O anticorpo anti-proteína P ribossomal é um dos marcadores sorológicos do lúpus eritematoso sistêmico, previamente associado a glomerulonefrite lúpica classe V (ISN-RPS). Neste trabalho foi avaliado o prognóstico renal em pacientes que possuem positividade para este anticorpo. Sessenta pacientes foram avaliados para parâmetros de sobrevida renal. Onze pacientes (18%) apresentaram positividade sorológica exclusiva para anticorpo anti-P ribossomal e vinte e oito pacientes (47%) para anti-dsDNA. Ao final do período de seguimento, foi observado que os pacientes anti-P positivos apresentaram uma maior sobrevida renal (11,0 ± 4,5 vs. 9,2 ± 4,5 anos, p=0,03) quando comparados aqueles anti-P negativos, assim como menor frequência de necessidade de terapia substitutiva renal (0 vs. 35% p = 0,025). Pacientes anti-P positivos apresentaram também maior frequência de classe V (91% vs. 31%, p < 0.001) e menor incidência de alterações proliferativas (45% vs. 82%, p = 0,021) na avaliação da biópsia renal quando comparados aos pacientes sem a positividade para este anticorpo. Os dados reforçam a hipótese de que o anticorpo anti-P é um marcador útil de um melhor prognóstico renal em pacientes portadores de lúpus eritematoso sistêmico / Antibodies to ribossomal P proteins are one of the serologic markers of systemic lupus erythematosus, previously described as associated to class V lupus glomerulonephritis (ISN-RPS). Our study assessed renal prognosis in patients with anti-P antibodies. Sixty consecutive SLE patients with biopsyproven nephritis (2004 ISN/RPS) were evaluated for renal survival parameters. Eleven patients (18%) had exclusive anti-P positivity and 28 (47%) patients anti-dsDNA. The post-biopsy follow-up analysis demonstrated that anti-P positive patients disclosed better renal survival (11.0 ± 4.5 vs. 9.2 ± 4.5 years, p = 0.03) as well as lower frequency of patients requiring dialysis (0 vs. 35% p = 0.025). The frequency of class V nephritis was higher in anti-P positive patients (91% vs. 31%, p < 0.001) and the occurrence of proliferative lesions at biopsy was lower in these patients (45% vs. 82%, p=0.021). Our data supports the notion that anti-P antibody is a valuable marker to predict a better long-term renal outcome in lupus patients

在此篇論文中，我們提出一個慢性Ｂ型肝炎病毒感染病程之數學模型。因為在病症間的轉移機率(Transition probability)是隨著患者的年齡變動，所以在過去的文獻中，已經有學者提出，在疾病轉移機率模型中，應加入國民生命表(Life table)，藉此讓機率模型更符合Ｂ型肝炎病患的生命歷程。但是過去的文獻中，學者並沒有利用加入國民生命表之後疾病模型做進一步的病程分析。在這篇論文當中，我們假設原始的疾病轉移模型是符合馬可夫鏈的性質，並且提出一種加入國民生命表的方法，賦予疾病有年齡相關特性之模型。根據文獻數據和類馬可夫機率性質，我們使用著名的Chapman-Kolmogorov公式計算Ｂ型肝炎的自然病程機率，並畫出病人的生存機率曲線(Survival curve)。文章最後將會藉由兩個例子來介紹此篇論文提出的模型。實驗數據結果證實，此模型不僅提供了一個更精確的方法去分析在病症與死亡間的轉移機率、平均餘命(Life expectancy)、以及在不同年齡的存活機率(Survival probability)，並且可以更進一步的分析且瞭解病情狀態之間的轉移狀況。 / In this thesis, we propose a new mathematical model extending the natural history of hepatitis B virus (HBV) prognosis progression on chronic HBV infection. Since the actual transition probabilities between symptoms are dependent of ages, it has been proposed that the life table should be accommodated to the HBV prognosis progression model so that it can more properly explain the disease progression of the HBV patients. But in the literature, no further disease analysis and applications of it with the life table are discussed. In this thesis, we assume that the original disease progression is described by a Markov model, and propose a new method to combine the HBV progression with the life table so that the proposed model integrates data from the life table and allows the accommodation of age-dependent properties of the target disease. With clinical data based on annual incidence rates, the entire model is Semi-Markov based in nature. Computation methods similar to the celebrated Chapman-Kolmogorov equation can be applied to study the associated probability of each likely trajectory with desired initial ages and health states under the scenarios of natural history and various treatment policies. This method provides a more accurate way to analyze the transitions between symptoms, such as the mean life expectancy or the survival probabilities at different ages. We will give examples to demonstrate the proposed method in this thesis. Numerical results show the proposed model not only provides a more accurate method to analyze the mean life expectancy, the survival probabilities at different ages, and the transition probabilities from symptoms to death but also helps us to understand the transitions between symptoms.

