996 resultados para arbre de régression et de classification


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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

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Résumé : La texture dispose d’un bon potentiel discriminant qui complète celui des paramètres radiométriques dans le processus de classification d’image. L’indice Compact Texture Unit (CTU) multibande, récemment mis au point par Safia et He (2014), permet d’extraire la texture sur plusieurs bandes à la fois, donc de tirer parti d’un surcroît d’informations ignorées jusqu’ici dans les analyses texturales traditionnelles : l’interdépendance entre les bandes. Toutefois, ce nouvel outil n’a pas encore été testé sur des images multisources, usage qui peut se révéler d’un grand intérêt quand on considère par exemple toute la richesse texturale que le radar peut apporter en supplément à l’optique, par combinaison de données. Cette étude permet donc de compléter la validation initiée par Safia (2014) en appliquant le CTU sur un couple d’images optique-radar. L’analyse texturale de ce jeu de données a permis de générer une image en « texture couleur ». Ces bandes texturales créées sont à nouveau combinées avec les bandes initiales de l’optique, avant d’être intégrées dans un processus de classification de l’occupation du sol sous eCognition. Le même procédé de classification (mais sans CTU) est appliqué respectivement sur : la donnée Optique, puis le Radar, et enfin la combinaison Optique-Radar. Par ailleurs le CTU généré sur l’Optique uniquement (monosource) est comparé à celui dérivant du couple Optique-Radar (multisources). L’analyse du pouvoir séparateur de ces différentes bandes à partir d’histogrammes, ainsi que l’outil matrice de confusion, permet de confronter la performance de ces différents cas de figure et paramètres utilisés. Ces éléments de comparaison présentent le CTU, et notamment le CTU multisources, comme le critère le plus discriminant ; sa présence rajoute de la variabilité dans l’image permettant ainsi une segmentation plus nette, une classification à la fois plus détaillée et plus performante. En effet, la précision passe de 0.5 avec l’image Optique à 0.74 pour l’image CTU, alors que la confusion diminue en passant de 0.30 (dans l’Optique) à 0.02 (dans le CTU).

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Efficient automatic protein classification is of central importance in genomic annotation. As an independent way to check the reliability of the classification, we propose a statistical approach to test if two sets of protein domain sequences coming from two families of the Pfam database are significantly different. We model protein sequences as realizations of Variable Length Markov Chains (VLMC) and we use the context trees as a signature of each protein family. Our approach is based on a Kolmogorov-Smirnov-type goodness-of-fit test proposed by Balding et at. [Limit theorems for sequences of random trees (2008), DOI: 10.1007/s11749-008-0092-z]. The test statistic is a supremum over the space of trees of a function of the two samples; its computation grows, in principle, exponentially fast with the maximal number of nodes of the potential trees. We show how to transform this problem into a max-flow over a related graph which can be solved using a Ford-Fulkerson algorithm in polynomial time on that number. We apply the test to 10 randomly chosen protein domain families from the seed of Pfam-A database (high quality, manually curated families). The test shows that the distributions of context trees coming from different families are significantly different. We emphasize that this is a novel mathematical approach to validate the automatic clustering of sequences in any context. We also study the performance of the test via simulations on Galton-Watson related processes.

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Background Schizophrenia has been associated with semantic memory impairment and previous studies report a difficulty in accessing semantic category exemplars (Moelter et al. 2005 Schizophr Res 78:209–217). The anterior temporal cortex (ATC) has been implicated in the representation of semantic knowledge (Rogers et al. 2004 Psychol Rev 111(1):205–235). We conducted a high-field (4T) fMRI study with the Category Judgment and Substitution Task (CJAST), an analogue of the Hayling test. We hypothesised that differential activation of the temporal lobe would be observed in schizophrenia patients versus controls. Methods Eight schizophrenia patients (7M : 1F) and eight matched controls performed the CJAST, involving a randomised series of 55 common nouns (from five semantic categories) across three conditions: semantic categorisation, anomalous categorisation and word reading. High-resolution 3D T1-weighted images and GE EPI with BOLD contrast and sparse temporal sampling were acquired on a 4T Bruker MedSpec system. Image processing and analyses were performed with SPM2. Results Differential activation in the left ATC was found for anomalous categorisation relative to category judgment, in patients versus controls. Conclusions We examined semantic memory deficits in schizophrenia using a novel fMRI task. Since the ATC corresponds to an area involved in accessing abstract semantic representations (Moelter et al. 2005), these results suggest schizophrenia patients utilise the same neural network as healthy controls, however it is compromised in the patients and the different ATC activity might be attributable to weakening of category-to-category associations.

