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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.
711

Uticaj demografskih faktora i karakteristika tumora na preživljavanje obolelih od karcinoma bronha u Vojvodini / Impact of demographic factors and tumor characteristics on the lung cancer patients survival in Vojvodina

Bokan Darijo 15 October 2020 (has links)
<p>&Scaron;irom sveta, karcinom bronha je i dalje vodeći po incidenci i mortalitetu, sa 2,1 milion novih slučajeva i predviđenih 1,8 smrtnih ishoda u 2018. godini. Karcinom bronha predstavlja skoro petinu (18,4%) svih smrtnih ishoda od karcinoma. Istraživanje je sprovedeno kao retrospektivna studija za period 2010-2016 godine. Svi podaci potrebni za sprovođenje ovog istraživanja direktno su prikupljeni iz zdravstvenog informacionog sistema i registra za karcinom bronha Instituta za plućne bolesti Vojvodine (IPBV), koji je referentna ustanova za pacijente sa karcinomom bronha za celu Autonomnu Pokrajinu Vojvodinu. Cilj rada je bio da se utvrdi uticaj demografskih i kliničko-patololo&scaron;kih karakteristika na ukupno vreme preživljavanja kod bolesnika sa karcinomom bronha, kao i da se izradi geoprostorna analiza incidencije i mortaliteta od karcinoma bronha na teritoriji Vojvodine. Podaci o broju novoobolelih i broju umrlih pacijenata potrebni za analizu incidencije i mortaliteta prikupljeni su od lokalnih Instituta za javno zdravlje za svaki od sedam okruga. Za potrebe analize overall survivall, survival rate ukupno je obuhvaćeno 8142 bolesnika lečenih u IPBV, od kojih je nakon provere uključujućih i isključujućih kriterijuma, u konačnu analizu u&scaron;lo njih 7540. Za potrebe analize incidencije i mortaliteta prikupljeni su podaci od lokalnih Instituta za javno zdravlje za svaki od sedam okruga i ukupno je uključeno 21915 pacijenata. Od ukupno 7540 bolesnika, bilo je 5456 (72,4%) mu&scaron;karaca i 2084 (27,6%) žena. Prosečna starost bolesnika iznosila je 63,4&plusmn;8,85 godina, Najveći broj bolesnika su bili pu&scaron;ači, njih 4911 (65,1%), biv&scaron;ih pu&scaron;ača je bilo 1995 (26,5%), dok je najmanje bilo nepu&scaron;ača, svega 634 (8,4%). Srednja vrednost indeksa paklo-godina (pack-years) iznosila je 50,57&plusmn;28,80. Posmatrano prema bračnom statusu, najvi&scaron;e bolesnika je bilo oženjeno/udato, njih 5348 (70,9%). Najveći broj bolesnika je ocenio svoj socioekonomski status kao osrednji, njih 4912 (65,1%). Broj bolesnika sa ECOG performans statusom 1 bio je 5679 (75,3%), njih 840 (11,1%) je imalo ECOG performans status 2, dok je ECOG performans status 0 imao 451 (6,0%) bolesnik. Najveći broj bolesnika bio je dijagnostikovan u IV stadijumu bolesti 3108 (41,2%), zatim u IIIB 1886 (25,0%), IIIA 1401 (18,6%), dok je u IA stadijumu dijagnostikovano najmanje bolesnika, njih 234 (3,1%). Najveći broj bolesnika imao je potvrđenu dijagnozu adenokarcinoma, njih 3342 (44,3%), zatim skvamoznog karcinoma 2472 (32,8%), mikrocelularnog karcinoma 1386 (18,4%). Od ukupnog broja bolesnika, tokom perioda praćenja preminulo je njih 6420 (85,1%), dok je 1120 (14,9%) bolesnika bilo živo. Prosečno vreme preživljavanja mu&scaron;karaca bilo je 17,116 meseci, a žena 23,193 meseca. Mu&scaron;karci oboleli od karcinoma bronha statistički značajno (p=0,000) kraće su živeli u odnosu na žene. Analiza kumulativnog preživljavanja bolesnika pokazala je da je postojala statistički značajna razlika u preživljavanju u odnosu na pol kod podtipova adenokarcinom (p=0,000), skvamozni karcinom (p=0,000) i mikrocelularni karcinom (p=0,001). Statistički značajna razlika u preživljavanju postojala je i u odnosu na starost, mesto stanovanja, tip tumora, stadijum bolesti, ECOG, pu&scaron;ački status i TNM stadijum bolesti (p=0,000). Ukupno jednogodi&scaron;nje preživljavanje obolelih od karcinoma bronha iznosilo je 32,5%, skvamoznog karcinoma 37,3%, adenokarcinoma 33,4% i mikrocelularnog karcinoma 20,9%. Ukupno trogodi&scaron;nje preživljavanje obolelih od karcinoma bronha iznosilo je 9,2%, skvamoznog karcinoma 10,8%, adenokarcinoma 10,7% i mikrocelularnog karcinoma 2,0%. Ukupno petogodi&scaron;nje preživljavanje obolelih od karcinoma bronha iznosilo je 5,0%, kod skvamoznog karcinoma 6,1%, adenokarcinoma 5,4% i mikrocelularnog karcinoma 1,3%. Ukupno jednogodi&scaron;nje preživljavanje obolelih od karcinoma bronha u 1A stadijumu iznosilo je 78,1%, u 1B stadijumu 73,2%, 2A stadijumu 70,4%, 2B stadijumu 52,1%, 3A stadijumu 42,3%, 3B stadijumu 28,3%, dok je u 4 stadijumu bolesti ukupno jednogodi&scaron;nje preživljavanje bilo 17,9%. Ukupno trogodi&scaron;nje preživljavanje obolelih od karcinoma bronha u 1A stadijumu iznosilo je 40,8%, u 1B stadijumu 37,5%, 2A stadijumu 31,2%, 2B stadijumu 21,6%, 3A stadijumu 9,7%, 3B stadijumu 5,5%, dok je u 4 stadijumu bolesti ukupno trogodi&scaron;nje preživljavanje bilo 2,9%. Ukupno petogodi&scaron;nje preživljavanje obolelih od karcinoma bronha u 1A stadijumu iznosilo je 32,1%, u 1B stadijumu 19,3%, 2A stadijumu 16,2%, 2B stadijumu 13,3%, 3A stadijumu 4,4%, 3B stadijumu 2,6%, dok je u 4 stadijumu bolesti ukupno petogodi&scaron;nje preživljavanje bilo 1,6%. Kao nezavisni prediktori preživljavanja izdvojeni su mu&scaron;ki pol, starost preko 60 godina, ECOG performans status veći od 2, pu&scaron;ačka navika, lo&scaron;iji socioekonomski status, stadijum IV bolesti, T4 status, M1b status i mikrokarcinom kao tip tumora (p=0,000). Incidencija karcinoma bronha za mu&scaron;karce iznosila je 118,9 na 100000 stanovnika, a za žene 43,3 na 100000 