可轉換公司債為複合式證券，除了具有債券性質外，並給予持有者於債券流通期間內行使轉換為股票之權利。以存活分析方法探討可轉債之研究尚屬少見，本論文乃以台灣上市櫃公司發行之5年期可轉債為研究資料，先整理出與公司經營有關的變數，再分別以Cox模式與再發事件之兩種邊際模型(marginal model)：A-G (Anderson-Gill) 模式、PWP-TT (Prentice-Williams-Petersen)模式為研究分析方法，探討可轉債之流通時間及大量交易時間的問題。本論文並將可轉債分類為債券類型、混合類型和權益類型，且由於不同類型可轉債之流通時間有所差異，因此以其為分層條件加入模式中進行分析。研究結果發現，資產總額、總負債率、TCRI評等及董監持股率等變數，具有顯著解釋可轉債流通時間的能力，可見公司財務負債狀況與穩定性與流通期間有關；而最高差價(當月最高股價與轉換價之相對差價)、長期負債率、總負債率及股價報酬率等變數，則可顯著解釋大量交易的發生時間，表示公司財務負債狀況與股價利潤差與大量交易發生之快慢有關，其中資產總額、最高差價、TCRI評等及股價報酬率之係數均顯著為正，長期負債率、總負債率及董監持股率之係數則顯著為負。由於平均表現之存活曲線與經驗存活曲線相當接近，以Kolmogorov-Smirnov檢定多無顯著差異，顯示這些模式有不錯的配適能力；至於對個別公司估計出之存活曲線，則或有與經驗存活曲線相差較多的現象，顯示所建立的模式可對個別公司提供可轉債即將結束流通或發生大量交易之預警。 / Convertible bonds are hybrid securities that possess the properties of bonds and the right to convert bonds into shocks. Few articles employed survival analysis to analyze the characteristics of convertible bonds. To investigate the effects of the issuer’s financial information to the duration of circulation and the timing of the massive trading about convertible bonds, Taiwan’s 5-year convertible bonds were collected, and three methods of survival analysis were employed：Cox model、A-G (Anderson-Gill) model and PWP-TT(Prentice-Williams-Petersen) model. We classified convertible bonds as debt-like, equity-like, and hedge-like, and then make the classification as a stratification condition later. In summary, total Assets, total debt ratio, TCRI, and the proportion of holding share in supervisors and directors are significant variables on circulation period of convertible bonds. Apparently, the extent of debt and financial stability of issuers have significant effects on circulation period; the difference between stock price and conversion price, long-term debt ratio, total debt ratio and stock return rate contribute significantly on the timing of massive trading of convertible bonds. While the extent of debt and the return of stock hasten the hazard of the timing of massive trading. Furthermore, there are no significant differences between the survival curves evaluated at the average performance levels and the corresponding empirical survival curves, according to the results of Kolmogorov-Smirnov test. However, the differences between individual survival probabilities and overall empirical survival probabilities might be large, which indicates that the models incorporate companies’ performance overtime may provide a warning message for the termination of circulation or the timing of massive trading for a particular convertible bond.

