Abstract Estrogen replacement therapy (ERT) has been associated with favorable effects on risk factors for atherosclerosis. In observational studies ERT was also suggested to reduce the risk of cardiovascular disease in postmenopausal women, but the cardioprotective role of estrogen has been challenged after negative results in randomized trials. However, the mechanisms of estrogen action in atherosclerosis development are only partially known. In order to investigate the regulation of plasma low-density lipoprotein (LDL) cholesterol in postmenopausal women and the effects of ERT on cholesterol and glucose metabolism and blood pressure, 79 hysterectomized, non-diabetic postmenopausal women were randomized in a double-blind, double-dummy study to receive either peroral estradiol valerate (2 mg/day) or transdermal 17β-estradiol gel (1 mg estradiol/day) for six months. At baseline the level of LDL cholesterol was related to body mass index, the fractional catabolic rate (FCR) and the production of LDL apolipoprotein B (apo B), but not to cholesterol absorption efficiency. Both peroral and transdermal ERT decreased plasma total and LDL cholesterol, while high-density lipoprotein cholesterol and triglycerides increased only in the peroral group. The LDL-lowering response was related to changes in estrogen levels, which presumably enhance LDL receptor activity shown as an increase in FCR for LDL apo B. In contrast, the determined genetic factors, apo E phenotype, EcoRI and XbaI polymorphisms of the apo B gene and polymorphism of 7α-hydroxylase gene, were not significant in regulation of LDL cholesterol, neither did they modify the response of ERT in these postmenopausal women. Similar outcomes were observed with both peroral and transdermal ERT as regards glucose metabolism and blood pressure. The overall effect of ERT on glucose tolerance was found to be neutral. Blood pressure decreased among non-hypertensive subjects on both estrogens, which could be related, at least in part, to the alterations in vasoactive peptides. The data of the present study suggest an overall favorable effect of both peroral and transdermal estrogen on common cardiovascular risk factors. However, the clinical significance of these findings in the prevention of cardiovascular diseases needs to be proven in long-term, randomized trials.

Ce travail porte sur le comportement mécanique de la cupule acétabulaire de prothèse de hanche dans le milieu osseux. Un intérêt particulier est porté au développement d'une méthode d'analyse de signaux d'impacts visant à caractériser les propriétés biomécaniques de l'interface entre la cupule acétabulaire et l'os périacétabulaire. Dans un premier temps, l'insertion de la cupule par impacts reproductibles est étudiée expérimentalement. Il est démontré que les signaux de force des impacts sont sensibles aux conditions d'insertion de l'implant acétabulaire. Un modèle analytique empirique considérant une configuration poinçon plat est utilisé pour modéliser les conditions de contact entre l'os et l'implant. La stabilité de l'implant acétabulaire est ensuite évaluée dans différentes configurations osseuses. Une analyse des signaux d'impact permet d'estimer cette stabilité. Dans un deuxième temps, un marteau est instrumenté avec un capteur de force et utilisé pour enregistrer les signaux de force des impacts. La méthode d'analyse des signaux est adaptée et permet d'évaluer la stabilité primaire de l'implant acétabulaire. Pour permettre le transfert de l'approche vers une application clinique, une étude cadavérique est ensuite réalisée. Il est montré que la méthode est utile pour prévoir la stabilité primaire de la cupule acétabulaire dans des hanches cadavériques. Le troisième volet de cette thèse est composé d'études de simulation numérique pour mieux comprendre le comportement mécanique de la cupule acétabulaire. Un modèle est développé pour investiguer les procédés dynamiques ayant lieu lors de l'impaction de la cupule acétabulaire et pour estimer le potentiel de la méthode d'analyse d'impacts pour déterminer les conditions d'insertion de la cupule acétabulaire. Différentes conditions d'interférence et différentes vitesses d'impaction sont considérées. Il est montré que les signaux d'impacts sont sensibles à surface de contact entre l'os et l'implant. Un second modèle étudie l'influence des propriétés mécaniques de l'os périacétabulaire au comportement mécanique de la cupule / While hip arthroplasty has become a common surgical procedure, failures still happen due to inadequate mechanical behavior of the prosthesis. This work studies the behavior of the acetabular cup (AC) implant within bone tissue and develops an impact analysis method