Patient Welfare and Patient Compliance: An Empirical Framework for Measuring the Benefits from Pharmaceutical Innovation

The main goal of this paper is to develop an empirical framework for evaluating the patient welfare benefits arising from pharmaceutical innovation. Extending previous studies of the welfare benefits from innovation (Trajtenberg, 1990; Hausman, 1996), this paper unpacks the separate choices made by physicians and patients in pharmaceutical decisionmaking and develops an estimable econometric model which reflects these choices. Our proposed estimator for patient welfare depends on (a) whether patients comply with the prescriptions they receive from physicians and (b) the motives of physicians in their prescription behavior. By focusing on compliance behavior, the proposed welfare measure reflects a specific economic choice made by patients. We review evidence that the rate of noncompliance ranges up to 70%, suggesting an important gulf between physician prescription behavior and realized patient welfare. Since physicians act as imperfect but interested agents for their patients, the welfare analysis based on compliance must account for the nonrandom selection of patients into drugs by their physicians. The key contribution of this paper resides in integrating the choices made by both physicians and patients into a unified theoretical framework and suggesting how the parameters of such a model can be estimated from data.

Market Segmentation and the Sources of Rents from Innovation: Personal Computers in the Late 1980's

This paper evaluates the sources of transitory market power in the market for personal computers (PCs) during the late 1980's. Our analysis is motivated by the coexistence of low entry barriers into the PC industry and high rates of innovative investment by a small number of PC manufacturers. We attempt to understand these phenomena by measuring the role that different principles of product differentiation (PDs) played in segmenting this dynamic market. Our first PD measures the substitutability between Frontier (386-based) and Non- Frontier products, while the second PD measures the advantage of a brand-name reputation (e.g., by IBM). Building on advances in the measurement of product differentiation, we measure the separate roles that these PDs played in contributing to transitory market power. In so doing, this paper attempts to account for the market origins of innovative rents in the PC industry. Our principal finding is that, during the late 1980's, the PC market was highly segmented along both the Branded (B versus NB) and Frontier (F versusNF) dimensions. The effects of competitive events in any one cluster were confined mostly to that particular cluster, with little effect on other clusters. For example, less than 5% of the market share achieved by a hypothetical entrant would be market-stealing from other clusters. In addition, the product diffe- rentiation advantages of B and F were qualitatively different. The main advantage of F was limited to the isolation from NF competitors it provided; Brandedness both shifted out the product demand curve as well as segmenting B products from NB competition. These results help explain how transitory market power (arising from market segmentation) shaped the underlying incen- tives for innovation in the PC industry during the mid to late 1980s.

Scaling laws of solar and stellar flares

In this study we compile for the first time comprehensive data sets of solar and stellar flare parameters, including flare peak temperatures T_p, flare peak volume emission measures EM_p, and flare durations t_f from both solar and stellar data, as well as flare length scales L from solar data. Key results are that both the solar and stellar data are consistent with a common scaling law of EM_p ~ T_p^4.7, but the stellar flares exhibit ~250 times higher emission measures (at the same flare peak temperature). For solar flares we observe also systematic trends for the flare length scale L(T_p) ~ T_p^0.9 and the flare duration t_F(T_p) ~ T_p^0.9 as a function of the flare peak temperature. Using the theoretical RTV scaling law and the fractal volume scaling observed for solar flares, i.e., V(L) ~ L^2.4, we predict a scaling law of EM_p ~ T_p^4.3, which is consistent with observations, and a scaling law for electron densities in flare loops, n_p ~ T_p^2/L ~ T_p^1.1. The RTV-predicted electron densities were also found to be consistent with densities inferred from total emission measures, n_p=(EM_p/q_V*V)^1/2, using volume filling factors of q_V=0.03-0.08 constrained by fractal dimensions measured in solar flares. Our results affect also the determination of radiative and conductive cooling times, thermal energies, and frequency distributions of solar and stellar flare energies.Comment: 9 Figs., (paper in press, The Astrophsycial Journal

Left ventricular to left atrial communication secondary to a paraaortic abscess: Color flow doppler documentation

Aortic root abscess occurs frequently in aortic prosthetic valve infective endocarditis. The present echocardiography report documents a ruptured abscess that led to a direct communication between the left ventricular outflow tract and the left atrium confirmed by real-time (color flow) Doppler imaging

Focus issue introduction: 3D image acquisition and display: technology, perception and applications

This Feature Issue of Optics Express is organized in conjunction with the 2021 Optica (OSA) conference on 3D Image Acquisition and Display: Technology, Perception and Applications which was held virtually from 19 to 23, July 2021 as part of the Imaging and Sensing Congress 2021. This Feature Issue presents 29 articles which cover the topics and scope of the 2021 3D conference. This Introduction provides a summary of these articles

