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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Efeitos do Programa Bolsa Família sobre o mercado de trabalho de jovens e adultos

Correia, Luís Carlos Falcão 10 May 2016 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2016-08-10T12:20:58Z No. of bitstreams: 1 luiscarlosfalcaocorreia.pdf: 1354537 bytes, checksum: 9923b5e459d1530ba2234ee5be8348b0 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-08-10T13:03:22Z (GMT) No. of bitstreams: 1 luiscarlosfalcaocorreia.pdf: 1354537 bytes, checksum: 9923b5e459d1530ba2234ee5be8348b0 (MD5) / Made available in DSpace on 2016-08-10T13:03:22Z (GMT). No. of bitstreams: 1 luiscarlosfalcaocorreia.pdf: 1354537 bytes, checksum: 9923b5e459d1530ba2234ee5be8348b0 (MD5) Previous issue date: 2016-05-10 / O objetivo desta dissertação é compreender os efeitos do Programa Bolsa Família (PBF) sobre o mercado de trabalho de seus beneficiários e analisar alguns de seus possíveis efeitos adversos. O PBF é uma transferência de renda destinada às famílias de baixa renda com o intuito de aliviar a condição de pobreza extrema e gerar capital humano por meio das condicionalidades. Utilizou-se nas análises um painel longitudinal de dados provenientes das duas rodadas da Pesquisas de Avaliação de Impacto do Programa Bolsa Família (AIBF I e II, conduzidas nos anos de 2005 e 2009, respectivamente) realizada por contratação do Ministério de Desenvolvimento Social e Combate à Fome (MDS). A metodologia empregada teve como base o método das diferenças em diferenças concomitante ao pareamento por escore de propensão. Os resultados empíricos obtidos ajudam a refutar a hipótese do “efeito preguiça”, demonstram um incentivo à sub-declaração da renda dos beneficiários; um aumento da informalidade laboral e um desincentivo à procura por trabalho dos indivíduos beneficiários. / The aim of this dissertation is to understand the effects of the Bolsa Familia Programme (PBF) over the labor market of its beneficiaries and analyze its likely adverse effects. The PBF is a conditional cash transfer designated to low income household in order to alleviate extreme poverty and generate human capital through its conditionalities. It was used a longitudinal panel data made of first and second PBF impact evaluation surveys (held in 2005 and 2009, respectively) performed by hiring of the Ministry of Social Development and Fight against Hunger (MDS). The methodology applied was the difference in differences combined with the propensity score matching. The empirical results obtained, help to disprove the hypothesis of "laziness effect", demonstrate an incentive to under-reporting of income of the beneficiaries; an increase in labor informality and a disincentive to looking for new jobs for the beneficiary individuals.
142

The performance of inverse probability of treatment weighting and propensity score matching for estimating marginal hazard ratios

Nåtman, Jonatan January 2019 (has links)
Propensity score methods are increasingly being used to reduce the effect of measured confounders in observational research. In medicine, censored time-to-event data is common. Using Monte Carlo simulations, this thesis evaluates the performance of nearest neighbour matching (NNM) and inverse probability of treatment weighting (IPTW) in combination with Cox proportional hazards models for estimating marginal hazard ratios. Focus is on the performance for different sample sizes and censoring rates, aspects which have not been fully investigated in this context before. The results show that, in the absence of censoring, both methods can reduce bias substantially. IPTW consistently had better performance in terms of bias and MSE compared to NNM. For the smallest examined sample size with 60 subjects, the use of IPTW led to estimates with bias below 15 %. Since the data were generated using a conditional parametrisation, the estimation of univariate models violates the proportional hazards assumption. As a result, censoring the data led to an increase in bias.
143

Uma avalia??o do Programa Ci?ncia sem Fronteiras : efeitos sobre desempenho, trancamento e conclus?o