to assess its insertion conditions. In the first part, AC insertion within bovine bone tissue are performed using reproducible mass drops. The impact force signals are recorded and are shown to be sensitive to insertion conditions of the AC implant. An empirical analytical model considering a flat punch configuration to model the bone-implant contact conditions is used to understand the variations of the signals. The AC implant tangential stability is further evaluated for different bone cavity configurations. An impact signals analysis enables to assess the AC implant primary stability in vitro. In the second part, a hammeris instrumented with a force sensor and is used to record the impacts force signals. The impact signals analysis allows to evaluate the AC implant stability. In order to transfer the approach to a situation closer to the clinical application, tests are then realized with cadaveric hips. The method is found useful to predict the AC implant stability ex vivo. In the third part, finite element models are developed to improve the understanding of the AC implant mechanical behavior within bone tissue. A model investigates the dynamic processes occurring during the AC implant impaction. The impact signals analysis allows to evaluate the bone implant contact area. A second model studies the influence of the peri-implant anisotropic bone mechanical properties on the mechanical behavior of the AC implant. By coupling experimental and numerical approaches, this work provides new features concerning the mechanical processes responsible for the AC implant stability. Moreover, the feasibility of a medical device that could assess peroperatively the AC implant stability is proved

Philosophiae Doctor - PhD / End stage renal disease (ESRD), a more severe form of kidney disease, is considered to be a complex trait that may involve multiple processes which work together on a background of a significant genetic susceptibility. Black Africans have been shown to bear an unequal burden of this disease compared to white Europeans, Americans and Caucasians. Despite this, most of the genetic and epidemiological advances made in understanding the aetiology of kidney diseases have been done in other populations outside of sub-Saharan Africa (SSA). Very little research has been undertaken to investigate key genetic factors that drive ESRD in Africans compared to patients from rest of world populations. Therefore, the primary aim of this Bioinformatics thesis was twofold: firstly, to develop and apply a whole exome sequencing (WES) analysis pipeline and use it to understand a genetic mechanism underlying ESRD in a South African population of mixed ancestry. As I hypothesized that the pipeline would enable the discovery of highly penetrate rare variants with large effect size, which are expected to explain an important fraction of the genetic aetiology and pathogenesis of ESRD in these African patients. Secondly, the aim was to develop and set up a multicenter clinical database that would capture a plethora of clinical data for patients with Lupus, one of the risk factors of ESRD. From WES of six family members (five cases and one control); a total of 23 196 SNVs, 1445 insertions and 1340 deletions, overlapped amongst all affected family members. The variants were consistent with an autosomal dominant inheritance pattern inferred in this family. Of these, only 1550 SNVs, 67 insertions and 112 deletions were present in all affected family members but absent in the unaffected family member. Following detailed evaluation of evidence for variant implication and pathogenicity, only 3 very rare heterozygous missense variants in 3 genes COL4A1 [p.R476W], ICAM1 [p.P352L], COL16A1 [p.T116M] were considered potentially disease causing. Computational relatedness analysis revealed approximate amount of DNA shared by family members and confirmed reported relatedness. Genotyping for the Y chromosome was additionally performed to assist in sample identity. The clinical database has been designed and is being piloted at Groote Schuur medical Hospital at the University of Cape Town. Currently, about 290 patients have already been entered in the registry. The resources and methodologies developed in this thesis have the potential to contribute not only to the understanding of ESRD and its risk factors, but to the successful application of WES in clinical practice. Importantly, it contributes significant information on the genetics of ESRD based on an African family and will also improve scientific infrastructure on the African continent. Clinical databasing will go a long way to enable clinicians to collect and store standardised clinical data for their patients.