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PURPOSE: Fatty liver disease (FLD) is an increasing prevalent disease that can be reversed if detected early. Ultrasound is the safest and ubiquitous method for identifying FLD. Since expert sonographers are required to accurately interpret the liver ultrasound images, lack of the same will result in interobserver variability. For more objective interpretation, high accuracy, and quick second opinions, computer aided diagnostic (CAD) techniques may be exploited. The purpose of this work is to develop one such CAD technique for accurate classification of normal livers and abnormal livers affected by FLD. METHODS: In this paper, the authors present a CAD technique (called Symtosis) that uses a novel combination of significant features based on the texture, wavelet transform, and higher order spectra of the liver ultrasound images in various supervised learning-based classifiers in order to determine parameters that classify normal and FLD-affected abnormal livers. RESULTS: On evaluating the proposed technique on a database of 58 abnormal and 42 normal liver ultrasound images, the authors were able to achieve a high classification accuracy of 93.3% using the decision tree classifier. CONCLUSIONS: This high accuracy added to the completely automated classification procedure makes the authors' proposed technique highly suitable for clinical deployment and usage.

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This study deals with mastodont teeth found near Lisbon in Lower Langhian (lower Middle Miocene) fluviatile, feldspathic sands (Vb division). Conclusions are as follows: 1. Tetralophodont molars (even if at a still primitive stade of the tetralophodont condition) do exist at least since lower Langhian times, and not only since late Middle Miocene as was previously known. 2. Tri- and tetralophodont structures may (and indeed do) coexist in the same individual: such examples do not correspond to transitional forms, but instead to a mosaic of juxtaposed characters (however this does not mean there are no transitional forms in other instances). 3. So these structures coexisted in a population not yet genetically separated beyond fertile cross-breeding, i.e. beyond species' level. 4. Origin of the tetralophodont molar was due to some mutation (s). but without crossing species, limits and even more genus'ones. 5. At this times probably soon after the first appearance of tetralophodont mutants, animals with such characters were a small but significant minority among the population (17% if account is taken on D4's: only 2% after M2's). 6. There was not then any direct and clear correlation between number of lophs (transversal crests) and tooth size, even if the increase of such number goes along with length's increase. 7. Dimensions (length in special) in tetralophodont teeth tend to exceed those in «normal» trilophodont teeth, this being particularly clear in D4, even if there is no clear distinction: the situation is quite the same, maybe less marked, with the M2. 8. According to the preceding conclusions there are no reasons to segregate different taxa among such mastodont population on the grounds of the presence in D4, M1 and M2 of 3 or 4 crests (this character being regarded as diagnostic of the genus Tetralophodon). 9. On the contrary, if any natural (in biological sense) classification is disregarded and a morphological parataxonomy is adopted there should be considered both Gomphotherium angustidens and Tetralophodon sp.: however this is absolutely not our opinion.

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This study deals with mastodont teeth found near Lisbon in Lower Langhian (lower Middle Miocene) fluviatile, feldspathic sands (Vb division). Conclusions are as follows: 1. Tetralophodont molars (even if at a still primitive stade of the tetralophodont condition) do exist at least since lower Langhian times, and not only since late Middle Miocene as was previously known. 2. Tri- and tetralophodont structures may (and indeed do) coexist in the same individual: such examples do not correspond to transitional forms, but instead to a mosaic of juxtaposed characters (however this does not mean there are no transitional forms in other instances). 3. So these structures coexisted in a population not yet geneticaliy separated beyond fertile cross-breeding, i.e. beyond species'level. 4. Origin of the tetralophodont molar was due to some mutation (s). but without crossing species, limits and even more genus' ones. 5. At this times probably soon after the first appearance of tetralophodont mutants, animals with such characters were a small but signifiant minority among the population (17% if account is taken on D4's: only 2% after M2's). 6. There was not then any direct and clear correlation between number of lophs (transversal crests) and tooth size, even if the increase of such number goes along with length's increase. 7. Dimensions (length in special) in tetralophodont teeth tend to exceed those in «normal» trilophodont teeth, this being particularly clear in D4, even if there is no clear distinction: the situation is quite the same, maybe less marked, with the M2. 8. According to the preceding conclusions there are no reasons to segregate different taxa among such mastodont population on the grounds of the presence in D4, M1 and M2 of 3 or 4 crests (this character being regarded as diagnostic of the genus Tetralophodon). 9. On the contrary, if any natural (in biological sense) classification is disregarded and a morphological parataxonomy is adopted there should be considered both Gomphotherium angustidens and Tetralophodon sp.: however this is absolutely not our opinion.