Concei??o, Otavio Canozzi 23 March 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-08-07T13:36:00Z No. of bitstreams: 1 DIS_OTAVIO_CANOZZI_CONCEICAO_COMPLETO.pdf: 1480241 bytes, checksum: 6c742bea6a2e5e1360c0f6751123d488 (MD5) / Made available in DSpace on 2017-08-07T13:36:00Z (GMT). No. of bitstreams: 1 DIS_OTAVIO_CANOZZI_CONCEICAO_COMPLETO.pdf: 1480241 bytes, checksum: 6c742bea6a2e5e1360c0f6751123d488 (MD5) Previous issue date: 2017-03-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The present dissertation evaluates the Science without Borders program focusing on three outcome variables. To achieve this goal, the work is divided into two essays. The first essay addresses the causal impact of the program on the performance of CsF alumni from the 2013 National Student Performance Exam (ENADE) microdata. The results are compared with two control groups: the first composed by students who also made international academic mobility, but through other initiatives and the second by the non-exchange students. The strategy of comparing the CsF?s alumni with the exchange students aims to mitigate the problems of self-selection, because we can expect more similar characteristics between these groups, both with regard to motivation to study abroad and observable characteristics. The methodology used was the Propensity Score Matching (PSM), using different pairing algorithms to check the validity of the findings. The results show that the alumni of the program present better grades than the exchange students, both in the general formation part and in the specific component of the ENADE exam. The second essay examines dropout and completion rates in the CsF students? course from the microdata of the Higher Education Census of 2014 and 2015. For this purpose, a panel of students was constructed, divided into the same groups of the first essay, which allowed to identify their trajectories in the course. The methodology used involved two techniques: a multinomial logit and the Markov transition matrices. The evidence found shows that CsF students evades more the course and conclude it at lower rates in the expected time, according to the serial grade of the course, than both comparison groups. The results of the multinomial logit model, controlling characteristics of individuals, institutions, courses and regions, suggest that the program has a ceteris paribus effect on the extension of student time in the university. / A presente disserta??o avalia o programa Ci?ncia Sem Fronteiras (CsF) com foco em tr?s vari?veis de resultado. Para atingir esse objetivo, o trabalho est? dividido em dois ensaios. O primeiro ensaio trata do impacto causal do programa sobre o desempenho dos ex-bolsistas do CsF a partir dos microdados do Exame Nacional de Desempenho dos Estudantes (ENADE) de 2013. Os resultados s?o analisados comparativamente a dois grupos de controle: o primeiro composto por estudantes que tamb?m realizaram interc?mbio acad?mico internacional, por?m por interm?dio de outras iniciativas e o segundo por n?o intercambistas. A estrat?gia de compar?-los com os intercambistas visa mitigar os problemas de autossele??o, porque se espera caracter?sticas mais semelhantes entre esses grupos, tanto no que tange ? motiva??o para estudar no exterior quanto em caracter?sticas observ?veis. A metodologia empregada foi o Propensity Score Matching (PSM), sendo utilizados diferentes algoritmos de pareamento para conferir validade aos achados. Os resultados revelam que os ex-bolsistas do programa apresentam melhores notas que os intercambistas, tanto na parte de forma??o geral quanto no componente espec?fico da prova do ENADE. O segundo ensaio analisa a evas?o e a taxa de conclus?o no curso de alunos do CsF a partir dos microdados do Censo da Educa??o Superior de 2014 e 2015. Para tanto, construiu-se um painel de estudantes, divididos de acordo com os mesmos grupos do primeiro ensaio, que permitiu identificar suas trajet?rias no curso. A metodologia utilizada envolveu duas t?cnicas: um logit multinomial e as matrizes de transi??o de Markov. As evid?ncias encontradas mostram que os alunos do CsF trancam mais o curso e se formam a menores taxas no tempo esperado, de acordo com a grade seriada do curso, do que ambos os grupos de compara??o. Os resultados do modelo logit multinomial, controlando caracter?sticas dos indiv?duos, das institui??es, cursos e regi?es, sugerem que o programa tem um efeito ceteris paribus sobre a prorroga??o do tempo do aluno na universidade.
144

Stratégies palliatives à la non-randomisation en santé mentale : score de propension et techniques d’ajustement apparentées. Méthodologie appliquée à la prise en compte des facteurs de confusion dans le cas de la schizophrénie / Palliative management to non-randomisation in Mental Health : propensity score and related control methods. Methodology applied in the field of schizophrenia