stanovnika. Standardizovana stopa incidencije karcinoma bronha za mu&scaron;karce iznosila je 65,4 na 100000 stanovnika, a za žene 21,7 na 100000 stanovnika. Prema okruzima je postojala statistički značajna razlika (p=0,001). Stopa mortaliteta od karcinoma bronha za mu&scaron;karce iznosila 125,1 na 100000 stanovnika, a za žene 43,8 na 100000 stanovnika. Standardizovana stopa mortaliteta od karcinoma bronha za mu&scaron;karce iznosila 67,6 na 100000 stanovnika, a za žene 20,9 na 100000 stanovnika. Prema okruzima je postojala statistički značajna razlika (p=0,001). Analizom prikupljenih podataka utvrđeno je da postoji statistički značajna razlika u ukupnom vremenu preživljavanja pacijenata sa dijagnostikovanim karcinomom bronha u odnosu na pol (p=0,000), starosnu dob (p=0,000), mesto stanovanja (p=0,014), pu&scaron;ački status (p=0,001), ECOG performans status (p=0,000) i socioekonosmski status (p=0,000). Postoji statistički značajna razlika u ukupnom vremenu preživljavanja pacijenata sa dijagnostikovanim karcinomom bronha u odsnosu na tip tumora (p=0,000), stadijum bolesti (p=0,000), T-deskriptor (p=0,000), N-deskriptor (p=0,000) i M-deskriptor (p=0,000). Utvrđeno je da ukupno jednogodi&scaron;nje preživljavanje obolelih od karcinoma bronha iznosi 32,5%, trogodi&scaron;nje preživljavanje obolelih od karcinoma bronha iznosi 9,2%, a petogodi&scaron;nje preživljavanje iznosi 5,0%. Utvrđeno je da su nezavisni prediktori preživljavanja mu&scaron;ki pol, starost preko 60 godina, ECOG performans status 2 i veći, pu&scaron;ačka navika, lo&scaron;iji socioekonomski status, stadijum IV bolesti, T4 status, M1b status i mikroculularni karcinom kao tip tumora. Urađena je analiza incidencije i mortaliteta od karcinoma bronha na teritoriji AP Vojvodine i utvrđeno je da postoje značajne regionalne razlike u incidenciji i mortalitetu od karcinoma bronha na teritoriji AP Vojvodine.</p> / <p>Worldwide, lung cancer remains the leading cause of cancer incidencije and mortality, with 2.1 million new lung cancer cases and 1.8 million deaths predicted in 2018. Methodology: For the purpose of this retrospective study we collected data of 21915 patients from seven Public Health Institutes, one for each district. This data was categorized by five-year age groups during 2010&ndash;2016. Survival analysis data of 8142 patients was collected from the Institute for Pulmonary Diseases of Vojvodina Hospital Information System and the Lung Cancer Registry. The primary objective was to determine the impact on overall survival by assessing demographic and clinical pathological characteristics in these patients. The secondary objective was to analyze the incidencije and mortality of lung cancer in the region of Vojvodina. Incidencije and mortality rates were directly age-standardized to the World and Europe Standard Population. A total of 7540 patients were eligible for the survival analysis, 5456 (72.4%) males and 2084 (27.6%) females. The average survival time, including all stages and cancer types was 17.1 months for men and 23.2 months for women (p = 0.000). There was statistically significant difference in survival time by gender in subtypes of adenocarcinoma (p = 0.000), squamous cell carcinoma (p= 0.000) and microcellular carcinoma (p = 0.001). Analysis showed significant difference in survival by age (p = 0.000), cancer type (p = 0.000), stage of the disease (p = 0.000), ECOG performance status (p = 0.000), smoking status (p = 0.001), TNM stage of disease (p = 0.000) and among districts (p = 0.014). Male gender (p = 0.000), age over 60 (p = 0.000), ECOG performance status 2 and greater (p = 0.000), smoking habit (p = 0.002), lower socioeconomic status (p = 0.000), stage IV of disease (p = 0.000) and small cell lung cancer as tumor type (p = 0.000) were identified as independent prognostic factors. One-year survival in 1A stage was 78.1%, in 1B stage 73.2%, 2A stage 70.4%, 2B stage 52.1%, 3A stage 42.3%, 3B stage 28.3 %, while in stage 4 was 17.9%. Three-year survival in 1A stage was 40.8%, in 1B stage 37.5%, 2A stage 31.2%, 2B stage 21.6%, 3A stage 9.7%, 3B stage 5.5 %, while in stage 4 was 2.9%. Five-year in 1A stage is 32.1%, in 1B stage 19.3%, 2A stage 16.2%, 2B stage 13.3%, 3A stage 4.4%, 3B stage 2.6 %, while in stage 4 was 1.6%. The incidencije rate was 118.9 per 100000 for males and 43.3 per 100000 for women. The standardized incidencije rate was 65.4 per 100000 for males and 21.7 per 100000 for females. There was a statistically significant difference by districts (p = 0.001). Mortality rate was 125.1 per 100000 for males and 43.8 per 100000 for females. The standardized mortality rate was 67.6 per 100000 for males and 20.9 per 100000 for females. There was also a statistically significant difference by district (p = 0.001). There was a statistically significant difference in overall survival by gender (p = 0.000), age (p = 0.000), place of residence (p = 0.014), smoking status (p = 0.001), ECOG performance status (p = 0.000), and socioeconomic status (p = 0.000). There was also a statistically significant difference in the overall survival by tumor type (p = 0.000), stage of disease (p = 0.000), T-descriptor (p = 0.000), N-descriptor (p = 0.000), and M-descriptor (p = 0.000). One-year survival rate was 32.5%, three-year survival was 9.2%, and five-year survival rate was 5.0%. Incidencije and mortality rates data were analyzed for the territory of Vojvodina, and it was found that there were significant regional differences.</p>
712