BACKGROUND: Human papilloma virus (HPV) in patients with esophageal carcinoma has previously been studied with an average detection rate of 15%, but the role of HPV in relation to survival is less clear. In cervical cancer, lung cancer and tonsil cancer HPV viral load is a predictive factor for survival and outcome of treatment. The primary aim was to study the spectrum of high-risk HPV types in esophageal tumors. Secondary, as a pilot study we investigated the association between HPV status and the survival rates. METHODS: We compared both the presence and the viral load of high-risk HPV types 16, 18, 31, 33, 39, 45, 52, 58, and 67 in relation to clinical data from patients with esophageal carcinoma. Survival data and tumor samples were retrieved from 100 patients receiving treatment at the Department of Oncology, Uppsala Hospital, Uppsala, Sweden. The tumor samples were investigated for HPV viral load using real-time PCR. RESULTS: HPV 16 was detected in 16% of the patients; no other HPV type was detected. HPV 16 infection had no significant effect on survival (p = 0.72). Also, HPV 16 did not improve survival after treatment (radiotherapy or chemotherapy). CONCLUSION: Only HPV 16 was detected among the patients. HPV 16 in esophageal carcinoma patients did not influence survival or improve therapy response. However, given the size of the study there is a need to examine a larger cohort in order to understand in more detail the effect of high risk HPV types in esophageal carcinoma. / <p>De två första författarna delar förstaförfattarskapet.</p>

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).

Aquesta tesi avalua l'existència de diferencies per gènere en la relació entre discapacitat i mortalitat, i aspectes metodològics en l'anàlisi de supervivènciad'estudis de gent gran. Es van utilitzar les dades provinents d'una cohort de 1.315 subjectes amb edats superiors o iguals a 65 anys que van ser seguits durant un periode de 8 anys. La discapacitat es va mesurar mitjançant la capacitat que declarava l'individu per dur a terme activitats de la vida diària bàsiques. La discapacitat va evolucionar al llarg del temps empitjorant amb l'edat, però una proporció no menyspreable va ser capaç de recuperar-se. Es van observar diferències per gènere en l'evolució de la discapacitat: les dones tenien més dificultats en recuperar la seva capacitat funcional un cop esdevenien discapacitades. La força de l'associació entre la discapacitat i la mortalitat disminuia a edats avançades. Es van trobar diferencies per sexe: les dones depenents mostraven un risc de morir més alt que el homes depenents. Polítiques de salut dirigides a dones discapacitades haurien de ser implementades degut a la proporció més elevada de dones discapacitades, la probabilitat menor que tenen de recuperar la capacitat funcional, i el risc de morir més elevat que presenten comparat amb homes dicapacitats. / This thesis evaluates the existence of gender differences in the relationship between disability and mortality, as well as methodological aspects of the survival analysis for elderly studies. Data from a cohort of 1,315 subjects aged 65 years and older followed-up 8 years was used. Disability was assessed by self-reported difficulty to perform basic activities of daily living. Disability evolved over time worsening with age, but a non-negligible proportion was able to recover. There were gender differences in the evolution of disability: women were less able to regain functional capacity once they become disabled. The strength of the association between disability and mortality decreased in the older ages. But differences by gender were found: dependent elderly women showed a higher risk of dying compared to dependent men. Health policies focusing on disabled women should be implemented, due to the higher proportion of disabled women, the lower probability of regaining functional capacity, and their higher risk of dying compared to disabled men.

