MPH, Faculty of Health Sciences, University of the Witwatersrand, 2007

Atualmente, a obesidade constitui significativo problema de saúde pública em vários países, associando-se positivamente ao incremento na prevalência de doenças crônicas não transmissíveis. Isso impõe encargos substanciais à população, resultando em redução da qualidade de vida e produtividade, além de elevação dos custos dos sistemas de saúde. Assim, o presente estudo propôs avaliação econômica das estratégias terapêuticas medicamentosas para tratamento da obesidade disponíveis no Brasil, a partir de revisão sistemática de literatura direcionada para identificação de desfechos em saúde associada à estimativa de custos diretos de tratamento das alternativas disponíveis no país. A revisão sistemática de literatura identificou 17 estudos sobre perda de peso para tratamento medicamentoso baseado em sibutramina, orlistat e liraglutida. Em termos de avaliação econômica, verificou-se razão custo-efetividade (RCE) de R$506,75; R$3.116,08 e R$2.176,45 por ponto percentual de peso reduzido para sibutramina, orlistat e liraglutida, respectivamente; indicando melhor efetividade por custo para tratamento medicamentoso com sibutramina. Destaca-se que tratamento medicamentoso da obesidade requer avaliação individual da terapia recomendável, assim como acompanhamento da aderência do paciente. Adicionalmente, ressalta-se necessidade de condução de estudos sobre tratamentos com base em outros medicamentos isolados ou combinações de medicamentos, além de análise da manutenção ou reganho de peso em médio e longo prazo após término do tratamento. / Nowadays, obesity represents a significant public health problem in diverse countries, being positively associated to increased prevalence of chronic noncommunicable diseases. It imposes substantial burden to the population, resulting in losses regarding quality of life and productivity, in addition to increases in health system costs. Thus, the presente study proposed economic assessment of therapeutic strategies based on medication available in Brazilian market for treatment of obesity, using systematic literature review to identify health outcomes associated with direct costs estimation of the treatment alternatives. Systematic review of literature identified 17 studies on weight loss during obesity treatment with sibutramine, orlistat and liraglutide. Regarding economic assessment, cost-effectiveness ratios (RCE) of R$506.75; R$3,116.08 e R$2,176.45 per percentage point of weight loss for treatments with sibutramine, orlistat and liraglutide, respectively; indicating better effectiveness per cost for adoption of treatment with sibutramine. It is important highlight that medication for treatment of obesity requires individual assessment of the recommended therapy and monitoring of the patient\'s adherence to treatment. Additionally, it is advisable to perform further research on other medication available, including monotherapy or combination therapy, along with analysis of maintenance of weight or weight regain after finishing treatment in the long run.

INTRODUÇÃO: As doenças cardiovasculares estão entre as principais causas de óbito no Brasil e no mundo. Dentre as doenças cardiovasculares, a insuficiência cardíaca (IC) participa de maneira importante para morbi-mortalidade por ser via final de todas as entidades que acometem o coração. A internação hospitalar constitui momento crucial no tratamento e sobrevida dos pacientes com IC. Neste momento, em que o estado da doença atinge seu período mais crítico, é de grande importância o conhecimento dos pacientes com maior risco, que necessitam de cuidados mais intensos. No entanto, a apuração dos custos hospitalares é tarefa difícil, principalmente nas situações de alta complexidade, onde a utilização de recursos nos diversos setores do hospital, materiais e medicamentos, é muito heterogênea. Assim, a busca de variáveis clínicas capazes de ajudar a identificar os pacientes com maior risco, morbidade hospitalar (e conseqüente maior tempo de internação), e o custo destas internações foram o escopo deste estudo. OBJETIVO: primariamente, identificar variáveis clínicas capazes de predizer prognóstico de sobrevida e custos de internação numa população de pacientes internados por IC. Secundariamente, determinar custo mediano destas internações, correlacionando os as variáveis clínicas, de etiologia da cardiopatia de base, e com o perfil hemodinâmico na admissão hospitalar. Visamos ainda projetar os dados da Instituição no modelo de regressão por árvore de decisão proposto pelo estudo ADHERE. MÉTODOS: Realizamos um estudo retrospectivo na qual foram analisados dados consecutivos referentes a internações de pacientes que chegaram ao Pronto Socorro do InCor e