Sarlon, Emmanuelle 09 January 2014 (has links)
Objectif : L’objectif est l’étude de plusieurs méthodes de prise en compte des facteurs de confusion, mesurés ou non mesurés, ce en situation observationnelle de population de patients psychotiques ou schizophrènes. Méthodes : Deux méthodes ont été utilisées : le score de propension (adaptés aux données mesurées) et les analyses de sensibilité (pour les informations non mesurées). Le champ d’application est celui de l’épidémiologie clinique en psychiatrie, et plus spécifiquement celui de la schizophrénie. Le développement s’appuie sur trois parties successives. La première partie met en exergue la question de la discussion du biais résiduel. Pour cela, on s’appuie sur les résultats d’une étude transversale d’exposition à un facteur contextuel (la prison), ce dans le cadre de la présence de troubles psychotiques (au sens axe DSM IV), à partir d’une méthodologie d’ajustement conventionnelle classique. La deuxième partie est une comparaison d’une technique d’ajustement classique à un ajustement par score de propension. Pour cela, on utilise les résultats issus d’une étude de cohorte avec la survenue d’un évènement selon l’exposition à un traitement en population schizophrène, à partir de l’utilisation du score de propension comme outil d’ajustement. La troisième partie est une synthèse sur la modélisation de l’incertitude et des biais de confusion non mesurés multiples. Les théories et méthodes sont décrites, puis appliquées aux résultats des deux études précédentes. Résultats : L’étude transversale, dont les résultats non montrés jusqu’à présent, permet de poser la problématique de la qualité de l’ajustement dans le cadre d’une exposition à un facteur en situation observationnelle. L’étude de cohorte permet de comparer une technique d’ajustement classique à un ajustement par score de propension (SP). Nous avons étudié plusieurs méthodes d’ajustement (multivarié standard, avec ajustement sur SP, avec appariement sur SP). Et nous mettons en évidence que, selon la méthode d’ajustement utilisée, les résultats obtenus sont différents. La méthode de stratification sur SP semble être la meilleure. Les méthodes de prise en compte des facteurs de confusion non mesurés sont ensuite étudiées. Une première étape fait état de l’apport des théories probabilistes et des techniques apparentées, ensuite une combinaison de ces théories est proposée avec une application pratique aux deux études présentées précédemment. Conclusion : Dans le cas des études observationnelles, l’objectif de ce travail a été d’étudier, de décrire et d’appliquer des techniques de modélisation pour mieux prendre en compte les différences initiales, potentiellement source de confusion. C’est un travail à la frontière entre la méthodologie, les biostatistiques et l’épidémiologie. Nous nous appuyons sur des difficultés rencontrées, en pratique en épidémiologie psychiatrique (pathologies mentales à étiologies multifactorielles et interdépendantes) pour proposer une approche pragmatique de la prise en compte optimale des facteurs de confusion potentiels, mesurés ou non mesurés. / Objective : To evaluate control methods for measured or unmeasured confusion bias, in observational situation of psychotic or schizophrenic patients. Methods : Propensity score method (for measured confusion bias) and analyses of sensibility (for unmeasured confusion bias) were applied in the field of psychiatric epidemiology, specifically in schizophrenia. In first, the question of residual bias was underlined by the results of a transversal study. The exposition at a contextual parameter (prison) was studied in link with psychotic disorders (DSM IV), with a classic control method.Second, to lead to an unbiased estimation of treatment effect, we compared a classic control method with a method based on propensity score. These approach were applied to a cohort of French schizophrenic patients where we studied the event (relapse) by the treatment exposition (polypharmacy or not).Third, we developed a synthesis on modelisation of uncertainty and non-measured confusion bias. Theories and methods were described, and then applied on results of previous studies. Results : The transversal study, with non-demonstrated results still then, allow us to reach the question of control quality in the case of exposition to a parameter in observational situation. The cohort study permit to compare a classic control method and propensity score (PS). We highlighted different results according to some control method. Stratification method on PS seemed to be the best method to predict relapse according to treatment exposition. Non-measured bias control methods were then described. And a combination of probabilistic methods was applied to the previous studies. Conclusion : In the case of observational studies, the objective was to study, to describe and to apply modelisation methods to take in account differences at baseline, potentially source of confusion bias. This research is at the crossroads of methodology, biostatistics and epidemiology.
145

Impacto do Programa Bolsa Família sobre a aquisição de alimentos em famílias brasileiras de baixa renda / Martins, APB. Impact of the Bolsa Família Program on food purchases in low-income Brazilian families