Estimation du bénéfice de survie à partir de méta-analyse sur données individuelles et évaluation économique. / Estimation of the survival benefit from individual participant data meta-analysis and economic evaluation.

Lueza, Béranger 30 September 2016 (has links)
Le bénéfice de survie restreint à un horizon temporel donné a été proposé comme mesure alternative aux mesures relatives de l’effet d’un traitement notamment dans le cas de non proportionnalité des risques de décès. Le bénéfice de survie restreint correspond à la différence des survies moyennes entre deux bras de traitement et s’exprime en nombre d’années de vie gagnées. Dans la littérature, cette mesure est présentée comme plus intuitive que le hazard ratio et plusieurs auteurs ont proposé son utilisation pour le design et l’analyse d’un essai clinique. Toutefois, ce n’est pas actuellement la mesure qui est utilisée de manière courante dans les essais randomisés. Cette mesure s’applique quelle que soit la distribution des temps de survie et est adaptée si l’hypothèse des risques proportionnels n’est pas respectée. De plus, le bénéfice de survie restreint peut être utilisé en évaluation médico-économique où la mesure d’un effet absolu est nécessaire (nombre d’années de vie gagnées pondérées ou non par la qualité de vie). Si l’on souhaite estimer le bénéfice de survie restreint à partir d’une méta-analyse sur données individuelles, se pose alors la question de prendre en compte l’effet essai dû à la structure hiérarchique des données. L’objectif de cette thèse était de comparer des méthodes statistiques d’estimation du bénéfice de survie restreint à partir de données individuelles d’une méta-analyse d’essais cliniques randomisés. Le point de départ a été une étude de cas (étude coût-efficacité) réalisée à partir des données de la Meta-Analysis of Radiotherapy in Lung Cancer. Cette étude a montré que les cinq méthodes d’estimation étudiées conduisaient à des estimations différentes du bénéfice de survie et de son intervalle de confiance. Le choix de la méthode d’estimation avait également un impact sur les résultats de l’analyse coût-efficacité. Un second travail a consisté à mener une étude de simulation pour mieux comprendre les propriétés des méthodes d’estimation considérées en termes de biais moyen et d’erreur-type. Enfin, la dernière partie de la thèse a mis en application les enseignements de cette étude de simulation au travers de trois méta-analyses sur données individuelles dans le cancer du nasopharynx et dans le cancer du poumon à petites cellules. / The survival benefit restricted up to a certain time horizon has been suggested as an alternative measure to the common relative measures used to estimate the treatment effect, especially in case of non-proportional hazards of death. The restricted survival benefit corresponds to the difference of the two restricted mean survival times estimated for each treatment arm, and is expressed in terms of life years gained. In the literature, this measure is considered as more intuitive than the hazard ratio and many authors have suggested its use for the design and the analysis of clinical trials. However, it is not currently the most used measure in randomized trials. This measure is valid under any distribution of the survival times and is adapted if the proportional hazards assumption does not hold. In addition, the restricted survival benefit can be used in medico-economic evaluation where an absolute measure of the treatment effect is needed (number of [quality adjusted] life years gained). If one wants to estimate the restricted survival benefit from an individual participant data meta-analysis, there is a need to take into account the trial effect due to the hierarchical structure of the data. The aim of this thesis was to compare statistical methods to estimate the restricted survival benefit from an individual participant data meta-analysis of randomized trials. The starting point was a case study (cost-effectiveness analysis) using data from the Meta-Analysis of Radiotherapy in Lung Cancer. This study showed that the five investigated methods yielded different estimates for the restricted survival benefit and its confidence interval. The choice of a method to estimate the survival benefit also impacted on cost-effectiveness results. Our second project consisted in a simulation study to have a better understanding of the properties of the investigated methods in terms of bias and standard error. Finally, the last part of the thesis illustrated the lessons learned from the simulation study through three examples of individual participant data meta-analysis in nasopharynx cancer and in small cell lung cancer.
713