permaneceram no Hospital por mais de 24 horas, sendo internados nos anos de 2006 e 2007. Foram avaliados dados clínicos na chegada ao pronto atendimento e evolutivos durante a internação. Foi realizada avaliação de custo da doença durante internação hospitalar através de modelo misto de análises de custos diretos contabilizados por absorção total e rateio dos setores de apoio. Análises estatísticas incluíram modelos de: regressão de proporcional de Cox para variáveis de morbidade-permanência hospitalar, regressão logística para variáveis de mortalidade hospitalar, e regressão através de árvores de decisão para definição de variáveis prioritárias. RESULTADOS: Foram avaliadas 577 internações de pacientes diferentes, sendo 60% do sexo masculino, e idade mediana de 69 anos (57-77). As principais variáveis clínicas preditoras de tempo de internação para nossa população foram: perfil hemodinâmico C, necessidade de dobutamina, ventilação mecânica, ou antibióticos. As principais variáveis clínicas preditoras de mortalidade foram: fração de ejeção, pressão arterial sistólica, clearence estimado de creatinina, ocorrência de infecção hospitalar, e a necessidade de dobutamina, noradrenalina, ou cateteres centrais. Todas estas variáveis compuseram os modelos de regressão. O custo mediano das internações foi de R$ 4.450 (1.353 - 13.432), sendo o fator independente na análise multivariada, o tempo de internação hospitalar, que teve mediana de 5 dias (2-13). A mortalidade hospitalar geral foi de 132 pacientes (23%). CONCLUSÃO: As variáveis clínicas preditoras de tempo de internação para nossa população foram: perfil hemodinâmico, necessidade de dobutamina, ventilação mecânica, ou antibióticos. As variáveis clínicas preditoras de mortalidade foram a fração de ejeção, a pressão arterial sistólica, o clearence estimado de creatinina, a ocorrência de infecção hospitalar, e a necessidade de dobutamina, noradrenalina, ou cateteres centrais. Estas variáveis foram diferentes daquelas apontadas por outros estudos. A etiologia chagásica se correlacionou à maior incidência de choque cardiogênico, caracterizando assim maiores taxas de mortalidade, tempo de permanência, e custos frente às outras etiologias. A presença de choque cardiogênico na entrada se correlacionou a altas taxas de mortalidade, internações mais prolongadas, e maiores de custos de internação. O modelo descrito pelo estudo ADHERE pôde ser aplicado em nossa população, porém, propusemos outro modelo de árvore de decisão composto pelas variáveis: presença de choque cardiogênico uréia sérica, e pressão arterial sistólica, que apresentou maior acurácia em relação ao desfecho mortalidade hospitalar. O custo das internações variou muito de acordo com a evolução clínica dos pacientes, e conseqüentemente, seu tempo de internação hospitalar. No caso de pacientes atendidos pelo SUS, menos de um terço das internações tiveram custos inferiores ao valor médio das AIHs pagas por internações de pacientes com IC. / BACKGROUND: Heart diseases are the main mortality cause in Brazil and the rest of the world. Among those diseases, heart failure (HF) is utmost importance because it is the final pathway for overall heart diseases. Acute decompensate HF is a crucial situation while treating this disease because of its severity. At this critical time, stratification of risk is imperative in order to determine care. Hospital costs determination, however, is difficult in high complexity situations that use resources in a heterogeneity manner. The look for the clinical variables that could identify patients at higher risk for morbidity (and length of stay), mortality, and costs were the main aims of this study. OBJECTIVES: primarily to identify clinical variable able to predict survive and costs in a population of patients admitted by HF. Secondarily, determine median costs for the admissions, correlating these values to clinical variables, etiologies of HF, and hemodynamic profile at entrance. We aimed also to run our data in the tree regression model previously proposed by the ADHERE registry. METHODS: we reviewed consecutively 577 admissions records of different patients admitted by acute decompensated heart failure that stayed for more than 24 hours at the hospital during 2006 and 2007. Clinical data at the admissions and in-hospital follow-up data were analyzed. Costs analysis was performed through a mix model of microcosting (for direct resources) and average costing (for indirect resources). Statistical analysis included regression models as follows: Cox proportional for length of stay variables, logistic for hospital mortality, and classification and regression tree for defining priority variables. RESULTS: among the 577 patients, 60% were men; median age was 69 years (57- 77). The