluation of multidimensional health-related quality of life after endoscopic endonasal surgery for pituitary adenomas using the endoscopic endonasal sinus and skull base surgery questionnaire

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    Objective: Social functioning is an important factor in the evaluation of postoperative health-related quality of life (HRQoL) for pituitary adenoma patients. In a prospective cohort study multidimensional HRQoL of non-functioning (NFA) and functioning (FA) pituitary adenoma patients were evaluated following endoscopic endonasal surgery using the endoscopic endonasal sinus and skull base surgery questionnaire (EES-Q). Methods: Prospectively, 101 patients were included. The EES-Q was completed preoperatively and postoperatively (2 weeks, 3 months, 1 year). Sinonasal complaints were completed daily during the first week postoperatively. Preoperative and postoperative scores were compared. A generalized estimating equation (uni- and multivariate) analysis was performed to identify significant HRQoL changes related to selected covariates. Results: Two weeks postoperatively, physical (p &lt;.05) and social (p &lt;.05) HRQoL are worse and psychological (p &lt;.05) HRQoL improved compared with preoperatively. Three months postoperatively, psychological HRQoL (p =.01) trended back to baseline and no differences in physical or social HRQoL were reported. One year postoperatively, psychological (p =.02) and social (p =.04) HRQoL improved while physical HRQoL remained stable. FA patients report a worse HRQoL preoperatively (social, p &lt;.05) and 3 months postoperatively (social, p &lt;.02 and psychological, p &lt;.02). Sinonasal complaints peak in the first days postoperatively and gradually return to presurgical levels 3 months postoperatively. Conclusions: The EES-Q provides meaningful information on multidimensional HRQoL to improve patient-centred health care. Social functioning remains the most difficult area in which to achieve improvements. Despite the relatively modest sample size, there is some indication that the FA group continues to show a downward trend (and thus improvement) even after 3 months, when most other parameters reach stability. Level of evidence: Level II—B.</p

    Prospective evaluation of multidimensional health-related quality of life after endoscopic endonasal surgery for pituitary adenomas using the endoscopic endonasal sinus and skull base surgery questionnaire

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    Objective: Social functioning is an important factor in the evaluation of postoperative health-related quality of life (HRQoL) for pituitary adenoma patients. In a prospective cohort study multidimensional HRQoL of non-functioning (NFA) and functioning (FA) pituitary adenoma patients were evaluated following endoscopic endonasal surgery using the endoscopic endonasal sinus and skull base surgery questionnaire (EES-Q). Methods: Prospectively, 101 patients were included. The EES-Q was completed preoperatively and postoperatively (2 weeks, 3 months, 1 year). Sinonasal complaints were completed daily during the first week postoperatively. Preoperative and postoperative scores were compared. A generalized estimating equation (uni- and multivariate) analysis was performed to identify significant HRQoL changes related to selected covariates. Results: Two weeks postoperatively, physical (p &lt;.05) and social (p &lt;.05) HRQoL are worse and psychological (p &lt;.05) HRQoL improved compared with preoperatively. Three months postoperatively, psychological HRQoL (p =.01) trended back to baseline and no differences in physical or social HRQoL were reported. One year postoperatively, psychological (p =.02) and social (p =.04) HRQoL improved while physical HRQoL remained stable. FA patients report a worse HRQoL preoperatively (social, p &lt;.05) and 3 months postoperatively (social, p &lt;.02 and psychological, p &lt;.02). Sinonasal complaints peak in the first days postoperatively and gradually return to presurgical levels 3 months postoperatively. Conclusions: The EES-Q provides meaningful information on multidimensional HRQoL to improve patient-centred health care. Social functioning remains the most difficult area in which to achieve improvements. Despite the relatively modest sample size, there is some indication that the FA group continues to show a downward trend (and thus improvement) even after 3 months, when most other parameters reach stability. Level of evidence: Level II—B.</p
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