Prognosis of cancer patients : input of standard and joint frailty models / Pronostic en cancérologie : apport des modèles à fragilité standards et conjoints

Mauguen, Audrey 28 November 2014 (has links)
La recherche sur le traitement des cancers a évolué durant les dernières années principalement dans une direction: la médecine personnalisée. Idéalement, le choix du traitement doit être basé sur les caractéristiques dupatient et de sa tumeur. Cet objectif nécessite des développements biostatistiques, pour pouvoir évaluer lesmodèles pronostiques, et in fine proposer le meilleur. Dans une première partie, nous considérons le problèmede l’évaluation d’un score pronostique dans le cadre de données multicentriques. Nous étendons deux mesuresde concordance aux données groupées analysées par un modèle à fragilité partagée. Les deux niveaux inter etintra-groupe sont étudiés, et l’impact du nombre et de la taille des groupes sur les performances des mesuresest analysé. Dans une deuxième partie, nous proposons d’améliorer la prédiction du risque de décès en tenantcompte des rechutes précédemment observées. Pour cela nous développons une prédiction issue d’un modèleconjoint pour un événement récurrent et un événement terminal. Les prédictions individuelles proposées sontdynamiques, dans le sens où le temps et la fenêtre de prédiction peuvent varier, afin de pouvoir mettre à jourla prédiction lors de la survenue de nouveaux événements. Les prédictions sont développées sur une série hospitalièrefrançaise, et une validation externe est faite sur des données de population générale issues de registres decancer anglais et néerlandais. Leurs performances sont comparées à celles d’une prédiction issue d’une approchelandmark. Dans une troisième partie, nous explorons l’utilisation de la prédiction proposée pour diminuer ladurée des essais cliniques. Les temps de décès non observés des derniers patients inclus sont imputés en utilisantl’information des patients ayant un suivi plus long. Nous comparons trois méthodes d’imputation : un tempsde survie moyen, un temps échantillonné dans une distribution paramétrique et un temps échantillonné dansune distribution non-paramétrique des temps de survie. Les méthodes sont comparées en termes d’estimationdes paramètres (coefficient et écart-type), de risque de première espèce et de puissance. / Research on cancer treatment has been evolving for last years in one main direction: personalised medicine. Thetreatment choice must be done according to the patients’ and tumours’ characteristics. This goal requires somebiostatistical developments, in order to assess prognostic models and eventually propose the best one. In a firstpart, we consider the problem of assessing a prognostic score when multicentre data are used. We extended twoconcordance measures to clustered data in the context of shared frailty model. Both the between-cluster andthe within-cluster levels are studied, and the impact of the cluster number and size on the performance of themeasures is investigated. In a second part, we propose to improve the prediction of the risk of death accountingfor the previous observed relapses. For that, we develop predictions from a joint model for a recurrent event anda terminal event. The proposed individual prediction is dynamic, both the time and the horizon of predictioncan evolve, so that the prediction can be updated at each new event time. The prediction is developed ona French hospital series, and externally validated on population-based data from English and Dutch cancerregistries. Its performances are compared to those of a landmarking approach. In a third part, we explore theuse of the proposed prediction to reduce the clinical trial duration. The non-observed death times of the lastincluded patients are imputed using the information of the patients with longer follow-up. We compared threemethods to impute the data: a survival mean time, a time sampled from the parametric distribution and atime sampled from a non-parametric distribution of the survival times. The comparison is made in terms ofparameters estimation (coefficient and standard-error), type-I error and power.
714

Student Performance in Higher Education: Ability, Class Attendance, Mobility and the Bologna Process