Fire is the primary natural disturbance vital to the ecological integrity of Quetico Provincial Park, Ontario, Canada. A new provincial park planning process (i.e., Class Environmental Assessment) has required the review of Quetico’s Fire Management Plan. To support this review, large and severe (stand-replacing) Quetico fires were studied using 1966 Ontario Ministry of Natural Resources (OMNR) forest resource inventory (FRI) mapping. A Geographic Information Systems (GIS) database of the FRI was created and updated with the OMNR digital fire atlas. This database was used as a time-since-fire and fire interval dataset to estimate fire frequency. It also served to archive the 1966 FRI for the largest protected area in the transition between the Boreal and Great Lakes-St. Lawrence forest regions. Non-parametric (Kaplan-Meier) survival analysis was used to estimate survival functions and mean fire intervals (i.e., the expected time between two consecutive stand-replacing fires for any location within the Park). Previous studies that have used Kaplan-Meier survival analysis methods have based fire frequency estimates solely on time-since-fire data. However, time-since-fire data cannot be equated with fire interval data when using non-parametric methods. At least one fire interval is required to obtain reliable results. The mean fire interval for the entire 475,782 ha Park between the years 1668 and 2007 was 230 years. Performing the analysis on various geographic and temporal partitions revealed fire frequency spatial and temporal variability. A constant (independent of time-since-fire) probability of burning was not observed for Quetico which is contrary to accepted conjecture for northwestern Ontario boreal/mixed-wood forests. A current fire cycle was also estimated for the Park (342 years) using the digital fire atlas. The results suggested that use of historical static fire frequency estimates as fire management prescriptions may not be justified given considerable fire frequency temporal variability. The observed fire frequency spatial variability suggests that studies should be undertaken at coarser scales than is the norm to characterise the regions fire regime in support of landscape level fire management planning.

Fire is the primary natural disturbance vital to the ecological integrity of Quetico Provincial Park, Ontario, Canada. A new provincial park planning process (i.e., Class Environmental Assessment) has required the review of Quetico’s Fire Management Plan. To support this review, large and severe (stand-replacing) Quetico fires were studied using 1966 Ontario Ministry of Natural Resources (OMNR) forest resource inventory (FRI) mapping. A Geographic Information Systems (GIS) database of the FRI was created and updated with the OMNR digital fire atlas. This database was used as a time-since-fire and fire interval dataset to estimate fire frequency. It also served to archive the 1966 FRI for the largest protected area in the transition between the Boreal and Great Lakes-St. Lawrence forest regions. Non-parametric (Kaplan-Meier) survival analysis was used to estimate survival functions and mean fire intervals (i.e., the expected time between two consecutive stand-replacing fires for any location within the Park). Previous studies that have used Kaplan-Meier survival analysis methods have based fire frequency estimates solely on time-since-fire data. However, time-since-fire data cannot be equated with fire interval data when using non-parametric methods. At least one fire interval is required to obtain reliable results. The mean fire interval for the entire 475,782 ha Park between the years 1668 and 2007 was 230 years. Performing the analysis on various geographic and temporal partitions revealed fire frequency spatial and temporal variability. A constant (independent of time-since-fire) probability of burning was not observed for Quetico which is contrary to accepted conjecture for northwestern Ontario boreal/mixed-wood forests. A current fire cycle was also estimated for the Park (342 years) using the digital fire atlas. The results suggested that use of historical static fire frequency estimates as fire management prescriptions may not be justified given considerable fire frequency temporal variability. The observed fire frequency spatial variability suggests that studies should be undertaken at coarser scales than is the norm to characterise the regions fire regime in support of landscape level fire management planning.