main predictor variables for length of stay were as follows: C hemodynamic profile, need for dobutamine, mechanic ventilation, or antibiotics. The main predictor variables for mortality were as follows: ejection fraction, systolic blood pressure, estimated creatinine clearance, occurrence of hospital infections, and need for dobutamine, norepinephrine, or central catheters. All these variables composed the regression models. Median admission cost was R$ 4.450 (1.353 13.432). Length of stay was an independent factor for predicting costs, with median of 5 days (2-13). Inhospital mortality rate was 23% (132 patients). CONCLUSION: The main predictor variables for length of stay were as follows: hemodynamic profile, need for dobutamine, mechanic ventilation, or antibiotics. The main predictor variables for mortality were as follows: ejection fraction, systolic blood pressure, estimated creatinine clearance, occurrence of hospital infections, and need for dobutamine, norepinephrine, or central catheters. These variables differ from other studies that evaluated similar outcomes. Chagas heart disease etiology was correlated to higher rates of cardiogenic shock, mortality rates, length of stay, and costs. The model used in the ADHERE registry could be used in our population; however, we proposed another variables integrating the regression and classification tree (systolic blood pressure, blood urea nitrogen, and hemodynamic profile C). This model presented greater accuracy for hospital mortality in our population. The cost of admissions ranged according to clinical evolution of the patients, and as consequence of length of stay. Less than a third of the admissions reimbursed by the government had their costs below the mean estimated value for reimbursement

Thesis advisor: Julie H. Mortimer / This dissertation consists of two independent chapters on pricing and consumer demand in the retail sector. In chapter 1 develop an empirical model of Consumer Supermarket Choice that enables identification of heterogeneous consumer travel costs and is suitable for a wide range of policy experiments and the study of local competition. Chapter 2 is a theoretical investigation on pricing patterns in multi-product retail markets, when boundedly rational consumers' choice of a store is based on the price and valuation of a subset of goods. Estimation of demand systems in spatially differentiated retail markets is fundamental for understanding local competition and the impact of policy changes. It is also challenging, because shopping decisions consist of multiple dimensions: when to shop, where to shop and what to buy. In chapter 1 I develop an empirically tractable model of store choice in the supermarket industry and provide a way to identify consumers' heterogeneous travel costs without imposing restrictions on bundle choice. Using micro level data on a small market in New England, I estimate demand for stores using both a moment inequality approach and standard discrete choice techniques. I specify utility as a function of both store and bundle characteristics, and control for the endogeneity of expenditure on the bundle. I use the estimates of the discrete choice model to evaluate the welfare impact of 1) the closing of each individual store in the market and 2) the relocation of one of the stores. I find that travel costs are heterogeneous and marginally decreasing; that people like to shop at stores that are close, but also like to shop at multiple stores. Furthermore, people value stores differently (across consumers and shopping occasion) and trade off additional travel time for better store characteristics; utility differentials in preference for stores correspond to a distance ranging between zero and up to 3.3 miles. Variation in demand and substitution patterns across stores are explained by differences in store characteristics and by the shopping habits and geographic distribution of heterogenous consumers. Changes in market structure, like store entry and exit can have significant impact on consumer welfare. For example, removal on one of the stores results in a loss in CS that ranges between 8% and 44%. The assumption of rationality in retail shopping decisions appears very problematic when stores sell thousands of products and frequently vary their assortments and prices. Consumers are typically uncertain about prices at different stores and for a consumer to consider the entire distribution of bundles and prices might be a far too complex decision process. Furthermore, models with rational consumers are incapable of fully explaining important features of retail markets such as price dispersion, advertising and leader pric- ing. In chapter 2 I attempt to characterize optimal pricing by multi-product