Master of Science in Veterinary Biomedical Science / Department of Clinical Sciences / Robert L. Larson / The selection of young replacement animals can have a significant impact on beef herd reproductive performance. Replacement heifers can be utilized to improve reproductive performance by replacing mature animals that failed to meet the production with young, cycling heifers that can have the potential of improving the reproductive momentum of a herd. The use of yearling bulls in natural breeding herds has the advantage of shortening the generational interval of the herd and has the potential of reducing the cost per cow exposed as additions to the bull battery. This thesis involves two studies that investigated methods used for the selection of peripubertal replacement animals in beef herds. The first study evaluated the ability of the novel Ready-Intermediate-Problem (RIP) replacement heifer evaluation matrix to classify heifers into groups that allow producers to select for replacements that meet production goals. Beef heifers (n=341) were classified according to the RIP matrix guidelines and then exposed to AI breeding, bull breeding, or a combination of both as per the management plans for each participating herd. Following breeding season the heifers were evaluated to determine pregnancy status, pregnancy status to single AI exposure, days bred, and the number of 21 day cycles needed during breeding season to become pregnant. After breeding season, 298 (87%) of the heifers were pregnant, 204 (68%) of which became pregnant in the first 21 days of the breeding season. Probability of overall pregnancy and pregnancy after single AI exposure was not significantly associated with RIP classification. There was a significant interaction in RIP classification by 21 day cycle. The second study was a retrospective study using BSE result data to determine the proportion of yearling beef bulls that are classified as satisfactory potential breeders when reevaluated after failing their initial breeding soundness evaluation (BSE) and to identify any predictive factors at initial BSE for satisfactory performance at revaluation. The study included 2,805 beef bulls between 11 and 14 months of age at first BSE evaluated at KABSU from 2006 to 2014. Generalized linear mixed models were created to assess potential associations among breed, age, and interaction between breed and age and passing the initial evaluation and identify predictive factors for risk of passing BSE after initial failure. The majority (93%) of the study bulls passed one of up to three BSEs. There was a significant interaction between age and breed of bull at initial BSE. Identification of suitable peripubertal replacement animals that will improve herd reproductive performance remains a challenge for producers. There are several factors that can affect replacement animals’ ability to perform according to expectations at the beginning of the breeding season. Classification of heifers into categories that can predict performance during breeding season with reasonable confidence can assist producers in identifying heifers that complement the reproductive performance goals of the herd. Utilizing BSE to identify bulls that have adequate semen quality as well as other traits important for breeding soundness is similarly important in reducing the risks of using young bulls for breeding.

Population ageing is one of the most important current problems in developed countries. The goal of my work is the analysis of economic and social problems occasioned by population ageing, population prognosis and the possibility of compensation a population loss and changes in age structure through replacement migration. This is all in the Czech Republic. For my work I will use readily available information databases, mainly the database provided by Czech Statistical Office and the databases of relevant ministries in the Czech Republic. At first I will make demographic predictions using a component method without migration and then I will use replacement migration to compensate a population loss and changes in selected demoeconomic characteristics. The contribution of my work is in the concretization of methodology for calculating the replacement migration and in the results obtained from this study, which will show feasibility of this concept in practice. Last but not least I will look for solutions to the adverse economic impact of population ageing. In my study at first I will explain the concept of an ageing population and analyze past demographic trends in the Czech Republic. The entire chapter I will attend to migration and migration policy. Then I will focus on demographic forecast and especially replacement migration. At the end of my work I will analyze the economic impacts of an ageing population and the possibilities for their solution.

