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Causal Inference with Bipartite DesignsZhang, Minzhengxiong 11 1900 (has links)
Bipartite experiments have recently emerged as a focal point in causal inference. In these experiments, treatment is administered to one set of units, while outcomes of interest are gauged on a distinct set of units. Such experiments are especially valuable in scenarios where pronounced interference effects transpire between units on a bipartite network. For instance, in market experiments, designating treatment at the seller level and assessing outcomes at the buyer level (or vice-versa) can lead to causal models that more accurately reflect the inherent interference between buyers and sellers.
Although bipartite experiments can enhance the precision of causal effect estimations in specific contexts, it's imperative to conduct the analysis judiciously to avoid introducing undue bias through the network.
Drawing from the generalized propensity score literature, we demonstrate that it's feasible to achieve unbiased estimates of causal effects for bipartite experiments, given a conventional set of assumptions. Furthermore, we delve into the formulation of confidence sets with accurate coverage probabilities. By employing a bipartite graph from a publicly accessible dataset previously explored in bipartite experiment studies, we illustrate, via simulations, a notable reduction in bias and augmented coverage. / Statistics
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Cycling as a Cooperative Act: Observing cyclists' interactions with pedestrians at a zebra crossing in Stockholm / Cykling som ett samagerande: Observationer av cyklisters interaktioner med fotgängare vid ett övergångsställe i StockholmPrichard, Edward January 2020 (has links)
Cycling is undergoing a welcome renaissance, especially in urban contexts. However, there are tensions, in relation to pedestrians, which could negatively affect cycling’s growth. This thesis observes the social interactions and physical reactions of cyclists when co-present with pedestrians at a zebra crossing in central Stockholm. It uses both in-person and video observations with the films being processed using an observiaire, a relatively novel, quantitative method of capturing human behaviours. The results were explored using ideas on the practice of cycling and the street as a social space. It seems that cyclist’s momentum and desire to save energy is clearly important as cyclists will do almost anything except stop for a pedestrian. However, they also seem to have an ability and wish to cooperate. This could be using waves, nods, or shouts, but also invisible and physical communication, what I term peripheral communication. Overall, the cyclists observed were constantly balancing their desire for efficiency against their consideration of pedestrians.
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VOCABULARY INSTRUCTION IN FOUR MIDDLE SCHOOL CONTENT CLASSROOMS: A CASE STUDYHuck, Kelly Renee 28 March 2006 (has links)
No description available.
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Investigating the Validity of Observational Study Based on Electronic Medical Records and the Effectiveness of Perioperative Beta-Adrenoceptor Therapy to Reduce Postoperative Cardiac Events in Patients Undergoing Major Non-Cardiac SurgeryAn, Xuebei 24 August 2012 (has links)
No description available.
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Long-term follow-up of patients with anti-cyclic citrullinated peptide antibody-positive connective tissue disease: a retrospective observational study including information on the HLA-DRB1 allele and citrullination dependency / 抗環状シトルリン化ペプチド抗体陽性膠原病患者の長期追跡調査:HLA-DRB1アレルとシトルリン化依存性の情報を含む後ろ向き観察研究Iwasaki, Takeshi 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第23773号 / 医博第4819号 / 新制||医||1057(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 金子 新, 教授 杉田 昌彦, 教授 松田 秀一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
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Följsamheten kring basala hygienrutiner hos sjuksköterskor och undersköterskor på en medicinsk akutvårdsavdelning : En kvantitativ empirisk långtidsuppföljningKalajdzic, Benjamin, Bok, Daniel January 2019 (has links)
Tidigare forskning kring hygienrutiner har visat att följsamheten hos vårdpersonal är bristande samt att bristande följsamhet leder till ökad förekomst av vårdrelaterade infektioner (VRI). Syftet var att undersöka följsamheten kring basala hygienrutiner hos sjuksköterskor och undersköterskor samt jämföra hur följsamheten skiljer sig personalkategorierna emellan samt före och efter patientkontakt, på en medicinsk akutvårdsavdelning i södra Sverige under åren 2013–2018. Studien hade empirisk utformning. Data samlades in genom observationer och analyserades med stöd av Statistical Package for the Social Sciences (SPSS). Det som observerades var följsamhet till korrekt användning av handdesinfektion, handskar, platsförkläde/skyddsrock och rätt klädsel. Totalt gjordes 564 observationer mellan åren 2013–2018. Resultatet visar att det finns rum för förbättring i följsamhet. Överlag visar undersköterskor på en högre grad av följsamhet genom alla observerade år. Märkbar skillnad sågs mellan följsamhet till handdesinfektion före och efter patientkontakt, där följsamheten i sistnämnda var bristande. Vidare interventioner behövs för att förbättra följsamheten till basala hygienrutiner, minska risken för vårdrelaterade infektioner och höja patientsäkerheten. / Title: Compliance of nurses and assistant nurses to guidelines regarding basic hygiene routines in a medical intensive care unit: A quantitative long-term study. Previous research has shown that compliance to hygiene routines among healthcare professionals is inadequate and that inadequate compliance is linked to increased prevalence of healthcare-associated infections (HCAI). The aim of this study was to examine the compliance of nurses and assistant nurses to guidelines regarding basic hygiene routines and to make an occupational comparison before and after patient contact, in a medical intensive care unit in southern Sweden over a period of six years. The study had an empirical approach. Data was collected through observations and was analyzed using Statistical Package for the Social Sciences (SPSS). Observed aspects included compliance to correct usage of hand rub, plastic gloves, aprons as well as proper clothing. A total of 564 observations were made during the years 2013–2018. The result shows that there is room for improvements to compliance, with assistant nurses overall showing a higher rate of compliance throughout all observed years. Noticeable differences in compliance were found between hand rub usage before and after patient contact, with a lack of compliance in the latter. Further interventions are needed in order to improve compliance rates to guidelines regarding hygiene to prevent HCAI and increase patient safety.
