36 research outputs found

    Progression of the first stage of spontaneous labour: A prospective cohort study in two sub-Saharan African countries.

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    BACKGROUND: Escalation in the global rates of labour interventions, particularly cesarean section and oxytocin augmentation, has renewed interest in a better understanding of natural labour progression. Methodological advancements in statistical and computational techniques addressing the limitations of pioneer studies have led to novel findings and triggered a re-evaluation of current labour practices. As part of the World Health Organization's Better Outcomes in Labour Difficulty (BOLD) project, which aimed to develop a new labour monitoring-to-action tool, we examined the patterns of labour progression as depicted by cervical dilatation over time in a cohort of women in Nigeria and Uganda who gave birth vaginally following a spontaneous labour onset. METHODS AND FINDINGS: This was a prospective, multicentre, cohort study of 5,606 women with singleton, vertex, term gestation who presented at ≤ 6 cm of cervical dilatation following a spontaneous labour onset that resulted in a vaginal birth with no adverse birth outcomes in 13 hospitals across Nigeria and Uganda. We independently applied survival analysis and multistate Markov models to estimate the duration of labour centimetre by centimetre until 10 cm and the cumulative duration of labour from the cervical dilatation at admission through 10 cm. Multistate Markov and nonlinear mixed models were separately used to construct average labour curves. All analyses were conducted according to three parity groups: parity = 0 (n = 2,166), parity = 1 (n = 1,488), and parity = 2+ (n = 1,952). We performed sensitivity analyses to assess the impact of oxytocin augmentation on labour progression by re-examining the progression patterns after excluding women with augmented labours. Labour was augmented with oxytocin in 40% of nulliparous and 28% of multiparous women. The median time to advance by 1 cm exceeded 1 hour until 5 cm was reached in both nulliparous and multiparous women. Based on a 95th percentile threshold, nulliparous women may take up to 7 hours to progress from 4 to 5 cm and over 3 hours to progress from 5 to 6 cm. Median cumulative duration of labour indicates that nulliparous women admitted at 4 cm, 5 cm, and 6 cm reached 10 cm within an expected time frame if the dilatation rate was ≥ 1 cm/hour, but their corresponding 95th percentiles show that labour could last up to 14, 11, and 9 hours, respectively. Substantial differences exist between actual plots of labour progression of individual women and the 'average labour curves' derived from study population-level data. Exclusion of women with augmented labours from the study population resulted in slightly faster labour progression patterns. CONCLUSIONS: Cervical dilatation during labour in the slowest-yet-normal women can progress more slowly than the widely accepted benchmark of 1 cm/hour, irrespective of parity. Interventions to expedite labour to conform to a cervical dilatation threshold of 1 cm/hour may be inappropriate, especially when applied before 5 cm in nulliparous and multiparous women. Averaged labour curves may not truly reflect the variability associated with labour progression, and their use for decision-making in labour management should be de-emphasized

    Exponentiated Modified Weibull model for Long-Term survivors applied on breast cancer survival