Lerche, Katharina 02 November 2016 (has links)
No description available.
715

Relation entre l’éducation des parents et la mortalité des enfants au Bénin

Sossa, Fortuné 09 1900 (has links)
Depuis plusieurs décennies, la réflexion sur le lien entre l'éducation des parents, en particulier celle de la mère sur la mortalité des enfants est demeurée une priorité de recherche et un enjeu majeur pour les organisations internationales et les décideurs politiques des pays en développement, confrontés à une mortalité plus élevée et un niveau d’éducation plus faible que dans les pays à revenu élevé. Toutefois, en dépit des arguments théoriques qui justifient l’importance de l’éducation de la mère sur la mortalité des enfants, bon nombre de travaux empiriques menés dans les pays en développement, et surtout ceux de l'Afrique subsaharienne, ont révélé une relation mitigée, indiquant parfois une atténuation ou une absence de relation. Les raisons avancées pour expliquer la divergence des résultats observés ont généralement trait aux différents contextes dans lesquels les études ont été réalisées et aux problèmes surtout d’ordre méthodologique et conceptuel résultant des données disponibles. En utilisant les données des Enquêtes Démographiques et de Santé (EDS) du Bénin, l'objectif principal de cette thèse était d’aboutir à une meilleure compréhension des aspects méthodologiques et conceptuels relatifs à l’association entre l’éducation des parents et la mortalité des enfants. Trois objectifs spécifiques sont examinés. Le premier objectif spécifique est consacré à la relation entre l’éducation de la mère et la mortalité des enfants de moins de cinq ans en 1991-1996 et 2001-2006 pour cerner d'une part, les différences de mortalité des enfants selon les catégories d'éducation de la mère à chacune des périodes et, d'autre part, la variation du risque de mortalité des enfants selon l'éducation de la mère entre ces deux périodes, considérant la baisse de mortalité des enfants qu'a connue le Bénin. Le deuxième objectif spécifique vise à cerner l'impact du niveau moyen de l’éducation des femmes de la communauté sur la mortalité des enfants. Dans le troisième objectif spécifique, nous évaluons dans quelle mesure l'éducation du père (variable souvent omise dans les études antérieures) contribue à l'amélioration de la survie des enfants. Les résultats de nos analyses sont présentés sous forme d’articles scientifiques. À l'aide des analyses multi-niveaux en temps discret, les résultats de l'article 1 montrent que le risque de mortalité des enfants de mères non éduquées n'est pas significativement différent de celui des enfants de mères qui n'ont pas complété le cycle primaire (1 à 5 ans de scolarité). Ce résultat a été observé aussi bien à l’EDS de 1996 qu'à celle de 2006. Le risque de mortalité des enfants de mères qui ont complété au moins le cycle primaire (6 années de scolarité et plus) est plutôt faible comparativement à celui des enfants de mères non éduquées. Les résultats montrent également que le différentiel du risque de mortalité des enfants de moins de cinq ans selon l'éducation de la mère n'a pas significativement changé entre les deux périodes d'enquêtes (1991-1996 et 2001-2006) au Bénin. S'agissant de l’impact du niveau moyen d’éducation des femmes de la communauté sur la mortalité des enfants (article 2), nos résultats confirment que le risque de mortalité des enfants de moins de cinq ans est moins élevé dans les communautés où la proportion de femmes éduquées est plus élevée, et ce, indépendamment de l'éducation de la mère. Plus intéressant, l'effet de l'éducation communautaire sur la mortalité des enfants de moins de cinq ans était plus important dans les communautés où l'offre de soins de santé est disponible et accessible. Quant à l'influence de l'éducation du père (variable souvent omise dans les précédentes études) (article 3), il ressort que le fait d'avoir un père éduqué réduit significativement le risque de mortalité des enfants. Par contre, son effet s'est révélé significatif seulement dans les communautés où l'offre de soins de santé est disponible et accessible. / The possible impact of parental education (especially that of the mother) on child mortality remains an important issue for researchers and a priority for international organizations and policy makers in developing countries, which face relatively higher mortality and lower levels of education. However, despite the theoretical arguments that justify the importance of mother's education for child mortality, many studies in developing countries, especially in sub-Saharan Africa, have revealed an ambiguous relationship, indicating sometimes an attenuation or lack of relationship. The lack of conclusive evidence is generally related to different contexts in which the studies were conducted and to methodological and conceptual problems resulting from the data used. Using DHS data from Benin, the main objective of this thesis is to contribute to a better understanding of the association between parental education and the under-five mortality. Specifically, this study examines: 1) the levels of child mortality by mother's education, focusing on differences between children born to women with no versus incomplete primary schooling (1-5 years of schooling) and changes in the estimated effects of mothers’ schooling across two time periods (1991-1996 and 2001-2006); 2) the extent to which education of women in the community influences the under-five mortality, and finally, 3) the impact of fathers’ schooling on under-five mortality. Using multilevel discrete-time logit models, we show in the first article that mothers with more than 5 years of schooling experience lower under-five mortality risk than mothers with no education. However, no significant difference in the under-five mortality risk between mothers with no education and those with incomplete primary education (1-5 years of schooling) is found for either of the two surveys. Furthermore, estimated effect of mothers’ schooling on under-five mortality did not change significantly between 1991-1996 to 2001-2006. In the second article, our results confirm that residing in a community where more women aged 15-49 have over 5 years of schooling is independently associated with lower under-five mortality. Interestingly, the impact of women's education in the community was more pronounced in areas with higher average child immunization rates. This suggests that the availability and accessibility of health services in the community is a possible mechanism through which the women's community-level education influences child survival. In the third article, we found that father's education is positively associated with the child survival, an effect that is attenuated when after controlling for the supply of health care services accessible in the community.
716