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Teeth and astragali were used for a biometrical study concerning suids from V-a (upper Burdigalian) and V-b (Langhian) divisions from Lisbon's Miocene series. The Hyotherium (V-b) are identical to those from french localities, hence they all belong in the same species H. soemmeringi. Bunolistriodon populations from V-a and V-b are homogenous; no significant difference between them has been found, inspite of different geological age. Both may be ascribed to B. lockharti. No evolutive trend was detected. The presence of another form close to the north african B. massai could not be confirmed either. French localities' Bunolistriodon populations also seem homogenous and conspecific with those from Lisbon. Notwithstanding its essentially homogenous character, there can be distinguished two sets in both V-a and V-b populations according to M3 size; this remains to be explained, since the last molars are the most likely to show a broad range of variation and are not unequivocally related to sexual dimorphism. Classification of the rare Tayassuidae has been confirmed. All known taxa are shown (see tableau I).

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In practice the robotic manipulators present some degree of unwanted vibrations. The advent of lightweight arm manipulators, mainly in the aerospace industry, where weight is an important issue, leads to the problem of intense vibrations. On the other hand, robots interacting with the environment often generate impacts that propagate through the mechanical structure and produce also vibrations. In order to analyze these phenomena a robot signal acquisition system was developed. The manipulator motion produces vibrations, either from the structural modes or from endeffector impacts. The instrumentation system acquires signals from several sensors that capture the joint positions, mass accelerations, forces and moments, and electrical currents in the motors. Afterwards, an analysis package, running off-line, reads the data recorded by the acquisition system and extracts the signal characteristics. Due to the multiplicity of sensors, the data obtained can be redundant because the same type of information may be seen by two or more sensors. Because of the price of the sensors, this aspect can be considered in order to reduce the cost of the system. On the other hand, the placement of the sensors is an important issue in order to obtain the suitable signals of the vibration phenomenon. Moreover, the study of these issues can help in the design optimization of the acquisition system. In this line of thought a sensor classification scheme is presented. Several authors have addressed the subject of the sensor classification scheme. White (White, 1987) presents a flexible and comprehensive categorizing scheme that is useful for describing and comparing sensors. The author organizes the sensors according to several aspects: measurands, technological aspects, detection means, conversion phenomena, sensor materials and fields of application. Michahelles and Schiele (Michahelles & Schiele, 2003) systematize the use of sensor technology. They identified several dimensions of sensing that represent the sensing goals for physical interaction. A conceptual framework is introduced that allows categorizing existing sensors and evaluates their utility in various applications. This framework not only guides application designers for choosing meaningful sensor subsets, but also can inspire new systems and leads to the evaluation of existing applications. Today’s technology offers a wide variety of sensors. In order to use all the data from the diversity of sensors a framework of integration is needed. Sensor fusion, fuzzy logic, and neural networks are often mentioned when dealing with problem of combing information from several sensors to get a more general picture of a given situation. The study of data fusion has been receiving considerable attention (Esteban et al., 2005; Luo & Kay, 1990). A survey of the state of the art in sensor fusion for robotics can be found in (Hackett & Shah, 1990). Henderson and Shilcrat (Henderson & Shilcrat, 1984) introduced the concept of logic sensor that defines an abstract specification of the sensors to integrate in a multisensor system. The recent developments of micro electro mechanical sensors (MEMS) with unwired communication capabilities allow a sensor network with interesting capacity. This technology was applied in several applications (Arampatzis & Manesis, 2005), including robotics. Cheekiralla and Engels (Cheekiralla & Engels, 2005) propose a classification of the unwired sensor networks according to its functionalities and properties. This paper presents a development of a sensor classification scheme based on the frequency spectrum of the signals and on a statistical metrics. Bearing these ideas in mind, this paper is organized as follows. Section 2 describes briefly the robotic system enhanced with the instrumentation setup. Section 3 presents the experimental results. Finally, section 4 draws the main conclusions and points out future work.