The aim of this diploma thesis is to create two composite indicators which will provide an informative value about the standard of living of seniors in selected countries of OECD. Using these indicators it will be possible to make a comparison of standards of living on the international level. First of the indicators is Consolidated replacement rate (CRR) which measures income conditions of seniors, which from the economical point of view is considered as the source of standard of living. The construction of CRR is built on theoretical basics from an OECD publication - Pension at Glance 2013. The main component of CRR indicator is a replacement rate which compares income of seniors before and after the retirement. CRR is also composed of two other indicators influencing disposable pension of seniors - imputed rents and services provided by the public sector. The highest values of CRR were reached by Netherlands, Hungary, Iceland and Denmark. On the opposite side the lowest values had countries like Great Britain, Germany and Poland. The reason of this low score for Great Britain and Germany was unavailability of data of private incomes of seniors and therefore it could not be included into CRR. The second constructed indicator is Standard of living of seniors (SLS) which provides a more complex view on the standard of living of seniors using variations of different indicators selected by the author. It includes for example the income situation, risk of poverty and social exclusion or happiness of seniors. Countries with the best values of SLS were Denmark, Netherlands, Iceland and Luxembourg. By far the lowest score was gained by Portugal followed by Estonia, Poland and Greece. In comparison with other countries the Czech Republic was below average among the observed OECD countries with the fifth lowest score of CRR and slightly below average in SLS.

Customers expect electricity to be not only available but also affordable whenever they need it. Due to the stochastic nature of power system component failure, the management of power interruption is challenging. Although the reliability of supply can usually be increased by employing redundant equipment; this means that affordability is compromised. At present, many power utilities have a considerable amount of aged equipment in their networks. Although they have already started replacement planning, the price control schemes imposed by regulatory authorities constrain their capital expenditure budget. This thesis has studied the influence of the end-of-life failure of power transformers on transmission system reliability in order to make decisions on their replacement. Power transformers are selected for the analysis because they are technically complex, expensive, and main feed points of electricity for end users. In addition, surveys on ageing asset show that 50% of transformer populations, in many utilities, have been classified as old since the year 2008. The focus of these reliability analyses is to identify the most critical transformers and to establish a reliability based replacement framework. Modelling of end-of-life failure was reviewed, and the state-of-the-art method of its incorporation into system reliability was adopted. A reliability assessment tool within DIgSILENT PowerFactory package was developed in order to perform reliability studies. This thesis has four original contributions surrounding transmission system reliability analysis. The first contribution is the development of a cost-effective framework that concerns the application of reliability studies on asset replacement decision making. The developed framework has employed reliability importance measures, the Pareto analysis and economic comparison based on reliability incentive/penalty schemes. All the three elements of the framework are original applications to system reliability area. The second contribution is the integration of unconventional end-of-life failure models into system reliability. The unconventional model used in this study is Arrhenius-Weibull distribution, which characterises end-of-life failure under different loading conditions. This study has evaluated the added value provided by including loading levels in failure models and how this enhances the understanding of the effect of operational factors on system reliability. The third contribution is the investigation of dependent failure of power transformers caused by thermal stress. This investigation has led to the development of two probabilistic indicators to rank power transformer based on their criticality to multiple failure events. These new indicators have related the transformer reliability to its age and loading levels. In the fourth contribution, comprehensive studies of the effect of uncertainty associated with failure model parameters were performed. The first study has established bases for a system related approach for refining failure models. The approach is based on assessing the sensitivity of the system reliability or the system reliability applications to the uncertainty in failure model parameters. In the second study, two quantification methods were adopted to propagate the uncertainty in failure model parameters to system reliability indices. These are the second order probability and evidence theory. The last uncertainty study has described the use of sampling based sensitivity analysis to identify the most critical transformers and their area of vulnerability. Studies throughout the thesis have been performed on a realistic transmission network and the IEEE Reliability Test System.

This thesis focuses on the development of pension formula and its detailed analysis for the 1996 -- 2012 time period. The theoretical part describes pension system in general and places the Czech pension system within the systems of other OECD members. In the practical part I analyze specific criteria of the formula and I estimate the impact of these criteria on the size of pension, and which of the criteria add to the solidariy of the pension system.

