Em análise de sobrevivência, usualmente o interesse esté em estudar o tempo até a ocorrência de um evento. Quando as observações estão sujeitas a mais de um tipo de evento (por exemplo, diferentes causas de óbito) e a ocorrência de um evento impede a ocorrência dos demais, tem-se uma estrutura de riscos competitivos. Em algumas situações, no entanto, o interesse está em estudar dois eventos, sendo que um deles (evento terminal) impede a ocorrência do outro (evento intermediário), mas não vice-versa. Essa estrutura é conhecida como riscos semicompetitivos e foi definida por Fine et al.(2001). Neste trabalho são consideradas duas abordagens para análise de dados com essa estrutura. Uma delas é baseada na construção da função de sobrevivência bivariada por meio de cópulas da família Arquimediana e estimadores para funções de sobrevivência são obtidos. A segunda abordagem é baseada em um processo de três estados, conhecido como processo doença-morte, que pode ser especificado pelas funções de intensidade de transição ou funções de risco. Neste caso, considera-se a inclusão de covariáveis e a possível dependência entre os dois tempos observados é incorporada por meio de uma fragilidade compartilhada. Estas metodologias são aplicadas a dois conjuntos de dados reais: um de 137 pacientes com leucemia, observados no máximo sete anos após transplante de medula óssea, e outro de 1253 pacientes com doença renal crônica submetidos a diálise, que foram observados entre os anos 2009-2011. / In survival analysis, usually the interest is to study the time until the occurrence of an event. When observations are subject to more than one type of event (e.g, different causes of death) and the occurrence of an event prevents the occurrence of the other, there is a competing risks structure. In some situations, nevertheless, the main interest is to study two events, one of which (terminal event) prevents the occurrence of the other (nonterminal event) but not vice versa. This structure is known as semicompeting risks, defined initially by Fine et al. (2001). In this work, we consider two approaches for analyzing data with this structure. One approach is based on the bivariate survival function through Archimedean copulas and estimators for the survival functions are obtained. The second approach is based on a process with three states, known as Illness-Death process, which can be specified by the transition intensity functions or risk functions. In this case, the inclusion of covariates and a possible dependence between the two times is taken into account by a shared frailty. These methodologies are applied to two data sets: the first one is a study with 137 patients with leukemia that received an allogeneic marrow transplant, with maximum follow up of 7 years; the second is a data set of 1253 patientswith chronic kidney disease on dialysis treatment, followed from 2009 until 2011.

INTRODUÇÃO: A avaliação geriátrica ampla promove uma triagem programada das síndromes e alterações mais comuns nos idosos. Este instrumento multidimensional apresenta excelente desempenho na identificação precoce de pacientes em risco para desfechos adversos. No entanto, tempo e recursos limitados impedem o seu uso em serviços de saúde concorridos, em especial aqueles que oferecem cuidados agudos. OBJETIVOS: Desenvolver e investigar as propriedades psicométricas de uma avaliação geriátrica compacta de 10 minutos (AGC-10) para idosos em serviços de saúde ocupados. MÉTODOS: Na primeira etapa, um consenso de especialistas (técnica Delphi) composto por 62 geriatras de todas as regiões do Brasil desenvolveu o instrumento. Na segunda etapa, as propriedades psicométricas da AGC-10 foram investigadas em uma coorte prospectiva envolvendo 534 idosos com doenças agudas ou crônicas descompensadas (média de 79,5 ± 8,4 anos de idade; 63% mulheres) consecutivamente admitidos em um hospital dia de um centro médico acadêmico, em São Paulo, Brasil. A AGC-10 foi administrada na admissão. O Frailty Index e o fenótipo de fragilidade foram usados para explorar a validade da AGC-10. Houve seguimento de um ano por contato telefônico mensal para aferição dos desfechos perda funcional para atividades básicas de vida diária (ABVD), hospitalização e morte. Modelos de riscos proporcionais, que consideraram morte como um evento competitivo, associaram