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Semi quantification (SQ) in DaTScan® studies is broadly used in clinic daily basis, however there is a suspicious about its discriminative capability, and concordance with the diagnostic classification performed by the physician. Aim: Evaluate the discriminate capability of an adapted database and reference's values of healthy controls for the Dopamine Transporters (DAT) with 123I–FP-IT named DBRV adapted to Nuclear Medicine Department's protocol and population of Infanta Cristina's Hospital, and its concordance with the physician classification.

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RESUMO: A tese de doutoramento visa demonstrar duas proposições: a comorbilidade de 4 situações de doença prevalentes, hipertensão arterial (HTA), diabetes (DM), doença cardíaca isquémica (DCI) e asma é um assunto importante em Medicina Geral e Familiar e o seu estudo tem diversas implicações na forma como os cuidados de saúde são prestados, na sua organização e no ensino-aprendizagem da disciplina. O documento encontra-se dividido em 4 partes: 1) justificação do interesse do tema e finalidades da dissertação; 2) revisão sistemática de literatura publicada entre 1992 e 2002; 3) apresentação de dois trabalhos de investigação, descritivos e exploratórios que se debruçam sobre a mesma população de estudo, o primeiro intitulado “Comorbilidade de quatro doenças crónicas e sua relação com factores sócio demográficos” e o segundo, “Diferenças entre doentes, por médico e por sub-região, na comorbilidade de 4 doenças crónicas”; 4) conclusões e implicações dos resultados dos estudos na gestão da prática clínica, nos serviços, no ensino da disciplina da MGF e no desenvolvimento posterior de uma linha de investigação nesta área. O primeiro estudo tem como objectivos: descrever a prevalência da comorbilidade entre as 4 doenças-índice; verificar se existe relação entre o tempo da primeira doença e o tempo decorrido até ao aparecimento da 2ª e da 3ª doença, nas 4 doenças; determinar a comorbilidade associada às 4 doenças; identificar eventuais agrupamentos de doenças e verificar se existe relação entre comorbilidade e factores sociais e demográficos. O segundo estudo pretende verificar se existem diferenças na comorbilidade a nível local, por médico, e por Sub-Região de Saúde. O trabalho empírico é descritivo e exploratório. A população é constituída pelos doentes, com pelo menos uma das 4 doenças crónicas índice, das listas de utentes de 12 Médicos de Família a trabalharem em Centros de Saúde urbanos, suburbanos e rurais dos distritos de Lisboa e Beja. Os dados foram colhidos durante um ano através dos registos médicos. As variáveis sócio demográficas estudadas são: sexo, idade, etnia/raça, escolaridade, situação profissional, estado civil, tipo de família, funcionalidade familiar, condições de habitação. A comorbilidade é definida pela presença de duas ou mais doenças e estudada pelo número de doenças coexistentes. O tempo de duração da doença é definido como o número de anos decorridos entre o ano de diagnóstico e 2003. Os problemas de saúde crónicos são classificados pela ICPC2. Nas comparações efectuadas aplicaram-se os testes de Mann-Whitney e de Friedman, de homogeneidade e de análise de resíduos. A Análise Classificatória Hierárquica foi utilizada para determinar o agrupamento de doenças e a Análise de Regressão Categórica e Análise de Correspondências na relação entre as características sócio demográficas e a comorbilidade. Identificaram-se 3998 doentes. A idade média é de 64,3 anos (DP=15,70). Há uma correlação positiva significativa (r =0,350 r=0) entre “anos com a primeira doença”e “idade dos doentes” em todos os indivíduos (homens r=0,129 mulheres r=0,231). A comorbilidade entre as quatro doenças crónicas índice está presente em 1/3 da população. As associações mais prevalentes são HTA+DM (14,3%) e HTA+DCI (6,25%). Existe correlação positiva, expressiva, entre a duração da primeira doença, quando esta é a HTA ou a DM, e o intervalo de tempo até ao aparecimento da 2ª e da 3ª doenças. Identificaram-se 18 655 problemas crónicos de saúde que se traduziram em 244 códigos da ICPC2. O número médio de problemas foi de 5,94 (DP=3,04). A idade, a actividade profissional, a funcionalidade familiar e a escolaridade foram as variáveis que mais contribuíram para diferenciar os indivíduos quanto à comorbilidade. Foram encontradas diferenças significativas entre médicos(c2=1165,368 r=0) e entre os agrupamentos de doentes por Sub-Região de Saúde (c2= 157,108 r=0) no respeitante à comorbilidade. Na partição por Lisboa o número médio de problemas é de 6,45 e em Beja de 5,35. Deste trabalho ressaltam várias consequências para os profissionais, para os serviços, para o ensino e para a procura de mais saber nesta área. Os médicos, numa gestão eficiente de cuidados são chamados a desempenhar um papel de gestores da complexidade e de coordenadores assim como a trabalhar num modelo organizativo apoiado numa colaboração em equipa. Por sua vez os serviços de saúde têm que desenvolver medidas de avaliação de cuidados que integrem a comorbilidade como medida de risco. O contexto social da cronicidade e da comorbilidade deverá ser incluído como área de ensino. A concluir analisa-se o impacto do estudo nos colaboradores e o possível desenvolvimento da investigação nesta área.