493 research outputs found

    New findings from the time trade-off for income approach to elicit willingness to pay for a quality adjusted life year

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    In this paper we empirically investigate how to appropriately model utility of wealth and health. We use a recently proposed alternative approach to value willingness to pay (WTP) for health, making use of trade-offs between income and life years or quality of life, which we extend to allow for a more realistic multiplicative utility function over health and money. Moreover, we show how reference-dependency can be incorporated into this model and derive its predictions for WTP elicitation. We propose three experimental elicitation procedures and test these in a feasibility study, analysing the responses under different assumptions about the discount rate. Several interesting results are reported: first, the data are highly skewed, but if we trim the 5% lowest and highest values, we obtain plausible WTP estimates. Second, the results differ considerably between procedures, indicating that WTP estimates are sensitive to the assumed utility function. Third, respondents appear to be loss averse for both health and money, which is consistent with assumptions from prospect theory. Finally, our results also indicate that respondents are more willing to trade quality of life than life years

    A noticeable difference? Productivity costs related to paid and unpaid work in economic evaluations on expensive drugs

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    Productivity costs can strongly impact cost-effectiveness outcomes. This study investigated the impact in the context of expensive hospital drugs. This study aimed to: (1) investigate the effect of productivity costs on cost-effectiveness outcomes, (2) determine whether economic evaluations of expensive drugs commonly include productivity costs related to paid and unpaid work, and (3) explore potential reasons for excluding productivity costs from the economic evaluation. We conducted a systematic literature review to identify economic evaluation

    Exact Fourier expansion in cylindrical coordinates for the three-dimensional Helmholtz Green function

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    A new method is presented for Fourier decomposition of the Helmholtz Green Function in cylindrical coordinates, which is equivalent to obtaining the solution of the Helmholtz equation for a general ring source. The Fourier coefficients of the Helmholtz Green function are split into their half advanced+half retarded and half advanced-half retarded components. Closed form solutions are given for these components in terms of a Horn function and a Kampe de Feriet function, respectively. The systems of partial differential equations associated with these two-dimensional hypergeometric functions are used to construct a fourth-order ordinary differential equation which both components satisfy. A second fourth-order ordinary differential equation for the general Fourier coefficent is derived from an integral representation of the coefficient, and both differential equations are shown to be equivalent. Series solutions for the various Fourier coefficients are also given, mostly in terms of Legendre functions and Bessel/Hankel functions. These are derived from the closed form hypergeometric solutions or an integral representation, or both. Numerical calculations comparing different methods of calculating the Fourier coefficients are presented

    Spinodal Decomposition in a Binary Polymer Mixture: Dynamic Self Consistent Field Theory and Monte Carlo Simulations

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    We investigate how the dynamics of a single chain influences the kinetics of early stage phase separation in a symmetric binary polymer mixture. We consider quenches from the disordered phase into the region of spinodal instability. On a mean field level we approach this problem with two methods: a dynamical extension of the self consistent field theory for Gaussian chains, with the density variables evolving in time, and the method of the external potential dynamics where the effective external fields are propagated in time. Different wave vector dependencies of the kinetic coefficient are taken into account. These early stages of spinodal decomposition are also studied through Monte Carlo simulations employing the bond fluctuation model that maps the chains -- in our case with 64 effective segments -- on a coarse grained lattice. The results obtained through self consistent field calculations and Monte Carlo simulations can be compared because the time, length, and temperature scales are mapped onto each other through the diffusion constant, the chain extension, and the energy of mixing. The quantitative comparison of the relaxation rate of the global structure factor shows that a kinetic coefficient according to the Rouse model gives a much better agreement than a local, i.e. wave vector independent, kinetic factor. Including fluctuations in the self consistent field calculations leads to a shorter time span of spinodal behaviour and a reduction of the relaxation rate for smaller wave vectors and prevents the relaxation rate from becoming negative for larger values of the wave vector. This is also in agreement with the simulation results.Comment: Phys.Rev.E in prin

    Patency of endoscopic ultrasound-guided gastroenterostomy in the treatment of malignant gastric outlet obstruction