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Interdisciplinär matematik : En observationsstudie av matematikens användning i fysik och kemi på gymnasieskolan / Interdisciplinary mathematics : An observational study on the use of mathematics in physics and chemistry in Swedish upper secondary schoolNilsson, Anton January 2019 (has links)
I dagens svenska gymnasieskola ska matematikundervisningen enligt läroplanen ge eleverna möjlighet att relatera matematiken till andra ämnen, då elever får en mer positiv bild av matematik när de inser att den finns överallt i deras vardagliga liv. Samtidigt är frågor som varför ska vi lära oss det här? och när kommer jag använda det här? vanligt förekommande under matematikundervisning, och elever har svårt att se meningen med matematikundervisningen. Syftet med denna studie är följaktligen att undersöka matematikens användning i ämnena fysik och kemi i gymnasieskolan. Mer specifikt; hur matematiska begrepp och metoder används och förklaras i fysik- och kemiundervisning. För att undersöka detta deltog fyra gymnasielärare (två i fysik och två i kemi) i en observationsstudie för att i en klassrumsmiljö identifiera och analysera om och hur matematiken används i de båda ämnena. Efter analys och kategorisering med hjälp av ett etablerat ramverk visade resultaten att samtliga deltagande lärare, i olika utsträckning, tillämpade interdisciplinär matematik i sin undervisning. Studien visade även att tillämpning av interdisciplinär matematik gav övervägande positiva resultat i fysik- såväl som kemiundervisningen. / In today's Swedish upper secondary school, the teaching of mathematics should, according to the curriculum, provide the students with the opportunity to relate mathematics to other subjects, since students get a more positive view of mathematics when they realize that it exists everywhere in their everyday life. Meanwhile, questions such as why should we learn this? and when will I use this? are frequently used during mathematics teaching, and students find it difficult to see the meaning in learning mathematics. Therefore, the purpose of this study is to investigate the use of mathematics in physics and chemistry in upper secondary school. More specifically; how mathematical concepts and methods are used as well as explained in physics and chemistry teaching. To investigate this, four upper secondary school teachers (two in physics and two in chemistry) participated in an observational study to identify and analyze if and how mathematics is used in the two subjects. After analysis and categorization with the help of an established framework, the results showed that all participating teachers, to varying degrees, applied interdisciplinary mathematics in their teaching. Moreover, the study showed that applying interdisciplinary mathematics yielded overwhelmingly positive results in physics and chemistry education.
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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 schizophreniaSarlon, 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.