Ana Paula Bortoletto Martins 10 June 2013 (has links)
INTRODUÇÃO: Programas de transferência de renda começaram a ser implantados no Brasil em 1990, foram gradativamente expandidos até 2003 e, a partir de então, foram integrados no Programa Bolsa Família. As avaliações de impacto dos programas de transferência de renda sobre alimentação dos beneficiários brasileiros são escassas e não apresentam resultados consistentes. OBJETIVO: Avaliar o impacto do Programa Bolsa Família (doravante denominado programa) sobre a aquisição de alimentos em famílias de baixa renda no Brasil. MÉTODOS: Foram utilizados dados da Pesquisa de Orçamentos Familiares realizada em 2008-09 em uma amostra probabilística de 55.970 domicílios brasileiros. Esta pesquisa coletou em cada domicílio dados relativos à quantidade e custo de todas as aquisições de alimentos e bebidas realizadas em um período de sete dias consecutivos. O valor per capita do gasto semanal e da energia diária, relativos a cada item alimentar, foram calculados. A avaliação de impacto foi realizada para o conjunto dos domicílios de baixa renda (com renda per capita inferior a R$210,00) e, separadamente, para os domicílios deste conjunto com renda superior e inferior à mediana, doravante denominados, respectivamente, domicílios pobres e extremamente pobres. O impacto do programa sobre a aquisição de alimentos foi estabelecido comparando-se indicadores da aquisição de alimentos entre domicílios beneficiados e não beneficiados pelo programa, que foram agrupados em blocos e pareados com base no escore de propensão de cada domicílio possuir moradores beneficiários. Pelo método do pareamento com escore de propensão criaram-se blocos de domicílios beneficiados e não beneficiados pelo programa homogêneos com relação a um grande elenco de potenciais variáveis de confundimento para a associação entre a condição de participar do programa e a aquisição domiciliar de alimentos. Os indicadores da aquisição de alimentos utilizados incluíram o gasto com a aquisição de alimentos e a quantidade de alimentos adquirida ou sua disponibilidade. Os valores per capita do montante gasto em reais e da disponibilidade em energia foram comparados levando-se em conta o conjunto dos itens alimentares e três grupos criados com base na extensão e propósito do processamento industrial a que o item alimentar foi submetido: alimentos in natura ou minimamente processados, ingredientes culinários processados e produtos prontos para consumo (processados ou ultraprocessados). O significado estatístico das comparações entre os blocos de domicílios beneficiados e não beneficiados pelo programa foi avaliado com o emprego do teste t de Student pareado. RESULTADOS: Comparados aos domicílios não beneficiados, os domicílios beneficiados pelo programa apresentaram maior gasto total com alimentação (p=0,015), maior disponibilidade de energia proveniente do conjunto de itens alimentares (p=0,010) e maior disponibilidade proveniente de alimentos e de ingredientes culinários. Não houve diferenças significativas entre beneficiados e não beneficiados pelo programa com relação ao gasto ou à disponibilidade de produtos prontos para consumo. Internamente ao grupo de alimentos, houve diferenças significativas favoráveis aos domicílios beneficiados pelo programa com relação ao gasto e à disponibilidade de alimentos como carnes, tubérculos e hortaliças. Não houve diferenças quanto a alimentos básicos como arroz e feijão. Resultados semelhantes foram observados para os domicílios pobres e extremamente pobres, ainda que as diferenças favoráveis aos domicílios beneficiados pelo programa tenham sido menos expressivas na condição de extrema pobreza. CONCLUSÃO: O impacto do Programa Bolsa Família em famílias de baixa renda traduziu-se em maior gasto domiciliar com alimentação, maior disponibilidade de alimentos in natura ou minimamente processados e ingredientes culinários e maior disponibilidade de alimentos que usualmente diversificam e melhoram a qualidade nutricional da dieta. Os efeitos do programa foram menores para famílias extremamente pobres / INTRODUCTION: Conditional cash transfer programs were implemented for the first time in Brazil in 1990. They were gradually expanded until 2003 and thereafter they were incorporated to the Bolsa Família Program. The assessment of the influence of conditional cash transfer programs on food consumption of Brazilian beneficiaries is scarce and the results of the studies are inconsistent. OBJECTIVES: To assess the impact of the Bolsa Família Program (hereafter identified as program) on household food availability in low-income families in Brazil. METHODS: The study analyzed data on a probabilistic sample of 55,970 households as part of the 2008-09 Household Budget Survey. The survey collected data on quantity and cost of all food and beverage purchased by the households during seven consecutive days. The per capita weekly expenditure and the daily energy of each food item were calculated. The assessment of the impact of the program was carried out for the group of low-income households (monthly per capita income up to R$ 210.00) and stratified for households with income above or below the median. Hereafter, these households are identified, respectively, as poor and extremely poor households. To assess the impact of the Program, food availability indicators were compared among of paired blocks of households, beneficiaries or non-beneficiaries of the program. These pairs were created based on the propensity score of each household to have beneficiary individuals. Using the propensity score matching method, pairs of blocks were created, which were homogeneous regarding many potential confounding variables for the association between the program and food acquisition. The per capita weekly expenditure and the daily energy consumption were compared considering all food items and three food groups based on the extent and the purpose of the industrial food processing applied to them: in natura or minimally processed foods, processed culinary ingredients and ready-to-eat products (processed or ultra-processed products). The comparisons between the blocks of beneficiaries and nonbeneficiaries households were carried out through paired \'t\' test. RESULTS: Compared to the non-beneficiaries, the beneficiaries households presented higher food expenditure (p=0.015), higher total energy availability (p=0.010) and higher availability of foods and culinary ingredients. There were no differences between groups regarding the expenditure and the availability of ready-to-eat products. Inside de group of foods, the expenditure and the availability of meat, tubers and vegetables were higher for the beneficiaries of the program. There were no differences regarding staple Brazilian foods like rice and beans. Similar results were observed for poor and extremely poor households, but the magnitude of the differences was lower for the households that were extremely poor. CONCLUSION: The impact of the Bolsa Família Program among low income families resulted in higher food expenditure, higher availability of foods and culinary ingredients and higher availability of foods that usually diversify and improve the diet quality. The effects of the Program seem to be lower for the extremely poor families
146

Impacto do Programa Bolsa Família sobre a aquisição de alimentos em famílias brasileiras de baixa renda / Martins, APB. Impact of the Bolsa Família Program on food purchases in low-income Brazilian families