Duración de la tasa de interés de referencia en Perú durante el periodo 2004-2020

Hinojosa Aybar, Jerson Jesús 27 June 2020 (has links)
En el presente documento se emplean modelos de supervivencia para analizar la duración en que la tasa de interés de referencia, utilizada por el Banco Central de Reserva del Perú como instrumento de política monetaria, permanece sin cambios. Para el análisis se emplean modelos no paramétricos y paramétricos, permitiendo la naturaleza de datos censurados por la derecha y covariables no constantes en el tiempo. Para el análisis de supervivencia del modelo no paramétrico, se emplea el estimador Kaplan-Meier para formar las funciones de supervivencia y de riesgo. Por otro lado, en cuanto al análisis de los modelos paramétricos, se comparan dichas funciones estimadas bajo una función Exponencial, Weibull y Log-logística. Para ello, se emplea como covariables la variación mensual y anual del producto bruto interno (PBI), la inflación, la tasa de interés de referencia, el desempleo y el tipo de cambio. Se estiman 24 modelos y se selecciona el mejor de acuerdo con la significancia de las variables y el criterio de información de Akaike. Se obtiene que tanto para el análisis no paramétrico y paramétrico, la probabilidad de que la tasa de interés de referencia permanezca sin cambios es cada vez menor a lo largo del tiempo. Además, en el modelo paramétrico bajo la distribución Weibull y Loglogística (distribución escogida como preferida) se obtienen como variables significativas la inflación, el producto bruto interno y el nivel de la tasa de interés de referencia; sin embargo, al emplear la distribución Exponencial, el producto bruto interno no es significativo. / In the present document, survival models are used to analyze the duration of the reference interest rate, while it remains constant, used by the Central Reserve Bank of Perú as its monetary policy instrument. For the analysis, both nonparametric and parametric models are estimated, allowing the nature for right-censoring of the data and time-varying covariates. In case of non-parametric model, Kaplan-Meier estimator is used to model survival and hazard functions. In case of parametric models, the survival and hazard functions are compared under an Exponential, Weibull and Log-Logistical functions. The monthly and annual variation of the gross domestic product, the inflation rate, the interest rate, the unemployment rate and the exchange rate are used as covariates. Twenty-four models are estimated. The best one is selected according to the significance of the covariate’s ant Akaike information criterion. The results show that for both non-parametric and parametric models, the probability of a constant interest rate remains unchanged is less over the time. Furthermore, in the parametric model under Weibull distribution and Log-Logistical distribution (preferred distribution), inflation rate, gross domestic product and the interest rate are obtained as significant variables; however, the gross domestic product isn´t significant under Exponential distribution. / Trabajo de investigación
717

Calculating control variables with age at onset data to adjust for conditions prior to exposure

Höfler, Michael, Brueck, Tanja, Lieb, Roselind, Wittchen, Hans-Ulrich January 2005 (has links)
Background: When assessing the association between a factor X and a subsequent outcome Y in observational studies, the question that arises is what are the variables to adjust for to reduce bias due to confounding for causal inference on the effect of X on Y. Disregarding such factors is often a source of overestimation because these variables may affect both X and Y. On the other hand, adjustment for such variables can also be a source of underestimation because such variables may be the causal consequence of X and part of the mechanism that leads from X to Y. Methods: In this paper, we present a simple method to compute control variables in the presence of age at onset data on both X and a set of other variables. Using these age at onset data, control variables are computed that adjust only for conditions that occur prior to X. This strategy can be used in prospective as well as in survival analysis. Our method is motivated by an argument based on the counterfactual model of a causal effect. Results: The procedure is exemplified by examining of the relation between panic attack and the subsequent incidence of MDD. Conclusions: The results reveal that the adjustment for all other variables, irrespective of their temporal relation to X, can yield a false negative result (despite unconsidered confounders and other sources of bias).
718

Termoregulace mravenců rodu Formica, konflikt jedince versus kolonie / Thermoregulation in ant genus Formica, an individual vs. colony conflict

Kadochová, Štěpánka January 2017 (has links)
This thesis deals with thermoregulation in red wood ants, in Formica rufa group. Our aim was to better understand the mechanisms by which red wood ants maintain thermal homeostasis in their nests. Red wood ants are known to keep high and stable temperatures in their nests from spring to autumn. Most emphasis is placed on the role of the nest mound as a solar collector or on a heat production by microbial community present in the nest material. However, some researchers believe that wood ants are able of active nest thermoregulation in which they can affect the nest temperature by behavioural reactions, mainly by sun basking, increased metabolic heat production or heat transport. The thesis consists of three research articles. The first one is focused on the timing of thermoregulation in red wood ants, the second one investigates in more detail one specific aspect of red wood ant thermoregulation - a sun basking behaviour. These two papers provide data from long-term field observations and experiments. The last paper is based on laboratory experiments where we tested a hypothesis resulting from field observations. Thanks to the field research we found out that ant activity (traffic on ant trails) significantly correlates with nest temperature; once the activity decreased the thermal homeostasis...
719