Orientador: Adriana Orcesi Pedro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-27T01:25:39Z (GMT). No. of bitstreams: 1 Carmignani_LucioOmar_D.pdf: 1313710 bytes, checksum: e5a2ce3ebfaf92d14e105ee597ca752a (MD5) Previous issue date: 2015 / Resumo: Objetivos: Comparar os efeitos da ingestão diária de um suplemento alimentar à base de isoflavona de soja, terapia hormonal (TH) de baixa dosagem e placebo sobre a qualidade de vida (QV) em mulheres sintomáticas na pós-menopausa e avaliar a correlação entre a melhora dos sintomas da menopausa e a QV de acordo com o tipo de tratamento e comparar os efeitos de cada uma das intervenções sobre o sistema urogenital da mulher na pós-menopausa. Métodos: Ensaio clínico randomizado, duplo-cego e controlado envolvendo 60 mulheres na pós-menopausa, com idade entre 40 e 60 anos. Foram selecionadas e randomizadas em três grupos: um grupo recebeu um suplemento alimentar à base de soja (isoflavona 90mg/dia), outro grupo recebeu terapia hormonal de baixa dose (estradiol 1mg e acetato de noretisterona 0,5mg) e um grupo-controle que recebeu placebo, por um período de 16 semanas. O Menopause Rating Scale (MRS) foi utilizado para avaliar as mudanças nos sintomas climatéricos. A QV foi avaliada através da Versão Abreviada do Instrumento de Avaliação de Qualidade de Vida da Organização Mundial de Saúde (WHOQOL-BREF). Os instrumentos foram aplicados no início e após 16 semanas de tratamento. As queixas urinárias, vaginais e sexuais foram avaliadas através da subescala urogenital do MRS. A avaliação dos efeitos terapêuticos no sistema urogenital foi realizada através da medida do pH vaginal e calculo do valor de maturação vaginal. A espessura endometrial foi mensurada através da ultrassonografia transvaginal. A análise estatística foi realizada usando-se o teste do qui-quadrado, teste exato de Fisher, teste t de Student pareado, teste de Kruskal-Wallis, teste não paramétrico de Kruskal-Wallis e análise de variância (ANOVA). Para a análise intergrupo dos escores do MRS e da QV foi utilizado ANOVA, teste de Kruskal-Wallis e Kruskal-Wallis seguido de Mann-Whitney. Para a análise de correlação usou-se o coeficiente de correlação de Spearman. Para a comparação intergrupo das subescalas urogenitais do MRS utilizou-se o teste não paramétrico de Kruskal-Wallis seguido de Mann-Whitney. Resultados: A média de idade das participantes foi de 52,4 (±3,9) anos com tempo médio desde a menopausa de 4,1 (±3,1) anos. Os escores de QV aumentaram significativamente no domínio físico da QV nas usuárias da TH e em menor escala no grupo da soja (233,1% x 39,7%; p=0,02). Apenas no grupo que utilizou TH houve correlação significativa entre a melhora dos sintomas climatéricos e a melhora nos domínios físico (p=0,01) e psicológico (p=0,01) da QV e na questão da saúde geral (p<0,01). A avaliação do sistema urogenital mostrou que houve melhora da secura vaginal nos grupos da soja e da TH (p=0,04). As queixas sexuais e urinárias não se alteraram ao longo do tratamento. Apenas no grupo que usou TH houve um aumento significativo no índice de maturação vaginal (p<0,01) e uma diminuição no pH vaginal (p<0,01). Não houve mudança na espessura endometrial e os efeitos colaterais foram semelhantes nos três grupos estudados. Conclusões: O uso da terapia hormonal mostrou-se eficaz na melhora nos escores do domínio físico da qualidade de vida, isto também foi observado com o uso da isoflavona em uma escala muito menor, mas superior ao uso do placebo, porém apenas o grupo que utilizou a terapia hormonal apresentou uma correlação significativa entre a melhora dos sintomas climatéricos e a melhora na qualidade de vida. O uso de suplemento alimentar à base de soja contendo isoflavonas mostrou eficácia comparável à da terapia hormonal na melhora do ressecamento vaginal, sem exercer ação estrogênica no trato urogenital, em mulheres na pós-menopausa, e superior ao placebo / Abstract: Objectives: To compare the effects of a soy-based dietary supplement, low-dose hormone therapy (HT) and placebo on climacteric symptoms and on quality of life (QOL) of symptomatic postmenopausal women, and to evaluate the correlation between the improvement in menopausal symptoms and QOL according to treatment type, and also assess the effects of each intervention on the urogenital system in postmenopausal