a AGC-10 com os desfechos adversos após ajuste para fatores sociodemográficos (idade, sexo, raça e renda) e índice de comorbidades de Charlson. A confiabilidade interexaminadores e o tempo para administrar o instrumento foram examinados em uma subamostra representativa de 53 participantes. RESULTADOS: Em três rodadas de opinião, os especialistas de 32 instituições diferentes estabeleceram consenso de que a AGC-10 deveria incluir 10 domínios (suporte social, hospitalizações recentes, quedas, número de medicamentos, ABVD, cognição, autoavaliação da saúde, sintomas depressivos, estado nutricional e velocidade de marcha). Houve acordo sobre os instrumentos específicos para avaliar cada domínio. Um índice total de 0 a 1 expressou a média dos déficits encontrados nos 10 domínios e classificou os pacientes em três níveis: baixo (0-0,29), médio (0,3-0,39) e alto (0,4-1) risco. O índice AGC-10 correlacionou-se fortemente com o Frailty Index (coeficiente de Spearman=0,79; IC95%=0,76-0,82) e apresentou acurácia excelente para identificar indivíduos frágeis (área sob a curva ROC=0,84 IC95%=0,81-0,87). Em comparação aos de baixo risco, pacientes classificados como médio e alto risco na AGC-10 tiveram maior incidência de perda funcional (33% vs. 13%, sub-HR=2,3 IC95%=1,3-4,0; 51% vs. 13%, sub-HR=4,1 IC95%=2,4-6,9, respectivamente), hospitalização (44% vs. 22%, sub-HR=2,4 IC95%=1,5-3,9; 51% vs. 22%, sub-HR=3,2 IC95%=2,0-4,9, respectivamente) e morte (18% vs. 5%, HR=2,9 IC95%=1,2-7,3; 24% vs. 5%, HR=3,9 IC95%=1,7-9,3, respectivamente) em um ano. O índice AGC-10 mostrou excelente confiabilidade interexaminadores (coeficiente de correlação intraclasse=0,92 IC95%=0,87-0,95). O tempo médio de administração do novo instrumento foi de 9,5 ± 2,2 minutos. CONCLUSÕES: O estudo apresenta evidências robustas que sustentam a validade e confiabilidade da AGC-10. Este instrumento de rastreio multidimensional breve pode ser uma opção prática e eficiente para identificar condições geriátricas, prever desfechos adversos e guiar os cuidados dos idosos em serviços de saúde em que os profissionais tenham limitação de tempo e recursos / BACKGROUND: Comprehensive geriatric assessment promotes a systematic screening of the geriatric syndromes and other health problems that commonly affect older adults. This multidimensional instrument has excellent performance to identify high-risk older patients for adverse outcomes. However, limited time and resources hinder its use in busy healthcare settings. OBJECTIVES: To develop and investigate the psychometric properties of a 10-minute targeted geriatric assessment (10-TaGA) designed for older adults in fast-paced healthcare settings. METHODS: A consensus of experts (Delphi technique) comprising 62 geriatrics from all regions of Brazil developed the instrument. We investigated the psychometric properties of 10-TaGA in a prospective cohort study involving 534 acutely ill older outpatients (mean age 79,5 ± 8,4 years; 63% female) consecutively admitted to a day hospital at an academic medical center, in Sao Paulo, Brazil. The 10-TaGA was administered on admission. The Frailty index and Physical Frailty Phenotype were used to explore 10-TaGA\'s validity. We conducted 1-year follow-up by monthly phone contacts to assess the outcomes, which included new dependence in basic activities of daily living (ADL), hospitalization, and death. Hazard models, considering death as a competing event, were used to associate 10-TaGA with the adverse outcomes after adjusting for sociodemographic factors (age, sex, race, and income) and Charlson comorbidity index. The interrater reliability and time to complete the instrument were evaluated in a 53-person representative subsample. RESULTS: In three rounds of opinion, experts from 32 institutions achieved consensus that the 10-TaGA should include 10 domains (social support, recent hospitalizations, falls, number of medications, ADL, cognition, self-rated health, depressive symptoms, nutritional status, and gait speed). They arrived at sufficient agreement on specific tools to evaluate each domain. A single numerical score from 0 to 1 expressed the cumulative deficits across the 10 domains and classified participants into three levels: low (0-0.29), medium (0.3-0.39), and high (0.4-1) risk. The 10-TaGA score was highly correlated with