retailers when imperfectly informed consumers buy more than one product. The distinctive feature of the model is that there are two relevant moments to all purchase decisions. First, the choice of a store to visit, and second, the choice of the items to purchase. While consumers might rationally choose a store to best meet their specific needs and desires, the choice of the items to purchase is made only once in a store. Whether guided by impulse, contingent and unforeseen needs or in-store learning about a product, consumers often end up buying additional products which can generate higher profits for the stores. To examine the implications on retail pricing of this kind of behavior, I depart from a standard rational setup and introduce the concept of attractor goods. Using an an approach similar to that found in Osborne and Rubinstein (1998) and Spiegler (2006) I consider boundedly rational con- sumers whose choice between stores is based solely and entirely on the price and valuation of a subset of goods, the attractors. I show that retailer's pricing decisions have to take into account not only the direct effect of prices on a product's demand but also the effect on the demand for the other products sold in the store. The optimal pricing schedule will be a decreasing function of the goods' attractiveness, and pricing below marginal cost might be optimal for some goods. The model provides a rationale for the strategy of loss leader pricing and offers an intuitive explanation to countercyclical markups. / Thesis (PhD) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

O objetivo principal deste trabalho é sistematizar e automatizar o cálculo de lajes maciças e retangulares de edifícios, utilizando-se a Teoria das Charneiras Plásticas. Apresentam-se as formulações necessárias para a sua automatização. Aborda-se também a questão relativa às deformações nas lajes maciças em concreto necessidade de consideração das dependentes do tempo. Por fim, faz-se um estudo comparativo com o método elástico para dimensionamento de lajes maciças em concreto e com o sistema de lajes treliçadas, através de aplicações em dois pavimentos de lajes, analisando-se os aspectos técnicos e financeiros (custos) dos resultados. / The main purpose of this work is to systematize the building rectangular compact slab calculation, using the yield line theory. The necessary formulation is presented. Deflections of reinforced concrete slabs are also discussed, making evident that cracking and time dependent effects are important parameters to be considered. Finally, a comparison with the elastic method for compact slabs design and with the lattice slab systems is presented, considering two examples of building floors, taking into account technical and financial (expenses) aspects of the results.

A teoria econômica explica que os preços necessariamente refletem a igualdade entre o custo marginal e a receita marginal. Já a teoria de marketing recomenda que os preços sejam definidos em consonância ao valor. O problema é que os estudos empíricos têm mostrado que a realidade não corresponde a nenhuma dessas duas teorias, pois, na realidade, a maior parte das empresas define os preços com base nos custos. Entretanto, esses estudos não têm evidenciado se a combinação dos custos à margem, recorrentemente encontrada, configura a forma ou a essência da determinação dos preços. Mais especificamente, pode-se afirmar que os estudos empíricos normalmente não têm aprofundado a investigação para avaliar se a fórmula \"custos mais margem\" refere-se apenas à forma mecânica de operacionalizar o estabelecimento dos preços ou refere-se tanto à forma quanto à essência do processo. Quando a fórmula designa a essência do processo, tem-se uma definição de preços marcada pela essência custos, na qual a margem é arbitrária e deixa de conectar os custos a outros tipos de informações. Nesse sentido, a fim de transcender as limitações dos prévios trabalhos empíricos, esta pesquisa teve a meta de investigar a forma e a essência do estabelecimento dos preços em empresas industriais localizadas no Brasil e, mais do que isso, averiguar os fatores que explicam o processo marcado pela essência custos. A coleta de dados aconteceu mediante um levantamento conduzido entre fevereiro de 2016 e junho de 2016. Esse levantamento implicou o envio de um questionário para a população da pesquisa, inicialmente formada por 1.616 empresas industriais relacionadas pela Revista Exame \"Melhores e Maiores\" e/ou pela Revista Noticiários de Equipamentos Industriais \"Top Five\" nas edições de 2014 e 2015. 