Empirical Implications of Physician Authority in Pharmaceutical Decisionmaking

This paper studies the consequences of physician authority on pharmaceutical prescribing. Physicians engage in a costly process of particular conditions and characteristics. The relative efficiency of this matching process results from the diagnostic skill of the physician along with the investments made by the doctor in learning about different drugs. While the underlying level of physician skill or knowledge cannot be observed, differences among physicians in terms of these attributes are reflected in their prescribing behavior. We provide evidence for two major findings regarding the exercise of physician authority in this context. First, there is substantial variation in the degree to which physician prescribing is concentrated (i.e., some physicians prescribe a more diverse portfolio of drugs than others). Second, this concentration is correlated with observable drug characteristics. In particular, concentrated prescribers tend to prescribe drugs with high levels of advertising, low prices, and high (lagged) market shares. Our empirical results provide evidence for the importance of both physician effort and diagnostic ability in the prescribing process. In particular, physicians who differentiate among their patients more finely are more likely to have less concentrated prescribing portfolios and to be less sensitive to information sources which promote the use of drugs for the

SELF-DUAL NON-ABELIAN VORTICES IN A \PHI^2 CHERN-SIMONS THEORY

We study a non-Abelian Chern-Simons gauge theory in $2+ 1$ dimensions with the inclusion of an anomalous magnetic interaction. For a particular relation between the Chern-Simons (CS) mass and the anomalous magnetic coupling the equations for the gauge fields reduce from second- to first order differential equations of the pure CS type. We derive the Bogomol'nyi-type or self-dual equations for a \bphi^2 scalar potential, when the scalar and topological masses are equal. The corresponding vortex solutions carry magnetic flux that is not quantized due to the non-toplogical nature of the solitons. However, as a consequence of the quantization of the CS term, both the electric charge and angular momentum are quantized.Comment: 14 pages, Latex file, no figure

Banach spaces of universal disposition

In this paper we present a method to obtain Banach spaces of universal and almost-universal disposition with respect to a given class $\mathfrak M$ of normed spaces. The method produces, among other, the Gurari\u{\i} space $\mathcal G$ (the only separable Banach space of almost-universal disposition with respect to the class $\mathfrak F$ of finite dimensional spaces), or the Kubis space $\mathcal K$ (under {\sf CH}, the only Banach space with the density character the continuum which is of universal disposition with respect to the class $\mathfrak S$ of separable spaces). We moreover show that $\mathcal K$ is not isomorphic to a subspace of any $C(K)$-space -- which provides a partial answer to the injective space problem-- and that --under {\sf CH}-- it is isomorphic to an ultrapower of the Gurari\u{\i} space. We study further properties of spaces of universal disposition: separable injectivity, partially automorphic character and uniqueness properties

Treatment challenges associated with bone echinococcosis

Objectives In this literature review, we concentrate on epidemiology and therapy of osseous echinococcosis, with an emphasis on the recurrence risk. Methods Literature review 1930-2012. Results We retrieved 200 publications based upon single case reports or case series, mostly from resource-poor settings. Among the 721 rural patients (22% females; median age 37 years), 60% of all reported cases were from the Mediterranean region and almost all patients were immune competent. Echinococcus granulosus was identified as the most frequent species. Most infections involved a single bone (602/721; 83%) and often the spine (321 cases; 45%). In eight cases (8/702; 1%), a secondary bacterial surgical site infection was reported. Surgical intervention was performed in 702 cases (97%), with single intervention in 687 episodes (95%). Complete excision of the lesion was possible in only 117 episodes (16%). Albendazole was by far the most frequently used agent in monotherapy with various dosages, while mebendazole in monotherapy was less frequent (32 cases). The median duration of antihelminthic therapy was 6 months (range 0.7-144 months). There were 124 recurrences (17%) after a median delay of 2 years (range 0.4-17 years). In multivariate analysis, the presence of visceral organ involvement increased the odds of recurrence by 5.4 (95% CI 3.1-9.4), whereas the number of surgical interventions, the duration of antihelminthic therapy or the use of hypertonic saline did not influence recurrence. Conclusions Bone echinococcosis is a rare parasitic disease. While treatment modalities vary considerably, combined surgical and medical approaches are the standard of care with a 17% risk of recurrenc

Generalized Line Criterion for Gauss-Seidel Method.

We present a module based criterion, i.e. a sufficient condition based on the absolute value of the matrix coefficients, for the convergence of Gauss–Seidel method (GSM) for a square system of linear algebraic equations, the Generalized Line Criterion (GLC). We prove GLC to be the “most general” module based criterion and derive, as GLC corollaries, some previously know and also some new criteria for GSM convergence. Although far more general than the previously known results, the proof of GLC is simpler. The results used here are related to recent research in stability of dynamical systems and control of manufacturing systems