the Frailty Index (Spearman coefficient=0.79, 95CI%=0.76-0.82) and had an excellent accuracy to identify frail older adults (area under the ROC curve=0.84, 95%CI=0.81-0.87). Compared to low-risk patients, those classified as medium-risk and high-risk according to 10-TaGA presented a higher incidence of new ADL dependence (33% vs. 13%, sub- HR=2.3, 95%CI=1.3-4.0; 51% vs. 13%, sub-HR=4.1, 95%CI=2.4-6.9, respectively), hospitalization (44% vs. 22%, sub-HR=2.4, 95%CI=1.5-3.9; 51% vs. 22%, sub-HR=3.2, 95%CI=2.0-4.9, respectively) e death (18% vs. 5%, HR=2.9, 95%CI=1.2-7.3; 24% vs. 5%, HR=3.9, 95%CI=1.7-9.3, respectively) during the 1-year follow-up period. The 10-TaGA score had excellent interrater reliability (intraclass correlation coefficient=0.92, 95%CI=0.87-0.95). Mean time to administer the instrument was 9.5 ± 2.2 minutes. CONCLUSIONS: The study presents robust evidence supporting 10-TaGA\'s validity and reliability. This brief multidomain screener tool may be a practical and efficient approach to identify geriatric syndromes, predict adverse outcomes, and guide the care of older adults in healthcare settings where providers have limited time and resources

La survie nette est un indicateur incontournable pour juger du control du cancer. Par définition, elle correspond à la survie que l’on observerait dans un monde hypothétique où le cancer étudié serait la seule cause possible de décès. L’objectif principal de cette thèse était de montrer l’intérêt de cet indicateur dans le cadre de la recherche clinique en prenant en compte quelques défis méthodologiques qui peuvent être rencontrés dans ce contexte. Nous avons présenté d’abord le concept de survie nette et ses méthodes d’estimation. Par la suite nous nous sommes intéressés à quelques problématiques rencontrées dans les essais cliniques à long terme lorsque l’on s’intéresse à l’estimation de la survie nette. Nous avons étudié également l’impact de l’utilisation de l’approche classique d’estimation de la survie nette dans les essais cliniques, i.e. la méthode cause-spécifique dans différentes configurations d’erreurs de classifications de la cause de décès. La deuxième problématique de cette thèse a porté sur la prise en compte du biais de sélection en termes de mortalité autres causes des patients. Nous avons proposé un modèle de mortalité en excès prenant en compte ce type de biais de sélection. Une troisième problématique qui est complémentaire à la deuxième est de prendre en compte inter-centres en même temps que le biais de sélection. Ce travail propose ainsi de nouveaux outils pouvant aider les spécialistes de la recherche clinique à évaluer de nouvelles stratégies thérapeutiques dans les essais cliniques en cancérologie, mais aussi dans d’autres domaines cliniques d’applications. / Net survival is a key indicator for measuring cancer control. By definition, it corresponds to the survival that would be observed in a hypothetical world where the cancer studied is the only possible cause of death. The main objective of this thesis was to show the interest of this indicator in the context of clinical research taking into account some methodological challenges that can be encountered. In this work, we have first presented the concept of net survival and its estimation methods. Subsequently, we were interested in some of the problems encountered in long-term clinical trials when the interest is in estimating net survival. We studied the impact of using the classic approach when estimating net survival in clinical trials, i.e. the cause-specific method in different configurations of misclassifications of the cause of death. The second objective of this thesis was to take into account the selection bias in terms of other causes mortality in the modeling of excess mortality, because of the noncomparability between patients from general population and those of clinical trials. We proposed an excess hazard model that corrects this type of selection bias. A third problem which is complementary to the second is to take into account the heterogeneity of patients in the different recruitment centers at the same time as the selection bias. This work proposes new tools which can help clinical research specialists to evaluate new therapeutic strategies in cancer clinical trials, but also in other areas of clinical application.