women. Methods: This was a double-blind, randomized and placebo-controlled clinical trial. Sixty healthy postmenopausal women, aged 40-60, were recruited and randomly assigned to three groups: a soy dietary supplement group (isoflavone 90mg/day), a low-dose HT group (estradiol 1mg plus noretisterone acetate 0.5mg) and a placebo group. Menopausal symptoms changes were evaluated through Menopause Rating Scale (MRS). QOL was measured by the abbreviated version of the World Health Organization¿s Quality of Life instrument (WHOQOL-BREF). These instruments were applied at baseline and after 16 weeks of treatment. Urinary, vaginal and sexual complaints were evaluated by using the urogenital subscale of the MRS. Evaluation of therapeutic effects on urogenital system was performed by vaginal pH measurement and maturation value calculation. Transvaginal sonography was performed to evaluate endometrial thickness. Statistical analysis were performed using the chi-square test, Fisher's exact test, paired Student¿s t-test, Kruskal-Wallis test, Kruskal-Wallis nonparametric test, and analysis of variance (ANOVA). For MRS and QOL scores intergroup analysis were used ANOVA, Kruskal-Wallis test, and Kruskal-Wallis followed Mann-Whitney test. Correlation analysis was performed using the Correlation Spearman Coefficient. For Intergroup comparisons related to MRS urogenital subscale, the Kruskal-Wallis nonparametric test was used, followed by the Mann-Whitney test. Results: The mean age of the patients was 52.4 (±3.9) years, with 4.1 (±3.1) years mean time since menopause. QOL scores increased significantly in the physical health domain of QOL in the users of HT and in a much lesser extent in the soy group (233,1% x 39,7%; p=0,02). It was observed that only in the HT group there was a statistically significant correlation between the improvement of symptoms of total MRS and improvement in the QOL physical (p=0.01) and psychological (p=0.01) domains and also on general health assessment (p<0.01). Urogenital system evaluation showed a significantly improvement in vaginal dryness in the soy group and HT group (p=0.04). Urinary and sexual symptoms did not change with treatment in the three groups. After 16 weeks of treatment, there was a significant increase in maturation value only in the HT group (p<0.01). Vaginal pH decreased only in this group (p<0.01). There were no statistically significant differences in endometrial thickness between the three groups and the adverse effects evaluated were similar. Conclusions: Hormone therapy was effective in improving the physical health domain of QOL, it was also observed with the use of isoflavones on a much lesser extent, but superior to placebo. However, only the HT group showed a significant correlation between the improvement of climacteric symptoms and the improvement in QOL. The use of soy-based dietary supplement containing isoflavones showed an efficacy similar to that of HT in improving vaginal dryness, and greater than placebo, without exerting estrogen action on urogenital tract in postmenopausal women / Doutorado / Fisiopatologia Ginecológica / Doutor em Ciências da Saúde

Le nombre de prothèses totales de hanche (PTH) posées en France est en forte augmentation en France depuis plusieurs années : +10% en 4 ans, avec plus de 100 000 poses en 2013. Cette augmentation est liée à la fois au vieillissement de la population et à l’élargissement de la patientèle implantée : les PTH sont posées chez des patients plus jeunes et actifs, et à l’autre extrême, chez des patients de plus en plus âgés, présentant davantage de comorbidités Le volume de pose de PTH, leurs caractéristiques, leur contexte de pose et la population implantée n’ont pas encore été décrits de manière exhaustive en France, contrairement aux pays disposant de registre d’arthroplastie (les pays nordiques et anglo-saxons). L'objectif de ma thèse était d'étudier quels sont les facteurs pronostics de la survie des PTH. La recherche portait sur les caractéristiques des implants, les caractéristiques des patients et les caractéristiques des séjours d’implantation. Les bases de données utilisées sont celles du SNIIRAM de 2006 à 2016, comprenant les remboursements de soins en ville (de 2006 à 2016) et à l’hôpital (de 2006 à 2015) des assurés affiliés à un régime obligatoire