本研究針對房屋本身具有高度異質性、昂貴性、耐久性、低重複購買頻率、消費與投資雙重性等特性，使得一般行銷研究結果，套用在解釋購屋搜尋行為可能產生問題。但以往房屋市場之搜尋行為研究，多著重價格之搜尋，且忽略其他管道使用情形，難以全面窺視購屋者之搜尋行為，故本研究依據前述房屋主要的幾個特性，藉由回顧搜尋行為相關理論與文獻提出研究假說，透過存活分析法與多項邏輯特模型進行實證，重新審視購屋者之搜尋行為。 首先，考量房屋不同於一般消費性商品之特性，可能使得一般行銷研究結果，套用在解釋購屋搜尋行為時產生問題，故以存活分析探討這些特性對搜尋期間可能造成的影響。研究結果發現購屋目的顯著影響搜尋期間，且購屋者在搜尋時會同時重視產品與價格，其重視程度增加將拉長搜尋期間，而時間壓力對搜尋期間影響則不顯著。最後，透過仲介購屋之購屋者，因為可供考慮物件增多，且服務費用多寡與取得物件數量無關，因此，其搜尋期間較自行搜尋者增加。研究結果在實務上的意涵為，當景氣處於較低迷時，業者應多提供購屋者關於產品之外部資訊，特別是與家戶切身相關之房屋資訊，並極力避免價格戰，而仲介業者也應重新檢討目前的服務方式，以期達成協助購屋者迅速成交之企業訴求。 而房屋的消費與投資雙重性與經驗財之特性，使得個人對房價的認知與預期的差異，影響其搜尋期間，而產生有限理性之決策。本研究以存活分析探討個人目前房價認知與未來房價預期差異對搜尋期間的影響。結果顯示定錨效應確實影響購屋搜尋行為，在納入個人目前房價認知後，自住者對房價看法看漲者參考點較高，搜尋期間縮短，反之，看跌者搜尋期間較長。也就是對目前房價看法越樂觀，但對一年後房價看法悲觀者，其參考點向下修正幅度越高。研究結果主要貢獻在釐清購屋搜尋行為為有限理性決策，房價看法應由目前房價認知與未來房價預期共同構成，且未來房價預期有加強定錨效應的情況。 除前述特性以外，房屋尚有低重複購買頻率的特性，雖然相關研究證實經驗確實會影響搜尋期間，卻忽略租屋經驗可能造成的影響，特別是租屋搜尋與購屋搜尋有部分相似，但以往卻少有研究討論，更遑論深入分析兩種經驗個別對購屋搜尋行為的影響。本研究透過存活分析法，去探討購屋經驗、租屋經驗，對預售屋、成屋購屋搜尋行為的影響。研究結果顯示，就購買成屋部分，相對於無任何經驗之購屋搜尋者，租屋經驗與搜尋期間為正向關係，購屋經驗與搜尋期間為負向關係。而仲介服務則有助於提升中度經驗者之經驗水準，縮短其搜尋期間。就購買預售屋部分，僅購屋經驗有顯著負向影響，但租屋經驗似乎難以延伸至預售屋之購買。研究結果主要貢獻在於，釐清先前租屋經驗確實可延伸至本次的購屋搜尋，而購屋經驗對購屋搜尋期間之影響為負向，租屋經驗對搜尋期間影響為正向，且兩者對預售屋、成屋之購屋搜尋期間影響不同，故在進行分析與研究結論的引用時，應予以分別討論。 除探討搜尋期間外，本研究更針對含個人來源與商業來源不同管道對搜尋期間之影響進行討論。研究結果顯示，購屋者資訊搜尋管道之選擇，以商業來源與混合來源居多，且常使用含個人來源搜尋之購屋者，搜尋期間較有使用商業來源者短。此結果表示對購屋者而言，搜尋管道並非互斥，購屋者會努力使用不同管道去搜尋資訊，以降低決策之不確定性，且隱含購屋者對商業來源有一定程度的不信任。因此，建議業者除維持現有行銷管道，應加強口碑行銷，以提升溝通效率。 / House is a durable good with heterogeneity, expensiveness, and low liquidity, and also an investment and consumption product. Those characteristics made housing search behavior not to be applied appropriately from the general marketing research results. This dissertation employs search theory, behavior theory, survival analysis, and multinomial logit model to study four relative essays. The first essay tries to explain the difference between houses and consumer goods. Our research tested three hypotheses by questionnaires which investigated the person who is in charge family livelihood and bought house during 1998 and 2002 in Tai-chung. The three hypotheses have been confirmed. First, because the house is a good important to all family members, the search duration of the houses for self-living is longer than those for investment. Second, not only the price differences affect the search duration but also the product differences do; however, the influences of time pressure and purchase experience on search duration are not significant. Last but not least, because house searchers have more house selling information through brokers and no additional cost from visiting one more house, they prefer to extend their search duration compared to those who search by himself. The meaning of our research in practice is that the house seller should provide more product information to house buyer and give every effort to avoid price war. The second essay is to discuss how house searchers measure search costs and benefits with utility or price if they are rational decision-makers. We develop a hypothesis and a search model of indefinite and sampling without recall which integrates the studies on worker search, prospect theory, and search behavior. The data comes from “Taiwan Housing Demand Survey” and includes home-buyers and home-searchers from 2003Q1 to 2003Q4. The result shows that the buyers are bounded rational, and the stopping ratio has time dependency. The buyers tend to search for minimum price during the economic fluctuation. When the consumption buyers have a higher housing price perception, they also have a higher reference points, it makes them shorten their search duration. And their price expectation would enhance the anchoring effect. Searching more can bring the buyers benefits mainly from utility increase but not price discount. Therefore, it seems reasonable to subsume individual price perception