Multipole Extraction: A novel, model independent method

A novel method for extracting multipole amplitudes in the nucleon resonance region from electroproduction data is presented. The method is based on statistical concepts and it relies heavily on Monte Carlo and simulation techniques; it produces precise identification and determination of the contributing multipole amplitudes in the resonance region and for the first time a rigorous determination of the associated experimental uncertainty. The results are demonstrated to be independent of any model bias. The method is applied in the reanalysis of the $Q^{2}=0.127 GeV^2/c^2$ Bates and Mainz $N\to \Delta$ data.Comment: Proceedings, "Shape of Hadrons" Workshop, 27-29 April 2006, Athens, GREEC

On hadron deformation: a model independent extraction of EMR from pion photoproduction data

The multipole content of pion photoproduction at the $\Delta^+ (1232)$ resonance has been extracted from a data set dominated by recent Mainz Microtron (MAMI) precision measurements. The analysis has been carried out in the Athens Model Independent Analysis Scheme (AMIAS), thus eliminating any model bias. The benchmark quantity for nucleon deformation, $EMR = E2/M1 = E_{1+}^{3/2}/M_{1+}^{3/2}$, was determined to be $-2.5 \pm 0.4_{stat+syst}$, thus reconfirming in a model independent way that the conjecture of baryon deformation is valid. The derived multipole amplitudes provide stringent constraints on QCD simulations and QCD inspired models striving to describe hadronic structure. They are in good agreement with phenomenological models which explicitly incorporate pionic degrees of freedom and with lattice QCD calculations.Comment: 14 pages, 9 figures, 2 table

Comments on the Relativity of Shape

In this talk I address three topics related to the shape of hadrons: 1. The Lorentz contraction of bound states. Few dedicated studies of this exist - I describe a recent calculation for ordinary atoms (positronium). 2. Does the A-dependence of nuclear structure functions indicate a change of proton shape in the nuclear environment? (My short answer is no.) 3. The size of Fock states contributing to processes involving large momentum transfers. End-point configurations can be transversally extended and yet sufficiently short-lived to contribute coherently to hard scattering.Comment: Talk at the Workshop on the Shape of Hadrons, 27-29 April 2006 in Athens, Greece. 11 pages, 15 figure

High prices, not waste or over-use, drive high health care costs in the US

The US spends nearly 18 percent of its GDP on health care, making it a real outlier among high-income countries in this area. But what is behind this unusually high level of health care spending? Irene Papanicolas investigates common beliefs about why spending is so high, including that US residents use more health care services, have poorer quality of care, and use 'too much' inpatient care. She finds that higher costs in the US are largely driven by higher prices across a wide range of health care services such as surgical procedures and drugs, as well as administrative complexity and costs

The new NHS: financial incentives for quality?

In April 2002, five years after the Blair government’s proposals to create a ‘New NHS [National Health Service]’, the government outlined the key priorities that would mark the NHS reform. The main reforms involved patient choice supported by a system of ‘Payment by Results’ (PbR) under which hospitals would be funded on the activity they undertook. PbR is a case based payment system, a type of system increasingly being adopted as the main form of provider payment across industrialised countries. The literature on this type of payment system and experiences from other countries identifies many di!erent behavioural incentives that can have both positive and negative impacts on quality of care. This thesis investigates the quality implications observed so far in England, for seven conditions which represent a spectrum of important clinical areas that are admitted through both emergency and elective admissions. In order to identify changes in quality, this thesis first considers how to construct an appropriate measure of quality. The first part of the thesis utilizes two di!erent methodological techniques used for quality measurement; a latent variable approach and a technique put forward by McClellan and Staiger (1999) using Vector Autoregressions. The results from these techniques indicate that quality measurement approaches di!er markedly with regards to how much measurement and systematic error they are able to filter out of raw outcome data. Finally, the new indicators created by these techniques are used to evaluate the quality impact the introduction of PbR as the main form of hospital payment has had in England. The analysis indicates that since the policy’s implementation, there have been di!erential quality e!ects on the di!erent conditions. However, for the most part this indicates an improvement in mortality outcomes, and a reduction in the variation of outcomes across hospitals. As found, the interpretation of readmissions has to be approached with caution as more severe patients being kept alive through quality improving measures on mortality create more mixed signals for the readmission indicators. In two conditions we find changes in activity that are indicative of e"ciency gains, in the form of better coding and adoption of new technology, both as a result of differences in reimbursement categories

The challenges of using cross-national comparisons of efficiency to inform health policy

Many comparative efficiency metrics focus on scrutinising the operation of specific parts of a single health system. This article reviews the key issues involved in international comparisons of various aspects of efficiency. It examines data sources and analytic techniques used to create comparative indicators, and discusses approaches to interpreting variations. It also highlights key challenges and promising new initiatives, such as the consistent use of international definitions and technical developments, such as data linkages, which hold the potential to enhance work in this area

Perceptions of health care access in Europe: How universal is universal coverage?

The past decade has witnessed a growing interest in the ability of health systems to protect citizens from the financial consequences associated with ill health and the use of medical care. In order to improve financial protection and access to care the WHO World Health Report 2010 firmly emphasizes that health systems move towards universal coverage of their populations. Of all regions, Europe has shown the most commitment to the goal of universal coverage. However, not all Europeans may feel as though they are able to access care if in fact they should need it. It is therefore important to investigate how the citizens of different European countries perceive their access to health care in order to better understand who these individuals are and what role different systems can play in providing better access to care