<p>This thesis investigates health trends among very old people and the allocation of public home-help services. A further aim is to examine methodological issues in mortality analysis. Three data sources are used: (1) The Tierp study of community-dwelling persons (n=421, ages 75+), (2) the SWEOLD nationally representative samples (n=537 in 1992 and n=561 in 2002, ages 77+), and 3) SNAC-K comprised of home-help recipients in a district of Stockholm (n=1108, ages 65+).</p><p>Study I suggests that the length of the follow-up period may explain some of the differences found in predictor strength when comparing mortality studies. Predictors that can change rapidly (e.g., health) were found to be strongest for the short term, with a lower average mortality risk for longer follow-ups. Stable variables (e.g., gender) were less affected by length of follow-up.</p><p>Studies II and III present a measure of complex health problems based on serious problems in at least two of three health domains. These were diseases/symptoms, mobility, and cognition/communication. Prevalence of complex health problems increased significantly between 1992 and 2002. Older age, female gender, and lower education increased the odds of having complex problems. Complex problems strongly predicted 4-year mortality. Controlled for age, gender, health, and education, mortality decreased by 20% between 1992 and 2002. Men with complex problems accounted for this decrease. Thus, in 2002 the gender difference in mortality risk was almost eliminated among the most vulnerable adults.</p><p>Study IV revealed that physical and cognitive limitations, higher age, and living alone were significantly related to home-help allocation, with physical and cognitive limitations dominating. Psychiatric symptoms did not affect the assessment.</p><p>The increased prevalence of complex health problems and increased survival among people with complex needs have important implications concerning the need for collaboration among service providers.</p>

This thesis investigates health trends among very old people and the allocation of public home-help services. A further aim is to examine methodological issues in mortality analysis. Three data sources are used: (1) The Tierp study of community-dwelling persons (n=421, ages 75+), (2) the SWEOLD nationally representative samples (n=537 in 1992 and n=561 in 2002, ages 77+), and 3) SNAC-K comprised of home-help recipients in a district of Stockholm (n=1108, ages 65+). Study I suggests that the length of the follow-up period may explain some of the differences found in predictor strength when comparing mortality studies. Predictors that can change rapidly (e.g., health) were found to be strongest for the short term, with a lower average mortality risk for longer follow-ups. Stable variables (e.g., gender) were less affected by length of follow-up. Studies II and III present a measure of complex health problems based on serious problems in at least two of three health domains. These were diseases/symptoms, mobility, and cognition/communication. Prevalence of complex health problems increased significantly between 1992 and 2002. Older age, female gender, and lower education increased the odds of having complex problems. Complex problems strongly predicted 4-year mortality. Controlled for age, gender, health, and education, mortality decreased by 20% between 1992 and 2002. Men with complex problems accounted for this decrease. Thus, in 2002 the gender difference in mortality risk was almost eliminated among the most vulnerable adults. Study IV revealed that physical and cognitive limitations, higher age, and living alone were significantly related to home-help allocation, with physical and cognitive limitations dominating. Psychiatric symptoms did not affect the assessment. The increased prevalence of complex health problems and increased survival among people with complex needs have important implications concerning the need for collaboration among service providers.