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The role of perseverative negative thinking in predicting depression, anxiety and quality of life in people with coronary heart diseaseTrick, Leanne Victoria January 2017 (has links)
Depression is common in people with coronary heart disease (CHD) and is associated with worse physical outcomes. The nature of the causal association between CHD and depression, and the mechanism underpinning the association of depression with worse physical outcomes, remains unclear. Perseverative negative thinking may contribute to the development of depression in people with CHD. The aim of this thesis was to investigate the prospective association of perseverative negative thinking with depression, anxiety and worse physical outcomes in people with CHD, and to explore factors that may mediate this association. First, a systematic review identified 30 studies, of which the majority found an association between measures of perseverative negative thinking and subsequent depression, anxiety or emotional distress in people with long term conditions. Studies that controlled for covariates showed more mixed results, though the majority (15 / 25) still supported a significant association, with effects being small in magnitude. Findings were limited mainly to the association of rumination and/or catastrophizing with subsequent depression, and study quality was limited. Next, in an observational prospective cohort study 169 inpatients and outpatients with recent acute coronary syndrome (ACS) completed self-report assessments of rumination (Ruminative Responses Scale brooding subscale), worry (Penn State Worry Questionnaire), depression (Patient Health Questionnaire-8), anxiety (Beck Anxiety Inventory), and health-related quality of life (EuroQol-5D health-related quality of life, Seattle Angina Questionnaire) after hospitalisation, and at 2 month and 6 month follow-up. Additionally, assessments of potential mechanistic factors (social support, problem solving, instrumental behaviours and negative cognitive biases) were made. Baseline brooding was a significant independent predictor of depression at 6 months after controlling for the effects of important confounding variables, accounting for 2% of the variance. Findings suggested that the association of brooding with depression may be explained by deficits in problem solving ability. Rumination and problem solving may provide useful targets for the development of evidence-based interventions to improve depression among people with CHD, although the findings presented here fall short of proving a causal relationship. Future trials could be used to investigate the causal nature of the association of rumination and problem solving with depression in people with ACS.
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Controle dos níveis pressóricos em pacientes hipertensos nos municípios de São Paulo e Campinas: um grande estudo transversal / Blood pressure control in hypertensive patients in the municipalities of São Paulo and Campinas: a large cross-sectional studyCosta Filho, Francisco Flávio 27 July 2017 (has links)
INTRODUÇÃO: A hipertensão arterial sistêmica é a principal causa evitável de morbimortalidade cardiovascular no mundo contemporâneo, principalmente nos países de baixa renda. Avaliações populacionais das taxas de sucesso no controle dessa entidade precisam ser instituídas e continuamente realizadas. A compreensão do comportamento epidemiológico da hipertensão arterial sistêmica em coortes contemporâneas é importante para o planejamento de novas medidas de intervenção populacional. O presente estudo visa, como objetivo primário, a avaliar a eficácia no controle da hipertensão arterial sistêmica e a determinar preditores independentes associados ao melhor controle pressórico, em uma população de hipertensos sob tratamento medicamentoso derivada do Mutirão de Avaliação de Risco Cardiovascular. Como objetivo secundário, o estudo visa a avaliar a taxa de sujeitos sem diagnóstico prévio de hipertensão arterial sistêmica que apresentam a primeira medida pressórica alterada, assim como a determinar os preditores independentes desse achado. MÉTODOS: Estudo observacional, transversal, em que foram avaliados os participantes do Mutirão de Avaliação de Risco Cardiovascular dos municípios de São Paulo e Campinas. Foram incluídos nessa análise sujeitos com mais de 18 anos de idade, residentes nos municípios de São Paulo e Campinas. Para responder ao objetivo primário, foram analisados hipertensos com diagnóstico prévio e uso de medicamento anti-hipertensivo. Para responder ao objetivo secundário, foram analisados os sujeitos sem diagnóstico prévio de hipertensão e que não estavam em uso de medicações anti-hipertensivas. Utilizou-se análise multivariada para identificar preditores associados ao controle pressórico. RESULTADOS: Identificou-se 43.647 sujeitos hipertensos em uso de medicação, sendo que 40,9% destes estavam com níveis pressóricos controlados, considerando a meta de pressão arterial sistólica < 140 mmHg e pressão arterial diastólica < 90 mmHg. Entre os hipertensos não controlados, 42,5% apresentaram hipertensão arterial sistêmica em estágios II ou III (pressão arterial sistólica > 160 mmHg ou pressão arterial