380 respostas foram obtidas e propiciaram uma taxa de resposta de 28%. Foram tomadas medidas para assegurar as validades de conteúdo, de critério e de constructo, com destaque a um pré-teste em três fases e a duas análises do viés da não resposta. O teste de confiabilidade da pesquisa resultou em um alfa de Cronbach de 0,794. Os dados foram analisados a partir de estatísticas descritivas, de análises de correspondência e de dois modelos de regressão ordinal. Os achados desta pesquisa ilustraram: (a) a importância de segregar as empresas em tomadoras e formadoras de preços; (b) as dificuldades de obtenção de informações sobre os preços da concorrência nos formadores de preços; e (c) os diferentes tipos de informações usados no processo de definição dos preços. Os resultados ainda sugeriram que dois fatores explicam positivamente a essência custos nos formadores de preços (a diferenciação e a percepção que há prejuízos na colocação de preços inferiores ao resultado indicado pelos \"custos mais margem\") e que um fator explica negativamente a essência custos (estratégia de preço premium). Nos tomadores de preços, três fatores explicam positivamente a essência custos (a percepção que há prejuízos na colocação de preços inferiores ao resultado indicado pelos \"custos mais margem\", o isomorfismo coercitivo e o uso dos custos totais) enquanto que cinco fatores explicam negativamente a essência custos (o grande porte, a propensão de cópia dos concorrentes, a não disposição dos clientes em pagar o valor, o isomorfismo normativo e a experiência). Finalmente, concluiu-se que a combinação \"custos mais margem\" pode ser a forma sem ser a essência do estabelecimento dos preços, uma vez que a margem pode conectar os custos aos demais tipos de informações. Implicações para os pesquisadores, para os profissionais, para os docentes e para os discentes foram discutidas. / Economic theory explains how prices are set at a level that equates marginal cost and marginal revenue. On the other hand, marketing theory explains how prices should be set based on value. The problem is that researchers argue that neither of these two theories really explains the pricing practices because empirical studies have concluded that most companies set prices based on cost. However, the empirical studies have not yet examined whether cost-plus formulas represent either the shape or the essence of pricing. In other words, the empirical studies have not yet provided an in-depth analysis of the circumstances in which cost-plus formulas are shape rather than essence of pricing. It is important to mention that a cost-based essence is found when margin is arbitrary and does not connect cost to other types of information. In attempting to address this issue, the present research was designed with the purpose of investigating shape and essence of pricing in industrial companies located in Brazil. More specifically, the goal of this work was to draw attention to the factors that determine the adoption of a cost-based essence. Data for this study were gathered through a survey carried out between February 2016 and June 2016. A questionnaire was sent to 1,616 industrial companies included on the list of \"Melhores e Maiores\" Exame Magazine and/or on the list of \"Noticiários de Equipamentos Industriais - Top 5\" Magazine (2014 and 2015 editions). The total usable responses were 380 representing a 28% response rate. Content, criterion and construct validities were assessed through procedures that included both a three-stage pre-test and two investigations for non-response bias. Reliability test resulted in a Cronbach\'s Alpha of 0.794. Descriptive statistics, correspondence analyses and two ordinal regressions were conducted for purposes of analysis. The findings from this research illustrated: (a) the importance of separating companies into price-takers and price-makers; (b) the price-makers\' difficulties in obtaining data about competitors\' prices; and (c) the different types of information used in the pricing process. The results also suggested that, for price makers, cost-based essence was positively associated with two predictors (differentiation and perception that prices lower than cost-plus calculations can lead to losses), but it was negatively related to one predictor (premium pricing strategy). For price-takers, cost-based essence was positively associated with three predictors (perception that prices lower than cost-plus calculations can lead to losses, coercive isomorphism and use of full costs), but it was negatively related to five predictors (large size, competitors\' ability to copy products, customer\'s non-willingness to pay, normative isomorphism and experience). Finally, it was concluded that cost-plus may be the shape without being the essence of pricing because margin can connect costs to other types of information. Implications for researchers, practitioners, teachers and students were discussed.