and expectation when analyzing home-buyers’ search behaviors. The third essay focuses on the effects of homebuyers’ buying and renting experience on their search behaviors. The data also comes from “Taiwan Housing Demand Survey” and includes home-buyers and home-searchers from 2003Q1 to 2004Q1. The results show that our two hypotheses are supported. The effects of homebuyers’ prior house buying experience on search duration are different from their prior house renting experience. While buying a pre-sale or existing house, the buyers with renting experience have longer duration than the buyer with buying or non-experience. In addition, only buying experiences of homebuyers have positive relation with the search duration of pre-sale houses. The final essay has two goals. One is to explore how homebuyers choose information sources. The other is to examine the relationship between information sources and search duration. The data comes from “Taiwan Housing Demand Survey” and includes the questionnaires from sampled homebuyers of 2005Q3. We also use survival model to test our hypotheses. The results show that homebuyers incline to use the commercial sources and mix sources. Even the limit of personal source, it can reduce the buyers’ search duration. Therefore, in order to improve transaction efficiency, the firms should make use of their existing marketing channels and try to build good word-of-mouth as well.

L’explosion récente du nombre de centenaires dans les pays à faible mortalité n’est pas étrangère à la multiplication des études portant sur la longévité, et plus spécifiquement sur ses déterminants et ses répercussions. Alors que certains tentent de découvrir les gènes pouvant être responsables de la longévité extrême, d’autres s’interrogent sur l’impact social, économique et politique du vieillissement de la population et de l’augmentation de l’espérance de vie ou encore, sur l’existence d’une limite biologique à la vie humaine. Dans le cadre de cette thèse, nous analysons la situation démographique des centenaires québécois depuis le début du 20e siècle à partir de données agrégées (données de recensement, statistiques de l’état civil, estimations de population). Dans un deuxième temps, nous évaluons la qualité des données québécoises aux grands âges à partir d’une liste nominative des décès de centenaires des générations 1870-1894. Nous nous intéressons entre autres aux trajectoires de mortalité au-delà de cent ans. Finalement, nous analysons la survie des frères, sœurs et parents d’un échantillon de semi-supercentenaires (105 ans et plus) nés entre 1890 et 1900 afin de se prononcer sur la composante familiale de la longévité. Cette thèse se compose de trois articles. Dans le cadre du premier, nous traitons de l’évolution du nombre de centenaires au Québec depuis les années 1920. Sur la base d’indicateurs démographiques tels le ratio de centenaires, les probabilités de survie et l’âge maximal moyen au décès, nous mettons en lumière les progrès remarquables qui ont été réalisés en matière de survie aux grands âges. Nous procédons également à la décomposition des facteurs responsables de l’augmentation du nombre de centenaires au Québec. Ainsi, au sein des facteurs identifiés, l’augmentation de la probabilité de survie de 80 à 100 ans s’inscrit comme principal déterminant de l’accroissement du nombre de centenaires québécois. Le deuxième article traite de la validation des âges au décès des centenaires des générations 1870-1894 d’origine canadienne-française et de confession catholique nés et décédés au Québec. Au terme de ce processus de validation, nous pouvons affirmer que les données québécoises aux grands âges sont d’excellente qualité. Les trajectoires de mortalité des centenaires basées sur les données brutes s’avèrent donc représentatives de la