Bostad till salu : En analys av tid-till-försäljning på Uppsalas bostadsmarknad

Eriksson, Fabian, Ajdert, Alexander January 2022 (has links)
Denna uppsats har undersökt tid-till-försäljning på Uppsala kommuns bostadsmarknad för lägenheter under året 2021. För att analysera tid-till-försäljning har metoder från överlevnadsanalys använts. Överlevnadsfunktionen och den kumulativa hasardfunktionen har skattats med Kaplan-Meier-skattningen och Nelson-Aalen-skattningen. Därutöver har tre modeller skattats; en Cox proportionell hasardmodell och två 'Accelerated Failure Time'-modeller varav en var en Weibullmodell och en var en Loglogistiskmodell. Resultaten indikerar att tid-till-försäljning har en hög hasard efter två veckor på marknaden varefter en avtagande hasard. Resultaten indikerar att kovariat har en statistisk signifikant effekt på tid-till-försäljning. Grafiska tester indikerar att antagandet om proportionalitet för Cox proportionella hasardmodell och antagandet om den underliggande hasardfunktionen för Weibullmodellen är orimliga. Antagandet om den underliggande hasardfunktionen för loglogistiskamodellen verkar rimlig. Goodness-of-fit indikerar att Weibullmodellen och loglogistiskamodellen var mer välanpassade till datamaterialet än Cox proportionella hasardmodell. / This bachelor's thesis has investigated time-to-sale on the Uppsala municipality property market for apartments during 2021. Analysis has been performed utilising methods from survival analysis. Both the survival function and cumulative hazard function were estimated using the Kaplan-Meier estimate and the Nelson-Aalen estimate respectively. Furthermore, three models were estimated; a Cox Proportional Hazards model as well as two Accelerated Failure Time models of which one was a Weibullmodell and the other was a loglogistic model. The results indicate that time-to-sale has a high hazard after two weeks on the market followed by a decreasing hazard. The results also indicate that covariates have a statistically significant effect on time-to-sale. Graphical tests indicate that the assumption of proportionality for the Cox Proportional Hazards model and the assumption of the underlying hazard function for the Weibullmodell are unreasonable. The assumed hazardfunction of the loglogistic model was found to be reasonable. Goodness of fit indicates that the Weibull model and loglogistic model were a better fit to the data than the Cox proportional Hazardsmodel.
720

Terapijski i prognostički značaj gustine tumorskih pupoljaka kod reseciranih sinhronih i metahronih jetrenih metastaza kolorektalnog karcinoma / Therapeutic and prognostic significance of tumor bud density in resected synchronous and metachronous liver metastases in colorectal cancer