The aim of this thesis is to analyze the costs of the chosen company and through the analysis suggest provisions which will lead to costs optimization. The practical part starts with introducing the company, which was chosen for this thesis. Then the analysis of operating and financial cost is made. The optimization suggestions of selected costs are based on this analysis.

The work presented here is part of a wider research programme oriented around three specific questions. First, how do individual agents appropriate returns from innovation and how is this affected by the availability (or not) of intellectual property rights such as copyrights and patents? Second, how does this translate into the aggregate production of knowledge, once one takes account of the interaction between producers and the cumulative nature of the process of knowledge production? Finally, How can we incorporate this into an estimate of the welfare trade-off inherent in intellectual property rights (the basic prerequisite for formulating rational IP policy)? The dissertation contains theoretical work on each of these questions together with a brief introductory preamble and a review of the existing literature on the economics of knowledge.

This dissertation considers the interconnections between trade and transportation. Through various theoretical and empirical analyses, I provide novel evidence of the simultaneity of trade and transportation, of spillover effects across integrated transport markets, and of the influence of the international transport sector on trade policy effectiveness and natural disaster induced trade disruptions. In the first substantive chapter, I develop a model of international trade and transportation. Accounting for the joint-production present in the international container shipping industry, I illustrate that freight rates adjust to differences in the international demands for transport and can result in balanced or imbalanced equilibrium trade in the presence of asymmetric freight rates. The empirical results exhibit the simultaneity of international trade and transportation costs and show that the dependence of transport costs on the trade imbalance can lead to spillover effects across bilateral export and import markets. In the second substantive chapter, I investigate the effects of maritime trade policy on bilateral trade in the presence of trade imbalances. Using the previously developed model, I show that the trade elasticities with respect to carrier costs vary systematically across transport markets, bilateral trade imbalances and differentiated products. Empirically, I estimate the varying effects of an EU environmental policy on U.S.-EU trade and provide strong evidence in support of the theoretical results. In the third substantive chapter, I analyze the dynamics and spatial distribution of the trade effects induced by natural disasters. I develop a spatial gravity model of international trade and apply the model to monthly US port level trade data. Empirically, I estimate the dynamic evolution of trade effects caused by Hurricane Katrina differentiating trade disruptions at the local port level. The estimates point to the static and dynamic resilience of international trade. While ports closest to Katrina's epicenter experience significant short-run reductions that can be of permanent nature, international trade handled by nearby ports rises in response to this disaster, both in the short- and in the long-run. Overall, the analysis underlines the significance of local infrastructure networks to reduce the devastation inflicted by natural disasters. This dissertation includes previously unpublished co-authored material.

Transaction costs and resampling are two important issues that need great attention in every portfolio investment planning. In practice costs are incurred to rebalance a portfolio. Every investor tries to find a way of avoiding high transaction cost as much as possible. In this thesis, we investigated how transaction costs and resampling affect portfolio investment. We modified the basic mean-variance optimization problem to include rebalancing costs we incur on transacting securities in the portfolio. We also reduce trading as much as possible by applying the resampling approach any time we rebalance our portfolio. Transaction costs are assumed to be a percentage of the amount of securities transacted. We applied the resampling approach and tracked the performance of portfolios over time, assuming transaction costs and then no transaction costs are incurred. We compared how the portfolio is affected when we incorporated the two issues outlined above to that of the basic mean-variance optimization.