Syftet var att granska sjuksköterskans dokumentation avseende intagningsorsak, andra identifierade problem/behov utefter CGA och vilka åtgärder det ledde till samt beskriva sjuksköterskans erfarenheter av att använda instrumentet CGA. Metod: Studien har en beskrivande design med kvantitativ och kvalitativ ansats. Totalt granskades 50 bedömningsinstrument och datajournaler. Frågeformulär utformades och 13 sjuksköterskor valde att delta. Journalgranskningarna utfördes med kvantitativ retrospektiv analys och frågeformulären analyserades enligt kvalitativ manifest innehållsanalys. Resultat: Under journalgranskningen framkom 11 olika intagningsorsaker där försämrat allmäntillstånd var den största gruppen. Totalt identifierades 205 problem/behov och 186 initierade åtgärder varav 7 åtgärder/person var högsta antal. Flest initierade åtgärder fanns inom nutrition, social bakgrund och fallrisk. Sjuksköterskornas erfarenheter av att använda CGA var att det fanns behov av tydliga arbetsrutiner gällande CGA, att CGA fungerade bra som checklista men var tidskrävande. De upplevde att CGA gav dubbelarbete men viljan fanns att använda CGA men däremot svårt att få det att fungera i arbetet samt att sjuksköterskorna identifierade problem/behov utan att använda CGA. Sjuksköterskorna upplevde inte att omhändertagandet förändrades men däremot fick teamet helhetsperspektiv på patientens livssituation. Samverkan med anhöriga och kommunen var viktigt. Slutsats: Studiens resultat visade att förutom inskrivningsorsak fanns även andra identifierade problem/behov utefter CGA som hade stor betydelse för att den äldre skulle uppleva hälsa. Sjuksköterskorna upplevde brister inom rutinen runt CGA samt erfor att sjuksköterskornas omhändertagande av den geriatriska patienten inte förändrades efter implementeringen av CGA. / Aim was to examine nurses documentation regarding admission cause, other identified problems/needs by the CGA and the actions that led to and describe nurses experiences of using the instrument CGA. Method: The study has a descriptive design with quantitative and qualitative approach. Total audited 50 assessment instruments and data records. Questionnaires were designed and 13 nurses chose to participate. Journal audits performed by quantitative retrospective analysis and the questionnaires were analyzed by the inspiration of qualitative manifest content analysis. Results: In the journal audit identified 11 different admission causes which reduced general condition was the largest group. Total identified 205 problems/needs and 186 initiated measures which 7 action/person was the highest number. Most measures were initiated in nutrition, social background and risk of falling. Nurses experiences of using the CGA was that there was a need for clear work procedures regarding the CGA, the CGA worked well as a checklist but was time consuming. They felt that the CGA gave duplication but the desire was to use the CGA but hard to make it work at work and the nurses identified problems / needs without using the CGA. The nurses did not feel that the care was changed but got the team holistic view of the patients life situation. Collaboration with families and the municipality was important. Conclusion: The study results showed that in addition the cause enrollment were other identified problems/needs along the CGA that had great importance for the elderly would experience health. The nurses experienced deficiencies in routine around the CGA and required that the nurses taking care of the geriatric patient did not change after the implementation of CGA.

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-08-29T19:13:47Z No. of bitstreams: 1 TeseLHMM.pdf: 2605456 bytes, checksum: b07c268a8fc9a1af8f14ac26deeec97e (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-09-25T18:22:48Z (GMT) No. of bitstreams: 1 TeseLHMM.pdf: 2605456 bytes, checksum: b07c268a8fc9a1af8f14ac26deeec97e (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-09-25T18:22:55Z (GMT) No. of bitstreams: 1 TeseLHMM.pdf: 2605456 bytes, checksum: b07c268a8fc9a1af8f14ac26deeec97e (MD5) / Made available in DSpace on 2017-09-25T18:27:54Z (GMT). No. of bitstreams: 1 TeseLHMM.pdf: 2605456 bytes, checksum: b07c268a8fc9a1af8f14ac26deeec97e (MD5) Previous issue date: 2017-04-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Conventional reliability analysis techniques are focused on the occurrence of failures over time. However, in certain