Martins, Ana Paula Bortoletto 10 June 2013 (has links)
INTRODUÇÃO: Programas de transferência de renda começaram a ser implantados no Brasil em 1990, foram gradativamente expandidos até 2003 e, a partir de então, foram integrados no Programa Bolsa Família. As avaliações de impacto dos programas de transferência de renda sobre alimentação dos beneficiários brasileiros são escassas e não apresentam resultados consistentes. OBJETIVO: Avaliar o impacto do Programa Bolsa Família (doravante denominado programa) sobre a aquisição de alimentos em famílias de baixa renda no Brasil. MÉTODOS: Foram utilizados dados da Pesquisa de Orçamentos Familiares realizada em 2008-09 em uma amostra probabilística de 55.970 domicílios brasileiros. Esta pesquisa coletou em cada domicílio dados relativos à quantidade e custo de todas as aquisições de alimentos e bebidas realizadas em um período de sete dias consecutivos. O valor per capita do gasto semanal e da energia diária, relativos a cada item alimentar, foram calculados. A avaliação de impacto foi realizada para o conjunto dos domicílios de baixa renda (com renda per capita inferior a R$210,00) e, separadamente, para os domicílios deste conjunto com renda superior e inferior à mediana, doravante denominados, respectivamente, domicílios pobres e extremamente pobres. O impacto do programa sobre a aquisição de alimentos foi estabelecido comparando-se indicadores da aquisição de alimentos entre domicílios beneficiados e não beneficiados pelo programa, que foram agrupados em blocos e pareados com base no escore de propensão de cada domicílio possuir moradores beneficiários. Pelo método do pareamento com escore de propensão criaram-se blocos de domicílios beneficiados e não beneficiados pelo programa homogêneos com relação a um grande elenco de potenciais variáveis de confundimento para a associação entre a condição de participar do programa e a aquisição domiciliar de alimentos. Os indicadores da aquisição de alimentos utilizados incluíram o gasto com a aquisição de alimentos e a quantidade de alimentos adquirida ou sua disponibilidade. Os valores per capita do montante gasto em reais e da disponibilidade em energia foram comparados levando-se em conta o conjunto dos itens alimentares e três grupos criados com base na extensão e propósito do processamento industrial a que o item alimentar foi submetido: alimentos in natura ou minimamente processados, ingredientes culinários processados e produtos prontos para consumo (processados ou ultraprocessados). O significado estatístico das comparações entre os blocos de domicílios beneficiados e não beneficiados pelo programa foi avaliado com o emprego do teste t de Student pareado. RESULTADOS: Comparados aos domicílios não beneficiados, os domicílios beneficiados pelo programa apresentaram maior gasto total com alimentação (p=0,015), maior disponibilidade de energia proveniente do conjunto de itens alimentares (p=0,010) e maior disponibilidade proveniente de alimentos e de ingredientes culinários. Não houve diferenças significativas entre beneficiados e não beneficiados pelo programa com relação ao gasto ou à disponibilidade de produtos prontos para consumo. Internamente ao grupo de alimentos, houve diferenças significativas favoráveis aos domicílios beneficiados pelo programa com relação ao gasto e à disponibilidade de alimentos como carnes, tubérculos e hortaliças. Não houve diferenças quanto a alimentos básicos como arroz e feijão. Resultados semelhantes foram observados para os domicílios pobres e extremamente pobres, ainda que as diferenças favoráveis aos domicílios beneficiados pelo programa tenham sido menos expressivas na condição de extrema pobreza. CONCLUSÃO: O impacto do Programa Bolsa Família em famílias de baixa renda traduziu-se em maior gasto domiciliar com alimentação, maior disponibilidade de alimentos in natura ou minimamente processados e ingredientes culinários e maior disponibilidade de alimentos que usualmente diversificam e melhoram a qualidade nutricional da dieta. Os efeitos do programa foram menores para famílias extremamente pobres / INTRODUCTION: Conditional cash transfer programs were implemented for the first time in Brazil in 1990. They were gradually expanded until 2003 and thereafter they were incorporated to the Bolsa Família Program. The assessment of the influence of conditional cash transfer programs on food consumption of Brazilian beneficiaries is scarce and the results of the studies are inconsistent. OBJECTIVES: To assess the impact of the Bolsa Família Program (hereafter identified as program) on household food availability in low-income families in Brazil. METHODS: The study analyzed data on a probabilistic sample of 55,970 households as part of the 2008-09 Household Budget Survey. The survey collected data on quantity and cost of all food and beverage purchased by the households during seven consecutive days. The per capita weekly expenditure and the daily energy of each food item were calculated. The assessment of the impact of the program was carried out for the group of low-income households (monthly per capita income up to R$ 210.00) and stratified for households with income above or below the median. Hereafter, these households are identified, respectively, as poor and extremely poor households. To assess the impact of the Program, food availability indicators were compared among of paired blocks of households, beneficiaries or non-beneficiaries of the program. These pairs were created based on the propensity score of each household to have beneficiary individuals. Using the propensity score matching method, pairs of blocks were created, which were homogeneous regarding many potential confounding variables for the association between the program and food acquisition. The per capita weekly expenditure and the daily energy consumption were compared considering all food items and three food groups based on the extent and the purpose of the industrial food processing applied to them: in natura or minimally processed foods, processed culinary ingredients and ready-to-eat products (processed or ultra-processed products). The comparisons between the blocks of beneficiaries and nonbeneficiaries households were carried out through paired \'t\' test. RESULTS: Compared to the non-beneficiaries, the beneficiaries households presented higher food expenditure (p=0.015), higher total energy availability (p=0.010) and higher availability of foods and culinary ingredients. There were no differences between groups regarding the expenditure and the availability of ready-to-eat products. Inside de group of foods, the expenditure and the availability of meat, tubers and vegetables were higher for the beneficiaries of the program. There were no differences regarding staple Brazilian foods like rice and beans. Similar results were observed for poor and extremely poor households, but the magnitude of the differences was lower for the households that were extremely poor. CONCLUSION: The impact of the Bolsa Família Program among low income families resulted in higher food expenditure, higher availability of foods and culinary ingredients and higher availability of foods that usually diversify and improve the diet quality. The effects of the Program seem to be lower for the extremely poor families
147