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    Background and study aims Endoscopic ultrasoundguided gastroenterostomy (EUS-GE) with a lumen-apposing metal stent (LAMS) is a novel, minimally invasive technique in the palliative treatment of malignant gastric outlet obstruction (GOO). Several studies have demonstrated feasibility and safety of EUS-GE, but evidence on long-term durability is limited. The aim of this study was to evaluate patency of EUS-GE in treatment of malignant GOO. Patients and Methods An international multicenter study was performed in seven centers in four European countries. Patients who underwent EUS-GE with a LAMS between March 2015 and March 2019 for palliative treatment of symptomatic malignant GOO were included retrospectively. Our main outcome was recurrent obstruction due to LAMS dysfunction; other outcomes of interest were technical success, clinical success, adverse events (AEs), and survival. Results A total of 45 patients (mean age 69.9 ± 12.3 years and 48.9% male) were included. Median duration of followup was 59 days (interquartile range [IQR] 41–128). Recurrent obstruction occurred in two patients (6.1 %), after 33 and 283 days of follow-up. Technical success was achieved in 39 patients (86.7 %). Clinical success was achieved in 33 patients (73.3 %). AEs occurred in 12 patients (26.7 %), of which five were fatal. Median overall survival was 57 days (IQR 32–114). Conclusions EUS-GE showed a low rate of recurrent obstruction. The relatively high number of fatal AEs underscores the importance of careful implementation of EUSGE in clinical practice

    Natural Human Immunity Against Staphylococcal Protein A Relies on Effector Functions Triggered by IgG3

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    Staphylococcal protein A (SpA) is a multifunctional, highly conserved virulence factor of Staphylococcus aureus. By binding the Fc portion of all human IgG subclasses apart from IgG3, SpA interferes with antibody and complement deposition on the bacterial surface, impairing staphylococcal clearance by phagocytosis. Because of its anti-opsonic properties, SpA is not investigated as a surface antigen to mediate bacterial phagocytosis. Herein we investigate human sera for the presence of SpA-opsonizing antibodies. The screening revealed that sera containing IgG3 against SpA were able to correctly opsonize the target and drive FcÎł receptor-mediated interactions and phagocytosis. We demonstrated that IgG3 Fc is significantly more efficient in inducing phagocytosis of SpA-expressing S. aureus as compared to IgG1 Fc in an assay resembling physiological conditions. Furthermore, we show that the capacity of SpA antibodies to induce phagocytosis depends on the specific epitope recognized by the IgGs on SpA molecules. Overall, our results suggest that anti-SpA IgG3 antibodies could favor the anti-staphylococcal response in humans, paving the way towards the identification of a correlate of protection against staphylococcal infections

    Intravenous Lidocaine for Refractory Pain in Patients with Pancreatic Ductal Adenocarcinoma and Chronic Pancreatitis:A Multicenter Prospective Nonrandomized Pilot Study

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    INTRODUCTION:Refractory pain is a major clinical problem in patients with pancreatic ductal adenocarcinoma (PDAC) and chronic pancreatitis (CP). New, effective therapies to reduce pain are urgently needed. Intravenous lidocaine is used in clinical practice in patients with PDAC and CP, but its efficacy has not been studied prospectively.METHODS:Multicenter prospective nonrandomized pilot study included patients with moderate or severe pain (Numeric Rating Scale ≄ 4) associated with PDAC or CP in 5 Dutch centers. An intravenous lidocaine bolus of 1.5 mg/kg was followed by continuous infusion at 1.5 mg/kg/hr. The dose was raised every 15 minutes until treatment response (up to a maximum 2 mg/kg/hr) and consecutively administered for 2 hours. Primary outcome was the mean difference in pain severity, preinfusion, and the first day after (Brief Pain Inventory [BPI] scale 1-10). A BPI decrease ≄1.3 points was considered clinically relevant.RESULTS:Overall, 30 patients were included, 19 with PDAC (63%) and 11 with CP (37%). The mean difference in BPI at day 1 was 1.1 (SD ± 1.3) points for patients with PDAC and 0.5 (SD ± 1.7) for patients with CP. A clinically relevant decrease in BPI on day 1 was reported in 9 of 29 patients (31%), and this response lasted up to 1 month. No serious complications were reported, and only 3 minor complications (vertigo, nausea, and tingling of mouth). Treatment with lidocaine did not impact quality of life.DISCUSSION:Intravenous lidocaine in patients with painful PDAC and CP did not show an overall clinically relevant reduction of pain. However, this pilot study shows that the treatment is feasible in this patient group and had a positive effect in a third of patients which lasted up to a month with only minor side effects. To prove or exclude the efficacy of intravenous lidocaine, the study should be performed in a study with a greater sample size and less heterogeneous patient group.</p

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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