situations where the occurrence of failures is tiny or almost null, the estimation of the quantities that describe the failure process is compromised. In this context the degradation models were developed, which have as experimental data not the failure, but some quality characteristic attached to it. Degradation analysis can provide information about the components lifetime distribution without actually observing failures. In this thesis we proposed different methodologies for degradation data based on the inverse Gaussian distribution. Initially, we introduced the inverse Gaussian deterioration rate model for degradation data and a study of its asymptotic properties with simulated data. We then proposed an inverse Gaussian process model with frailty as a feasible tool to explore the influence of unobserved covariates, and a comparative study with the traditional inverse Gaussian process based on simulated data was made. We also presented a mixture inverse Gaussian process model in burn-in tests, whose main interest is to determine the burn-in time and the optimal cutoff point that screen out the weak units from the normal ones in a production row, and a misspecification study was carried out with the Wiener and gamma processes. Finally, we considered a more flexible model with a set of cutoff points, wherein the misclassification probabilities are obtained by the exact method with the bivariate inverse Gaussian distribution or an approximate method based on copula theory. The application of the methodology was based on three real datasets in the literature: the degradation of LASER components, locomotive wheels and cracks in metals. / As técnicas convencionais de análise de confiabilidade são voltadas para a ocorrência de falhas ao longo do tempo. Contudo, em determinadas situações nas quais a ocorrência de falhas é pequena ou quase nula, a estimação das quantidades que descrevem os tempos de falha fica comprometida. Neste contexto foram desenvolvidos os modelos de degradação, que possuem como dado experimental não a falha, mas sim alguma característica mensurável a ela atrelada. A análise de degradação pode fornecer informações sobre a distribuição de vida dos componentes sem realmente observar falhas. Assim, nesta tese nós propusemos diferentes metodologias para dados de degradação baseados na distribuição gaussiana inversa. Inicialmente, nós introduzimos o modelo de taxa de deterioração gaussiana inversa para dados de degradação e um estudo de suas propriedades assintóticas com dados simulados. Em seguida, nós apresentamos um modelo de processo gaussiano inverso com fragilidade considerando que a fragilidade é uma boa ferramenta para explorar a influência de covariáveis não observadas, e um estudo comparativo com o processo gaussiano inverso usual baseado em dados simulados foi realizado. Também mostramos um modelo de mistura de processos gaussianos inversos em testes de burn-in, onde o principal interesse é determinar o tempo de burn-in e o ponto de corte ótimo para separar os itens bons dos itens ruins em uma linha de produção, e foi realizado um estudo de má especificação com os processos de Wiener e gamma. Por fim, nós consideramos um modelo mais flexível com um conjunto de pontos de corte, em que as probabilidades de má classificação são estimadas através do método exato com distribuição gaussiana inversa bivariada ou em um método aproximado baseado na teoria de cópulas. A aplicação da metodologia foi realizada com três conjuntos de dados reais de degradação de componentes de LASER, rodas de locomotivas e trincas em metais.

Made available in DSpace on 2016-06-02T20:19:22Z (GMT). No. of bitstreams: 1 5752.pdf: 3964062 bytes, checksum: 16f3900bb64941a8187a1e82a73149df (MD5) Previous issue date: 2014-02-18 / Background: Frailty is a critical state of physiological complexity loss. Evaluation measures of complexity could contribute for a better comprehension regarding the frailty process. Objective: to evaluate complexity of HRV, at rest and after postural change, on frailty syndrome. Design: cross-sectional. Setting: community. Subjects: 100 individuals over 60 years old, distributed in groups according to the frailty phenotype: frail (n=8), pre-frail (n=46) and non-frail (n=46). Methods: The electrocardiogram was made in supine and orthostatic postures, for 10 minutes in each position. Sequences of 256 RR intervals were analyzed through linear (spectral analysis low