de l’assurance maladie. Environ 100 000 PTH sont implantées chaque année en France. La cohorte globale des patients porteurs de prothèse de hanche, implantée de 2006 à 2014 comprend environ un million de patients. Les études de cette thèse ont été conduites sur des cohortes de 100 000 à 300 000 patients, inclus de 2009 à 2012 et suivis jusqu’en 2013 à 2014.Ces études indiquent que les caractéristiques prothétiques, couple de frottement, mode d’ancrage, choix d’un col modulaire, sont associés à la survie de la PTH à court et moyen terme. Il en est de même pour les caractéristiques des patients, âge, sexe, diabète, ainsi que l’exposition à certains médicaments, dont les benzodiazépines. Les caractéristiques du centre dans lequel est implantée la prothèse, en particulier le volume d’activité du chirurgien implanteur, sont associées à la survie prothétique.L’utilisation des bases de données du PMSI permet une surveillance active des PTH et ont permis d’identifier à court terme certains facteurs de risque d’échec de la prothèse. Environ 100 000 patients sont implantés par PTH en France chaque année. La révision prothétique est une intervention à risques, avec des taux de complications per et post-opératoires plus élevés que pour la primo-implantation. Mieux comprendre les facteurs liés à l’échec de la PTH et agir en faveur de la survie prothétique sont donc des enjeux de santé publique. Nos travaux ont pour finalité de faire évoluer les pratiques et encourager les choix techniques les plus favorables pour la survie prothétique, de manière à contribuer à l’amélioration de la santé des patients. / More and more Total Hip Replacement (THR) are performed in France (PTH) these last decades ; a 10% increase in 4 years has been observed, with 100 000 implantations on 2013.This increase can is related to the ageing of the population as well as the expansion of the implanted population: on one side younger and more active patients are now implanted, and on the other side, older patients (more than 80), often with other comorbidities, are now implanted.Le number of implanted THR, their characteristics, the context of implantation et the characteristics of the implanted population in France have never been comprehensively described so far. Some data are available from international registries (from Nordic, British, North American coutries and Australia), but not in France. The aim of my PhD was to study which factors were associated with the THR survivorship. My research covered the characteristics of the implants, of the patients and of the implanting centers.The data we used were from the French National Health Insurance Information System, SNIIRAM (Système National d'Information Inter-Régimes de l'Assurance Maladie) from 2006 to 2016. About 100 000 THR are implanted annually in France; the total cohort of THR implanted patients between 2006 and 2014 comprises about a million subjects. The cohorts studied in my work comprises between 100 000 and 300 000 patients, included between 2009 and 2012 and followed until 2013 to 2014.These cohorts studies showed that the implants characteristics, bearing surface, cementation, choice of a modular neck are associated with the prosthetic survivorship at short and midterm follow-up. We found the same with the patients characteristics, age, sex, diabetes mellitus as well as exposure to drugs such as benzodiazepines. The characteristics if the implanting center are also associated to the prosthetic survivorship, more specifically the volume of activity of the surgeon who performed the hip arthroplasty.The PMSI data are a valuable tool to perform an active surveillance of THR survivorship and using them allowed us to identify several risk factors of revision at short to midterm follow-up. About 100 000 patients receive a THR annually in France and THR revision is a surgical operation far more complicated than primary implantation, with higher complications rate during and post-operation. Being able to identifiy the factors associated with THR revision and being able to take the measures improving the THR survivorship are indeed a major Public health challenges. Our work' purpose is to assess the current practices and to provide evidences to promote technical choices propitious to THR survivorship, to contribute to health quality improvement.