Petrović Nemanja 11 September 2020 (has links)
<p>Tumorsko pupljenje (TP) u karcinomu je morfolo&scaron;ki fenomen koji predstavlja pojavu pojedinačnih ili malih grupa dediferentovanih tumorskih ćelija koje se na invazivnom frontu karcinoma odvajaju od glavne tumorske mase. Kod metastatskog kolorektalnog karcinoma (KRK) definitivno ne možemo odrediti pravi doprinos TP. Cilj je bio da se ispita terapijski patohistolo&scaron;ki odgovor na primenjeni hemioterapijski režim, prognostički i nezavisni negativni značaj TP , kao i korelacija TP i terapijskog odgovora histolo&scaron;ke regresije kod R0 reseciranih sinhronih i metahronih jetrenih metastaza KRK, koji su primali polihemioterapije po protokolu Folfox 4, sa i bez VEGF inhibitora &ndash; bevacizumaba (AV).&nbsp; Studija je prospektivno &ndash; retrospektivna i obuhvata 77 bolesnika oba pola, uzrasta preko 18 godina, sa patohistolo&scaron;ki verifikovanim jetrenim metastazama KRK, koji su operisani u Institutu za onkologiju Vojvodine u periodu od 1. maja 2007. do 1. juna 2017. godine. Od ukupno 120 bolesnika, njih 77 je ispunjavalo sledeće kriterijume: da je histolo&scaron;ki dokazan metastatski adenokarcinom kolorektuma sa R0 resekcijom i da su preoperativno dobijali HT sa biolo&scaron;kom terapijom ili bez nje. Bolesnike smo podelili u dve grupe: KRK &ndash; sinhrona metastatska bolest i KRK &ndash; metahrona metastatska bolest. Nakon selekcije bolesnika, rađena je mikroskopska analiza rutinskih histolo&scaron;kih i imunohistohemijskih preparata i određivana je gustina TP, histolo&scaron;ka regresija prema mTRG bodovanju komparirala se sa radiolo&scaron;kim odgovorom po RECIST-u. Događaji od interesa u kliničkom toku bolesti jesu progresija nakon hirur&scaron;kog zahvata jetrenih metastaza i ukupno preživljavanje u periodu od 24 meseca. Nema statistički značajne patohistolo&scaron;ke razlike u učestalosti lo&scaron;ijeg terapijskog odgovora (mTRG 3 &ndash; 5) u odnosu na bolji terapijski odgovor (mTRG 1, 2) između bolesnika sa sinhronom i metahronom metastatskom bole&scaron;ću KRK, koji su lečeni hemioterapijskim protokolom Folfox4: 13 (76,5%) vs. 13 (72,2%); p = 0,774. Kod bolesnika sa sinhronim metastazama KRK, lečenih hemioterapijskim protokolom Folfox 4, postoji statistički značajna razlika u učestalosti preživljavanja tokom dve godine, i to kod bolesnika sa malom u odnosu na one sa velikom gustinom TP: 10 (90,9%) vs. 5 (55,6%); p = 0,049. Kod tih bolesnika, lečenih hemioterapijskim protokolom Folfox4/AV, postoji statistički značajna razlika u učestalosti preživljavanja tokom dve godine, i to kod bolesnika sa malom u odnosu na one sa velikom gustinom TP: 9 (100%) vs. 6 (33,3%); p = 0,048. Kod bolesnika sa metahronim metastazama KRK lečenih hemioterapijskim protokolom Folfox4, sa i bez AV, nema statistički značajne razlike u učestalosti preživljavanja tokom dve godine u odnosu na gustinu TP. Kod bolesnika sa sinhronim i metahronim metastazama KRK nema statistički značajne razlike u učestalosti lo&scaron;ijeg histolo&scaron;kog odgovora na terapiju (mTRG 3 &ndash; 5) kod onih sa malom u odnosu na one sa velikom gustinom (TP): (8 (50%) vs. 15 (78,9%); p = 0,072 i TP: 8 (80%) vs. 13 (72,2%); p = 0,649). Kod bolesnika sa sinhronim metastazama KRK lečenih hemioterapijskim protokolom Folfox4, sa i bez AV, postoji statistički značajna razlika u učestalosti preživljavanja tokom dve godine u odnosu na gustinu TP. Takođe, kod tih bolesnika velika gustina TP je nezavistan negativan faktor prognoze u odnosu na date terapijske režime, &scaron;to se vidi u preživljavanju tokom dve godine.</p> / <p>Tumor budding (TB) in cancer is a morphological phenomenon representing the appearance of single or small groups of dedifferentiated tumor cells that separate from the main tumor mass on the invasive front of cancer. In metastatic colorectal cancer (MCC), the true contribution of TB cannot be determined. The aim was to investigate the therapeutic pathohistological response to the applied chemotherapy, the prognostic and independent negative significance of TB, as well as the correlation of TB and the therapeutic response of histological regression in R0 resectable synchronous and metachronous liver metastases of MCC receiving polychemotherapy according to the Folfox 4 protocol, with and without VEGF inhibitors - bevacizumab (AV). The research was conducted as a prospective &ndash; retrospective study that included 77 patients of both sex, over 18 years of age, with pathohistologically verified MCC liver metastases, who underwent surgery at the Institute of Oncology of Vojvodina from 1st May 2007 until 1st June 2017. From 120 patients, 77 patients met the following criteria: they had histologically proven metastatic colorectal adenocarcinoma with R0 resection and also received preoperative chemotherapy with or without biological therapy. The patients were divided into two groups: MCC - synchronous metastatic disease and MCC - metachronous metastatic disease. After the patient selection, microscopic analysis of routine histological and immunohistochemical preparations was performed, the density of TB was determined, and the histological regression according to mTRG scoring was compared with a radiologic response according to the RECIST. The events of interest in the clinical course of the disease were the progression of hepatic metastases after surgery and overall survival during 24 months. There is no statistically significant pathohistological difference in the incidence of worse therapeutic response (mTRG 3 - 5) compared to the better therapeutic response (mTRG 1, 2) between patients with synchronous and metachronous MCC who were treated with the Folfox4 chemotherapy protocol: 13 (76.5%) vs. 13 (72.2%); p = 0.774. In patients with synchronous MCC metastases treated with the Folfox 4 chemotherapy protocol, there was a statistically significant difference in the survival rates during two years particularly in patients with low versus high TB density: 10 (90.9%) vs. 5 (55.6%); p = 0.049. In those patients who were treated with the Folfox4 / AV chemotherapy protocol, there was a statistically significant difference in survival rates during two years particularly in patients with low TB density in reference to those with high: 9 (100%) vs. 6 (33.3%); p = 0.048. In patients with metachronous MCC metastases who were treated with the Folfox4 chemotherapy protocol, with and without AV, there was no statistically significant difference in survival rate during two years when referring to the TB density. In patients with synchronous and metachronous metastases, MCC has no statistically significant difference in the incidence of worse histological response to therapy (mTRG 3 - 5) in patients with low TB density versus the ones with high density (TB): (8 (50%) vs. 15 (78.9%); p = 0.072 and TP: 8 (80%) vs. 13 (72.2%); p = 0.649). In patients with synchronous MCC metastases who were treated with the Folfox4 chemotherapy protocol, with and without AV, there is a statistically significant difference in survival rates during a two-year follow up when referring to the TB density. Also, the high density of TB is an independent negative prognostic factor in these patients in reference to the given therapeutic regimens, as seen in the two-year survival rate.</p>

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