frequency in normalized units (LFnu) and high frequency in absolute units (HFabs)) and non-linear methods (symbolic analysis 0V% and 2UV%, Shannon entropy (SE), conditional entropy (normalized complexity index NCI)). Results: The NCI did not show difference among the evaluated groups in rest supine, however NCI presented reduced values in all 3 groups after orthostatic challenge. Except AFabs, other indices did not differ between groups at rest supine. Conclusion: The results of this study indicate that there is no decrease of complexity on frailty syndrome, possibly because it already presents decreased values with the senescence. The postural change was unable to detect any impairment in HRV complexity associated with the frailty process. / A fragilidade é um estado crítico de perda da complexidade fisiológica, que resulta em maior vulnerabilidade. Medidas de avaliação da complexidade poderiam contribuir para melhor compreensão sobre o processo de fragilização. Objetivo: avaliar a complexidade da variabilidade da frequência cardíaca (VFC), em repouso e após mudança postural, na síndrome da fragilidade. Desenho experimental: estudo transversal. Ambiente de pesquisa: comunidade. Sujeitos: 100 idosos maiores de 60 anos, divididos em grupos, segundo o fenótipo da fragilidade: frágil (n=8), pré-frágil (n=46) e não-frágil (n=46). Métodos: O eletrocardiograma foi coletado na postura supina e ortostática, por 10 minutos em cada posição. Trechos de 256 intervalos RR foram analisados por metodologias lineares (análise espectral baixa frequência em unidades normalizadas (BFun) e alta frequência em unidades absolutas (AFabs)), bem como não lineares (análise simbólica - 0V% e 2VD%, entropia de Shannon (ES), entropia condicional (índice de complexidade normalizado - ICN)). Resultados: o ICN não apresentou diferenças entre os grupos avaliados, no entanto teve seus valores reduzidos em todos os grupos após a mudança postural. Com exceção da AFabs, os demais índices não diferiram entre os grupos, na condição de repouso supino. Conclusão: Os resultados deste estudo indicam que não há redução da complexidade na síndrome da fragilidade, possivelmente pelo fato desta já apresentar valores reduzidos na senescência. A resposta da complexidade cardíaca à mudança postural não apresentou diferenças na presença da síndrome da fragilidade.

Made available in DSpace on 2016-06-02T20:19:25Z (GMT). No. of bitstreams: 1 6555.pdf: 1289563 bytes, checksum: 019c580e1b818068847725c1d7aeadfa (MD5) Previous issue date: 2015-02-05 / Universidade Federal de Minas Gerais / Frailty is related to a decrease in the physiological reserves that causes a difficult to maintain homeostasis. The analysis of heart period (HP) and blood pressure (BP) variabilities can contribute to the understanding of cardiovascular homeostasis in the frailty syndrome. Objective: To compare HP and BP variabilities in frail, prefrail and nonfrail, un supine and orthostatic positions, by univariate and bivariate analysis. Methods: 39 elderly were evaluated and distributed in frail, prefrail and nonfrail groups, accordingly to frailty phenotype. The RR interval (RRi) and the systolic BP (SBP) series were registered for 15 minutes in the supine position and 15 minutes in orthostatic position. Univariate analysis (RRi: mean, variance, LFnu, HFabs and LF/HF and the SBP: mean, variance and LFabs) and bivariate analysis (phase, gain (&#945;) and coherence (K2)) were performed. A two-way repeated measures ANOVA test was used for the statistical analysis; a 5% significance level was considered, along with group, position and interaction effects. Results: Univariate analysis do not detected changes in frailty syndrome. However, in the bivariate analysis frail presented lower K² than nonfrail in orthostatic position. Prefrail and frail reported a significant decrease in K² values in orthostatic position in comparison to the supine. Conclusion: Univariate analysis of HP and BP variabilities do not change when frailty syndrome is present. However, bivariate analysis indicated decoupling between HP and BP in frailty presence. Thus, a reduced K2 might be a marker of frailty process. / A fragilidade está associada à redução das reservas fisiológicas que leva à dificuldade na manutenção da homeostase. A análise da variabilidade da frequência cardíaca (FC) e da pressão arterial (PA) pode contribuir para a compreensão da homeostase cardiovascular na síndrome da