----------------------------------------ABSTRACT: The PhD Thesis has two propositions, co-morbidity of four chronic conditions (hypertension, asthma, diabetes, cardiac ischaemic disease) is a prevalent and complex issue and its study has several implications in the way care is provided and organised as well as in the learning and teaching of the discipline of General Practice. In the first part of the document arguments of different nature are given in order to sustain the dissertation aims; the second part describes a systematic study of literature review from 1992 to 2002; the third presents two research studies "Comorbidity of four chronic diseases and its relation with socio demographic factors” and “Differences between patients among GPs at local and regional level”; implications of study results for practice management, teaching and research are presented in the last part. The prevalence of the four chronic diseases co-morbidity, the relation of the first disease duration with the time of diagnose of the next index condition, the burden of co-morbidity in the four chronic diseases, the clustering of those diseases, the relation between demographic and social characteristics and co-morbidity, are the objectives of the first study. The second intends to verify differences in comorbidity between patients at local and regional level of practice. Research studies were descriptive and exploratory. The population under study were patients enlisted in 12 GPs working in urban and rural health centres, in Lisbon and Beja districts, with at least one of the four mentioned diseases. Data were collected through medical records during one year (2003) and 3998 patients were identified. The social demographic variables were: sex, age, ethnicity/race, education, profession, marriage status, family status, family functionality, home living conditions. Co-morbidity is defined by the presence of two or more diseases, and studied by the number of co-existing diseases. The time duration of the disease is defined by the number of years between the diagnostic year and 2003. The chronic disease problems are classified in accord with ICPC2. The characterization of population is descriptive. The effected comparisons applied the Mann-Whitney, Friedman, homogeneity and analysis of residuals tests. The Classificatory Hierarchy Analysis was utilized to determine the grouping of diseases and the Regression Categorization and Correspondences Analysis was used to study the relation of socio-demographic and co-morbidity. The median age of the population under study is 64,3 (SD= 15,70). There is a significant positive correlation (r =0,350 r=0)between “years with the first disease” and “patient age” for all individuals (men r=0,129 women r=0,231). Co-morbidity of the four index diseases is present in 1/3 of the studied population. The most prevalent associations for the four diseases are HTA+DM (14,03%) and HTA+IHD (6,25%). Expressive positive correlation between the duration of the first disease and the second and the third index disease interval is found. For the 3988 patients, 18 655 chronic health problems, translated in 244 ICPC2 codes, were identified. The mean number of problems is 5,94 (SD=3,04). Age, professional activity, family functionality and education level are the socio demographic characteristics that most contribute to differentiate individuals concerning the overall co-morbidity. Significant differences in co-morbidity between GP patients at local (c2=1165,368 r=0) and regional level (c2= 157,108 r=0) are found. This study has several consequences for professionals, for services, for the teaching and learning of General Practice and for the pursuit of knowledge in this area. New competences and performances have to be implemented. General Practitioners, assuming a role of co-ordination, have to perform the role of complexity managers in patient's care, working in practices supported by a strong team in collaboration with other specialists. In order to assess provided care, services have to develop tools where co-morbidity is included as a risk measure. The social context of comorbidity and chronicity has to be included in the curricula of General Practice learning and teaching areas. The dissertation ends describing the added value to participant's performance for their participation in the research and an agenda for further research, in this area, based on a community of practice.