Déterminants du pronostic de la maladie coronarienne stable / Determinants of the prognosis of stable coronary artery disease

Sorbets, Emmanuel 18 September 2017 (has links)
Les patients coronariens stables ou stabilisés sont à haut risque d’évènements cardiovasculaires. Ils représentent une population hétérogène avec une présentation clinique, un terrain et un pronostic pouvant être extrêmement variables d’un patient à l’autre. Pourtant, d’après les recommandations internationales, tous doivent bénéficier d’une prise en charge relativement comparable basée sur des essais cliniques réalisés dans des sous-populations restreintes de patients stables et instables, pour la plupart anciens, et ne correspondant plus à la prise en charge actuelle des patients. Préciser les déterminants du pronostic de cette population, et notamment les stratégies thérapeutiques, est un enjeu majeur.Les antagonistes du système rénine-angiotensine (IEC/ARA2) font partie de l’arsenal médicamenteux de tout patient coronarien. Pourtant leur intérêt, en association aux antiagrégants plaquettaires et statines, est incertain chez les patients sans dysfonction ventriculaire gauche qui constituent un sous-groupe important parmi les patients stables.Le registre international REACH a évalué l’impact des IEC/ARA2 dans cette population avec 4 ans de suivi. La méthodologie statistique utilisée a été une analyse observationnelle avec ajustement ou avec appariement selon le score de propension. Il n’a pas été mis en évidence de bénéfice des IEC/ARA2 sur le critère de jugement principal composite associant décès cardiovasculaire – IDM – AVC, de même que sur le critère de jugement secondaire associant décès cardiovasculaire – IDM – AVC – Hospitalisation pour évènement athéro-thrombotique ou sur les critères tertiaires comprenant individuellement chacun des critères de jugement secondaire ainsi que sur la mortalité toute cause. Enfin il n’est pas ressorti non plus de bénéfice franc dans les sous-groupes d’analyse. Les résultats ont été concordants lorsque les analyses ont été réalisées pour les IEC seuls ou pour les ARA2 seuls, et ont été confortés par diverses analyses de sensibilité.Ces données méritent confirmation dans une cohorte indépendante. C’est l’un des objectifs du registre CLARIFY, registre de 32703 patients coronariens stables ou stabilisés, dont le suivi à 5 ans est terminé. Dans ce registre contemporain international, le taux global à 5 ans de mortalité toute cause a été de 7,9%, de mortalité non cardiovasculaire de 5% et de mortalité cardiovasculaire de 2,9%. Un évènement cardiovasculaire comprenant infarctus du myocarde (fatal ou non), angor instable, revascularisation coronaire par angioplastie ou pontage est survenu chez 15,9% des patients.Tout comme les IEC/ARA2, l’impact des bétabloquants dans la prise en charge du coronarien stable ou stabilisé, sans dysfonction ventriculaire est également controversé. Cette classe médicamenteuse est en cours d’évaluation dans CLARIFY. L’analyse tient compte du type de bétabloquant, de la dose prescrite, des éventuelles intolérances amenant à modifier leur utilisation, de la présence et de l’ancienneté d’un infarctus du myocarde et la fraction d’éjection ventriculaire gauche.CLARIFY a également pour objectif d’approfondir les déterminants du pronostic de la maladie coronarienne stable, avec une analyse spécifiquement focalisée sur la présence de symptômes angineux, d’ischémie myocardique et sur leur combinaison, en fonction de l’utilisation des méthodes de revascularisation myocardiques, pour mieux comprendre les mécanismes responsables des évènements cardiovasculaires et évoluer vers une prise en charge plus personnalisée. / Stable or stabilized coronary artery disease patients are at high risk for cardiovascular events. They represent a heterogeneous population. The clinical presentation, the context and the prognosis can be extremely variable from one patient to another. However, according to the international guidelines, those patients should be given a relatively comparable treatment based on clinical trials realized in restricted subpopulations of stable and unstable patients. Most of these trials are old, and no longer correspond to the current management. Specifying the determinants of the prognosis of this population, and in particular the therapeutic strategies, is a major challenge.The antagonist receptors of renin-angiotensin system (ACEI/ARB) are a part of the treatment of any coronary artery disease patient. Yet their interest in the prognosis of this population without left ventricular dysfunction in association with antiplatelet agents and statins is uncertain.The contemporary REACH registry has assessed the impact of ACEI/ARB in this population with a 4-year of follow-up. The statistical methodology used was based on the propensity score. After adjustment or matching with the propensity score, there was no benefit of ACEI/ARB on the primary endpoint of cardiovascular death - MI - stroke. No benefit was found on the secondary endpoint of cardiovascular death - MI - stroke - hospitalization for atherothrombotic events. No benefit was found on the tertiary criteria including individually each of the secondary endpoints and on any cause mortality. Finally,there was no clear benefit in the analyzes subgroups. These results were consistent when the analyzes were performed for ACEI alone or for ARB alone. They were also supported by sensitivity analyzes.These data should be confirmed or reversed in an independent cohort. This will be one of the many objectives of the CLARIFY registry, that enrolled 32,703 stable or stabilized coronary artery disease patients. The 5-year follow-up is complete. In this international contemporary registry, the overall 5-year rate of total mortality was 7.9%, non-cardiovascular mortality was 5% and cardiovascular mortality was 2.9%. A cardiovascular event including myocardial infarction (fatal or not), unstable angina, coronary revascularization by angioplasty or bypass surgery occured in 15.9% of patients.Like ACEI/ARB, the impact of betablockers on the management of stable or stabilized coronary artery disease without left ventricular dysfunction is also controversial. This drug class is being evaluated in CLARIFY. The analyzis takes into account the type of beta-blocker, the prescribed dose, any intolerance leading to changes in their use, the history of a myocardial infarction, and the left ventricular ejection fraction.CLARIFY will help to more define the determinants of the prognosis of stable coronary artery disease, with a more particular focus on symptomatic or not, ischemic or not, and revascularized or not, in order to better understand the mechanisms responsible for cardiovascular events, and evolve towards a more personalized and cost-effective care.
148