diastólica > 100 mmHg). Em análise multivariada, mostraram-se preditores independentes para melhor controle pressórico: idade < 60 anos [razão de chance (RC) 1,14, intervalo de confiança (IC) 95% 1,09-1,18], atividade física de moderada intensidade (RC 1,18, IC 95% 1,13-1,23), antecedente de doença cardiovascular (RC 1,09, IC 95% 1,04-1,13) e ingesta de frutas diariamente (RC 1,05, IC 95% 1,01-1,10). Mostraram-se preditores para controle pressórico inadequado: sexo masculino (RC 0,69, IC 95% 0,66-0,72), diabetes (RC 0,83, IC 95% 0,80-0,87), etnia negra (RC 0,88, IC 95% 0,83-0,94) ou parda (RC 0,92, IC 95% 0,87-0,97) em relação à branca e obesidade (RC 0,73, IC 95% 0,70-0,76). Entre 45.021 participantes sem diagnóstico prévio de hipertensão arterial sistêmica, 27,6% apresentaram a primeira medida pressórica elevada (pressão arterial > 140 x 90 mmHg). Mostraram-se preditores independentes para esse achado: sexo masculino (RC 2,05, IC 95% 1,96-2,15), idade > 60 anos (RC 1,88, IC 95% 1,78-1,98), etnia negra (RC 1,15, IC 95% 1,06-1,24) ou parda (RC 1,11, IC 95% 1,06-1,17) em relação à branca, obesidade (RC 2,08, IC 95% 1,98-2,19), diabetes (RC 1,09, IC 95% 1,01-1,18), antecedente de doença cardiovascular (RC 0,91, IC 95% 0,87-0,96) e atividade física de moderada intensidade (RC 0,87, IC 95% 0,83-0,92). CONCLUSÕES: Menos da metade dos hipertensos em tratamento estavam com seus níveis pressóricos controlados. Preditores independentes associados ao controle pressórico foram identificados, sendo três deles modificáveis. Estratégias populacionais devem ser implantadas para o controle efetivo desse importante fator de risco cardiovascular. / INTRODUCTION: Systemic arterial hypertension is the leading avoidable cause of cardiovascular morbidity and mortality in the contemporary world, mainly in low-income countries. Population evaluation of efficient strategies for blood pressure control should be implemented, and continually evaluated. Epidemiological understanding of systemic arterial hypertension in large cohorts plays important role for planning new interventions in the population level. The study objective is to evaluate the effectiveness of blood pressure control and to determine independent predictors, associated with better blood pressure control, in hypertensive patients on medical treatment from the Cardiovascular Risk Assessment in Sao Paulo and Campinas. The secondary objective is to access the rate of patients without previous diagnosis of systemic arterial hypertension in whom the blood pressure measurement is above recommended values, as well as determining independent predictors related with this finding. METHODS: The study design is an observational cross-sectional strategy in the municipalities of São Paulo and Campinas. Patients over the age of 18 living in São Paulo and Campinas, with previous diagnosis of systemic arterial hypertension and use of anti-hypertensive were included. Patients without previous diagnosis of hypertension and not using anti-hypertensive medication were also included. It was conducted a multivariate analysis to identify independent predictors associated with blood pressure control. RESULTS: We identified 43,647 hypertensive subjects on anti-hypertensive treatment. Of these 17,835 (40.9%) had controlled blood pressure levels, considering a target systolic blood pressure <140 mmHg and diastolic blood pressure < 90 mmHg. Among patients with uncontrolled hypertension, 42.5% were categorised as stage II or III hypertension (systolic blood pressure >=160 mmHg or diastolic BP >=100 mmHg). In a multivariate analysis, the following independent predictors were identified indicating better blood pressure control: age< 60 years [odds ratio (OR) 1.14, confidence interval (CI) 95% 1.09-1.18], moderate physical activity (OR 1.18, CI 95% 1.13-1.23), pre-existing atherosclerotic cardiovascular disease (OR 1.09, CI 95% 1.04-1.13) and daily consumption of fruit (OR 1.05, CI 95% 1.01-1.10). Predictors of poorer BP control were male sex (OR 0.69, CI 95% 0.66-0.72), diabetes mellitus (OR 0.83, CI 95% 0.80-0.87), African ethnicity (OR 0.88, CI 95% 0.83-0.94) or mixed African ethnicity (OR 0.92, CI 95% 0.87- 0.97) when compared to Caucasian ethnicity, obesity (OR 0.73, CI 95% 0.70-0.76). Among 45,021 participants without previous diagnosis of hypertension, 27.6% presented abnormal levels of blood pressure at the first measurement (BP >= 140/90 mmHg). The following independent predictors were identified: male sex (OR 2.05, CI 95% 1.96-2.15), age > 60 years (OR 1.88 CI 95% 1.78-1.98), African ethnicity (OR 1.15, CI 95% 1.06-1.24) or mixed African ethnicity (OR 1.11, CI 95% 1.06-1.17) when compared to Caucasian, obesity (OR 2.08, CI 95% 1.98-2.19), diabetes (OR 1.09, CI 95% 1.01-1.18), previous history of cardiovascular disease (OR 0.91, CI 95% 0.87-0.96) and moderate physical activity (OR 0.87, CI 95% 0.83-0.92). CONCLUSIONS: Less than half of hypertensive patients in treatment had controlled blood pressure. Independent predictors associated with blood pressure control were identified and three of them are modifiable. Population strategies should be implemented for effective control of this clinically relevant cardiovascular risk factor.
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