--------RÉSUMÉ:Cette thèse de doctorat prétend démontrer deux postulats : le premier, que la comorbidité de quatre maladies fréquentes, hypertension artérielle (HTA), diabète (DM), maladie cardiaque ischémique (DCI) et asthme, est un thème important en Médecine Générale et Familiale et que son étude a plusieurs implications au niveau de l'approche pour dispenser les soins, de leur organisation et de l'enseignement/apprentissage de la discipline. Le document comprend quatre parties distinctes : 1) justification de l'intérêt du sujet et objectifs de la dissertation ; 2) étude systématique de publications éditées entre 1992 et 2002 ; 3) présentation de deux travaux de recherche, descriptifs et exploratoires, un premier intitulée « Comorbidité de quatre maladies chroniques et leur relation avec des facteurs sociodémographiques » et un deuxième « Différences entre malades, selon le médecin et la sous région, dans la comorbilité de quatre maladies chroniques» ; 4) conclusions et conséquences des résultats des études dans la gestion de la pratique clinique, dans les services, dans l'enseignement de la discipline de MGF et dans le développement postérieur de la recherche dans ce domaine. Les objectifs de la première étude sont les suivants : décrire la prévalence de la comorbidité entre les quatre maladies chroniques, vérifier s'il existe une relation entre temps de durée de la première maladie et l'espace de temps jusqu'à le diagnostic de la 2ème ou 3ème maladie; déterminer la comorbidité entre les 4 maladies ; identifier d'éventuelles groupements de maladies et vérifier s'il existe une relation entre comorbidité et facteurs sociodémographiques. La deuxième étude prétend vérifier s'il existe des différences de comorbidité entre médecins et par groupement régional. Le travail empirique est descriptif et exploratoire. La population est composée des malades ayant au moins une des quatre maladies chroniques parmi les listes de malades de douze Médecins de Famille qui travaillent dans des Centres de Santé urbains, suburbains et ruraux (Districts de Lisbonne et Beja). Les données ont été extraites pendant l'année 2003 des registres des médecins. Les variables sociodémographiques étudiées sont : le sexe, l'âge, l'ethnie/race, la scolarité, la situation professionnelle, l'état civil, le type de famille, sa fonctionnalité, les conditions de logement. La comorbidité est définie lorsqu'il existe deux ou plusieurs maladies et est étudiée d'après le nombre de maladies coexistantes. La durée de la maladie est établie en comptant le nombre d'années écoulées entre le diagnostique et 2003. Les problèmes de santé chroniques sont classés par l'ICPC 2. Pour les comparaisons les tests de Mann-Whitney et Friedman, de homogénéité et analyse de résidues ont été appliqués. L'Analyse de Classification Hiérarchique a été utilisée pour procéder au regroupement des maladies et l'Analyse de Régression Catégorique et l'Analyse de Correspondances pour étudier la relation entre les caractéristiques sociodémographiques et la comorbilité. Les principaux résultats sont les suivants : les 3998 malades identifiés ont 64,3 ans d'âge moyen (DP=15,70). Il existe une corrélation positive significative (r =0,350 r=0) entre « les années avec la première maladie » et « l'âge des malades », chez tous les individus (hommes r=0,129 femmes r=0,231). La comorbidité entre les quatre maladies chroniques est une réalité chez 1/3 des patients. Les associations les plus fréquentes sont HTA+DM (14%) et HTA+DCI (6,25%). Il existe une corrélation positive significative entre la durée de la première maladie, HTA ou DM, et l'écart jusqu'à l'apparition de la deuxième et de la troisième maladie. Chez les malades, 18.655 problèmes chroniques de santé ont été identifiés et traduits en 244 codes de l'ICPC2. La moyenne des problèmes a été de 5,94 (DP=3,04). L'âge, l'activité professionnelle, la fonctionnalité familiale et la scolarité sont les variables qui ont le plus contribué à différencier les individus face à la comorbilité. Des différences notoires ont été trouvées entre médecins (c2=1165,368 r=0) et entre les groupements régionaux (c2=157,108 r=0) en ce qui concerne la comorbidité. Dans le groupe de patients de Lisbonne, le chiffre moyen de problèmes est de 6,45 et à Beja il est de 5,35. Cette étude met en évidence plusieurs conséquences pour les professionnels, les services, l'enseignement et l'élargissement du savoir dans ce domaine. Les médecins, soucieux de gérer efficacement les soins sont appelés à jouer un rôle de gestionnaires de la complexité et de coordinateurs, de même qu'à travailler dans un modèle d'organisation soutenus par un travail d'équipe. D'autre part, les services de santé doivent eux aussi développer des mesures d'évaluation des soins qui intègrent la comorbidité comme mesure de risque. Le contexte social de la chronicité et de la comorbidité devra être inclus comme domaines à étudier. La fin de cette thèse décrit l'impact de cette étude sur les collaborateurs et le développement futur de la recherche dans ce domaine.