University Choice, Equality, and Academic Performance

Holzer, Susanna January 2009 (has links)
This thesis consists of three essays that examine issues on university attendance behavior, factorsof university completion, and the labor market value of a university diploma in Sweden. Essay [I] analyzes how the rapid expansion of higher education that increased the geographicalaccessibility to higher education in the 1990s affected university enrollment decisions amongvarious socioeconomic groups of young adults in Sweden. The empirical findings show that theprobability of enrollment in university education increases with accessibility to universityeducation. The results also indicate that accessibility adds to the likelihood of attending auniversity within the region of residence. Access to higher education more locally seems to havedecreased the social distance to higher education, meaning that the option of attending highereducation, as compared to entering the local labor market after upper secondary school, hasbecome a more common and a more natural alternative for more socioeconomic groups insociety. Essay [II] compares the performance of students in universities built before and after the largedecentralization and expansion of the higher educational system in Sweden, starting in the late1970s. Two outcome measures are used: (i) whether or not the student has obtained a degreewithin seven years after she initiated her studies; and (ii) whether or not she obtained 120 creditpoints (the requirement for most undergraduate degrees) within seven years. Controlling forseveral background variables as well as GPA scores in a binomial probit model, we show thatstudents at old universities are about 5 percentage points more likely to get a degree and about 9percentage points more likely to obtain 120 credit points. However, in an extended bivariatemodel where we consider selection on unobservables into university type, we cannot reject thepossibility of no difference in performance between the two university types. Essay [III] analyzes the labor market value of a university diploma (sheepskin) in Sweden. Incontrast to previous studies, this study only focuses on Swedish university students who havethree years of full time university education or more − where some have obtained a universitydegree, others not. The results show that for male students, the wage premium of possessing adegree, i.e. the sheepskin effect, is roughly 5-8 percent. For women, it is about 6-7 percent forthose who have completed four years of fulltime or more. For students who attended a moreprestigious university in the metropolitan areas in Sweden and majored in the natural sciences, asheepskin effect of roughly 13 percent for men and 22 percent for women is traced. However,this result did not hold among students who attended. Keywords: Higher education, university enrollment; university choice; accessibility; universitycompletion; selection bias; propensity score matching, sheepskin, human capital.
149