fragilidade. Objetivo: Comparar a variabilidade da frequência cardíaca (VFC) e a variabilidade da pressão arterial sistólica (VPA) de indivíduos frágeis, pré-frágeis e robustos, nas posturas supina e ortostática, utilizando-se de análises univariada e bivariada. Métodos: Foram avaliados 39 idosos, alocados em 3 grupos de acordo com o fenótipo da fragilidade. As séries de intervalos RR (iRR) e de PA sistólica (PAS) foram registradas por 15 minutos em repouso na posição supina, e 15 minutos na posição ortostática. Foram realizadas as análises univariada (iRR: média, variância, baixa frequência em unidades normalizadas (BFun), alta frequência em unidades absolutas (AFabs) e razão entre a baixa e alta frequência (BF/AF) e PAS: média, variância e BFabs) e bivariada (fase, ganho (&#945;) e coerência (K2)). Para análise estatística foi utilizado o teste Anova two way de medidas repetidas, com efeitos de grupo, posição e interação entre estes, considerando um nível de significância de 5%. Resultados: A análise univariada não detectou alterações na síndrome da fragilidade. Entretanto, na análise bivariada os frágeis apresentaram menores valores de K2 em comparação aos robustos na posição ortostática. Préfrágeis e frágeis apresentaram redução significativa nos valores de K2 na posição ortostática em comparação à supina. Conclusão: A variabilidade da FC e da PA, avaliada pela análise univariada, não se altera quando a fragilidade está presente. Por sua vez, a análise bivariada indicou um maior desacoplamento entre FC e PA na presença da síndrome da fragilidade. Desta forma, a K2 reduzida pode ser um marcador do processo de fragilização.

Submitted by Daniele Amaral (daniee_ni@hotmail.com) on 2016-09-15T15:15:11Z No. of bitstreams: 1 DissCCF.pdf: 1472861 bytes, checksum: 937810926b98a08677085a559d13aec9 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:51:30Z (GMT) No. of bitstreams: 1 DissCCF.pdf: 1472861 bytes, checksum: 937810926b98a08677085a559d13aec9 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:51:36Z (GMT) No. of bitstreams: 1 DissCCF.pdf: 1472861 bytes, checksum: 937810926b98a08677085a559d13aec9 (MD5) / Made available in DSpace on 2016-09-16T19:51:41Z (GMT). No. of bitstreams: 1 DissCCF.pdf: 1472861 bytes, checksum: 937810926b98a08677085a559d13aec9 (MD5) Previous issue date: 2015-09-15 / Não recebi financiamento / The usual models in repairable systems are minimal, perfect and imperfect repair, and, in the literature, the minimum repair model is the most explored. In repairable systems it is common that the same type of components are studied and in these cases is relevant to verify the heterogeneity between them. According to Vaupel et al. (1979), the standard methods for analysis of repairable systems data ignore the heterogeneity not observed and in some cases this should be considered. Such variability can be estimated from frailty models, characterized by using a random e ect. It is proposed that the minimum repair model with frailty in order to estimate the heterogeneity not observed between systems. For this model it was conducted a simulation study in order to analyze the frequentist properties of the estimation process. The application of a real data set showed the applicability of the proposed model, in which the estimation of the parameters were determined from maximum likelihood and Bayesian approaches. / Os modelos de sistemas reparáveis usuais são os de reparo mí nimo, perfeito e imperfeito, sendo que, na literatura, o modelo de reparo mí nimo e o mais explorado. Em sistemas reparáveis e comum que componentes do mesmo tipo sejam estudados e nestes casos é relevante verifi car a heterogeneidade entre eles. Segundo Vaupel et al. (1979), os métodos padrões em análise de dados de sistemas reparáveis ignoram a heterogeneidade não observada e em alguns casos esta deveria ser considerada. Tal variabilidade pode ser estimada a partir dos modelos de fragilidade, caracterizados pela utilização de um efeito aleat ório. Propõe-se o modelo de reparo mí nimo com fragilidade, a fi m de estimar a heterogeneidade não observada entre sistemas. Para este modelo foi realizado um estudo de simula ção com o objetivo de analisar as propriedades frequentistas do processo de estimação. A aplicação em um conjunto de dados reais mostrou a aplicabilidade do modelo proposto, em que a estima ção dos parâmetros foram determinadas a partir das abordagens de m áxima verossimilhan ça e Bayesiana.