réalité. L’évolution des quotients de mortalité à partir de 100 ans témoigne de la décélération de la mortalité. Autant chez les hommes que chez les femmes, les quotients de mortalité plafonnent aux alentours de 45%. Finalement, dans le cadre du troisième article, nous nous intéressons à la composante familiale de la longévité. Nous comparons la survie des frères, sœurs et parents des semi-supercentenaires décédés entre 1995 et 2004 à celle de leurs cohortes de naissance respectives. Les différences de survie entre les frères, sœurs et parents des semi-supercentenaires sous observation et leur génération « contrôle » s’avèrent statistiquement significatives à un seuil de 0,01%. De plus, les frères, sœurs, pères et mères des semi-supercentenaires ont entre 1,7 (sœurs) et 3 fois (mères) plus de chance d’atteindre 90 ans que les membres de leur cohorte de naissance correspondante. Ainsi, au terme de ces analyses, il ne fait nul doute que la longévité se concentre au sein de certaines familles. / The recent rise in the number of centenarians within low mortality countries has led to multiple studies conducted on longevity, and more specifically on its determinants and repercussions. Some are trying to identify genes that could be responsible for extreme longevity. Others are studying the social, economic and political impact of the rise in life expectancy and population aging, or questioning themselves about the existence of a biological limit to the human life span. In this thesis, we first study the demographic situation of centenarians from Quebec using aggregated data (census data, vital statistics, and population estimations). Then, we evaluate the quality of Quebec data at the oldest ages using the death records of centenarians belonging to the 1870-1894 birth cohorts. We are particularly interested in the mortality trajectories beyond 100 years old. Finally, we analyze the survival of siblings and parents of a semi-supercentenarians (105 years and over) sample in order to assess the familial component of longevity. The thesis is divided into three articles. In the first article, we study the evolution of the centenarian population from the 1920s in Quebec. With demographic indicators such as the centenarian ratio, the survival probabilities and the maximal age at death, we try to demonstrate the remarkable progress realised in old age mortality. We also analyze the determinants of the increase in the number of centenarians in Quebec. Among the factors identified, the improvement in late mortality is the main determinant of the increase of the number of centenarians in Quebec. The second article deals with the validation of the ages at death of French-Canadian centenarians born in Quebec between 1870-1894. The validation results confirm that Quebec data at the highest ages at death are of very good quality. Therefore, the measure of centenarian mortality based on all death records is representative of the true trends. The evolution of age-specific life table death rates beyond 100 years old assesses the mortality deceleration at the highest ages. Among men and women, the death rates reach a plateau at around 45%. Finally, in the third article, we study the familial predisposition for longevity. We compare the survival probabilities of siblings and parents of semi-supercentenarians deceased between 1995 and 2004 to those of their birth cohort-matched counterparts. The survival differences between the siblings and parents of semi-supercentenarians and their respective birth cohorts are statistically significant at a 0,01% level of significance. The siblings and parents have a 1,7 to 3 times greater probability of survival from age 50 to 90 then members of their respective birth cohorts. These findings support the existence of a substantial familial component to longevity.