Analisi delle determinanti dell'abbandono scolastico: Il caso del settore della Further Education in Inghilterra. / An econometric analysis of the determinants of student dropout behavior: the case of further education sector in England

IRACI CAPUCCINELLO, ROSSELLA 13 July 2011 (has links)
Questo lavoro analizza le determinanti dell’abbandono scolastico nel settore della Further Education in Inghilterra. In particolare, il primo capitolo descrive i modelli teorici per l’analisi dell’abbandono scolastico e fornisce una revisione della letteratura sulle principali determinanti dell’abbandono scolastico. Il secondo capitolo si concentra sugli effetti della dimensione delle scuole e delle aree di insegnamento sulla probabilita’ di abbandono parziale e totale. Introduce il concetto di abbandono parziale, dimostrando che gli studenti che hanno abbandonato lo studio di alcune ma non tutte le materie a cui si erano iscritti reagiscono a cambiamenti nella dimensione delle scuole e delle aree di insegnamento in maniera simile agli studenti che abbandonano completamente gli studi. Il terzo capitolo analizza l’effetto causale dell’iscrizione a istituzioni di Further Education che sono state recentemente fuse sulla probabilita’ di non completare gli studi. Utilizziamo la tecnica del propensity score matching e controlliamo la qualita’ del matching e la sensibilita’ delle stime al fallimento dell’assunzione di unconfoundedness. I nostri risultati dimostrano che iscriversi ad una scuola oggetto di fusione riduce la probabilita’ di abbandonale gli studi. / This work analyses the determinants of dropout behavior in the Further Education sector in England. More specifically, the first chapter describe the theoretical framework for the analysis of student withdrawal and provides a review of the literature on the main determinants of dropout behavior. The second chapter focuses on the effect of college and programme area size on the probability of dropping out both partially and completely. It introduces the concept of partial dropout showing that students that dropped out of some modules but not all the ones they were enrolled on react to changes in college and programme area size similarly to the ones that dropped out completely. The third chapter analyses the causal effect of enrolling in a recently merged Further Education college on the probability of dropping out. We employ the propensity score matching approach and check the quality of our matching and the sensitivity of the estimates to the failure of the unconfoundedness assumption. Our findings show that enrolling in a merged college reduces the probability of dropping out.
150

Essays on the Effectiveness of Environmental Conservation and Water Management Policies

Mezzatesta, Mariano 2012 August 1900 (has links)
An awareness of the effect of agricultural production on the environment has led to the development of policies to mitigate its adverse effects. This dissertation provides analyses of agri-environmental policies designed to protect environmental assets, as well as analytical decision-making tools useful for conducting policy evaluations. The first essay employs propensity score matching techniques to estimate the additionality of federal agricultural conservation programs for six conservation practices for farmers in Ohio. Additionality is an important measure of the effectiveness of conservation programs in inducing an increase in the conservation effort of farmers. Results suggest that additionality is positive and statistically significant for all six conservation practices. However, while programs achieve positive additionality for all practice types, a comparison between conservation practices reveals that certain practice types achieve higher percent additionality than others. Such results, coupled with information on the environmental benefits obtained per practice, could prove useful to program managers for improving the effectiveness of conservation programs. The second essay develops a new methodology to decompose the additionality measure into the two effects induced by conservation programs: expansion versus the new adoption of conservation practices. To do so, the relative contributions of two types of farmers, prior-adopters and new-adopters, are estimated. Results of the decomposition reveal that the additionality for prior-adopters is not significant for all practice types. Instead, additional conservation effort comes from new-adopters adopting new practices. Second, decomposition estimates suggest that practice types with a greater fraction of enrolled farmers that are new-adopters achieve greater percent additionality than those with greater proportions of prior-adopters. This suggests that a farmers? history in conservation adoption has a significant influence on additionality levels. The final essay analyzes the effect of recent instream flow diversion-guidelines on agricultural water security and streamflows within a decentralized water management regime. Spatially-explicit economic and hydrologic models are integrated to evaluate the tradeoffs between salmon bypass-flows and agricultural water security for three different diversion-guidelines within a northern-California watershed. Results indicate that the most restrictive diversion-guideline provides the greatest protection of bypass-flow days within smaller watersheds; however, within larger watersheds protection is not as significant. Water security, however, decreases sharply under the strict and moderate diversion-guidelines, especially during dry years. Overall, results indicate that greater focus should be given to protecting streamflows in the smallest watersheds, and meeting human water needs during dry years, when agricultural water security is impacted the most.

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