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    O câncer de mama é a neoplasia mundialmente mais incidente em mulheres, representando a causa mais frequente de morte feminina por câncer, excetuando-se os tumores de pele não melanoma. O conhecimento da dinâmica de óbitos ao logo do tempo em pacientes com tal neoplasia é de grande importância para auxílio na definição de tratamentos e de políticas de prevenção. Modelos de risco que contemplem parâmetros com referência a situações de longa duração e diferentes funções de risco podem ser úteis nesse contexto. O objetivo desta dissertação é investigar as propriedades de um particular modelo, o modelo Weibull Modificado Exponenciado de Longa Duração (WMELD), para aplicação na avaliação de risco e sobrevida de mulheres diagnosticadas com câncer de mama atendidas no Hospital das Clínicas de Ribeirão Preto, São Paulo. As propriedades avaliadas neste estudo consideraram métodos de estimação pontual de Máxima Verossimilhança e estimação intervalar via teoria assintótica, reamostragem bootstrap e verossimilhança perlada. Critérios de seleção de modelos foram considerados: Teste de Razão de Verossimilhanças (TRV), critério de Akaike (AIC) e critério de Informação de Bayes (BIC), bem como métodos gráficos para avaliar a qualidade do ajuste do modelo: gráfico TTT na presença de censuras com intervalo de confiança bootstrap paramétrico. Foram realizados estudos de simulação de Monte Carlo em diferentes cenários do modelo WMELD, considerando Vício, Erro Quadrático Médio (EQM) e Custo dos estimadores pontuais, Probabilidade de Cobertura e Amplitude Média dos intervalos de confiança. Em relação ao estudo das propriedades do modelo, as estimativas pontuais de máxima verossimilhança apresentaram vício e EQM baixos e mais próximos de zero quanto maior o tamanho amostral e menor a proporção de pacientes imunes. Os intervalos construídos com base em reamostragem bootstrap mostraram-se mais adequados em relação à probabilidade de cobertura e amplitude média, com vantagem para o bootstrap paramétrico. AIC e TRV alcançaram poder discriminativo superior ao BIC, porém os três métodos apresentam-se defasados para pequenos tamanhos amostrais e valores dos parâmetros próximos do valor de nulidade. Os métodos de inferência com melhor desempenho nesse estudo foram considerados para avaliar os fatores associados ao risco e sobrevida de pacientes com câncer de mama atendidas no HCFMRP. Com o ajuste do modelo WMELD, mostraram-se associados à sobrevida os fatores: Estadiamento, Faixa Etária e Quantidade de tratamentos. A sobrevida em oito anos ou mais foi maior quanto menor o estadiamento e os óbitos ocorreram de forma mais acelerada ao longo do tempo em estadiamentos avançados. Pacientes com menos de 35 anos de idade nos estadiamentos II e III e com mais de 75 anos no estadiamento III têm menor sobrevida do que as pacientes com 35 a 75 anos. Pacientes que realizaram menos tratamentos nos estadiamentos III ou IV vão a óbito mais rapidamente do que pacientes que zeram mais tratamentos, porém a sobrevida após oito ou mais anos é igual nos dois grupos. Adicionalmente, e fundamental no contexto da clínica médica, o modelo WMELD apresenta interpretações relevantes em relação a seus parâmetros na dinâmica do processo de ocorrência de óbitos ao longo do tempo. Verificamos que os parâmetros , e p levam informações sobre o tempo de vida, já os parâmetros, e descrevem o comportamento do risco de óbito.Breast cancer is the world\'s most common cancer in women, representing the most frequent cause of female death from cancer, except for non-melanoma skin tumors. Knowledge of the death dynamics over time in patients with such cancer is very important to support definition of treatments and prevention policies. Hazard models that include parameters with reference to long-term situations and dierent hazard functions can be useful in this context. This paper aims to investigate the properties of a particular model, Exponentiated Modified Weibull Model for long-term survivors (EMWLT), for use in risk of death and survival assessment of women diagnosed with breast cancer and treated at Hospital das Clínicas de Ribeirão Preto (HCFMRP), São Paulo. The properties evaluated in this study considered point estimation methods of Maximum Likelihood and interval estimation through asymptotic theory, bootstrap resampling and profile likelihood. Model selection criteria were considered: Likelihood Ratio Test (LRT), Akaike Criterion (AIC) and Bayesian Information Criterion (BIC), as well graphical methods to assess the quality of the model fit: TTT plot in the presence of censorship with an parametric bootstrap confidence interval. Monte Carlo simulation studies were performed in diferent model\'s scenarios considering Bias, Mean Square Error (MSE) and Cost of point estimators, Coverage Probability and Average Size of confidence intervals. Regarding the study of model properties, the point estimates of maximum likelihood showed lower and closer to zero bias and MSE the larger the sample size and the lower the proportion of immune patients. The intervals constructed based on bootstrap resampling seemed more appropriated in relation to the coverage probability and average size, advantageously the parametric bootstrap. AIC and LRT reached a higher discriminative power than BIC; however, all of these three methods seemed lagged for small sample sizes and close to null values of parameters. The inference methods with better performance in this study were considered to evaluate the factors associated with risk of death and survival in patients with breast cancer treated at HCFMRP. By adjusting the EMWLT model, the following were associated to survival: Staging, Age Group and Number of treatments. The survival of eight years or more was higher as the lower the staging was; and the deaths occurred more rapidly over time in advanced staging. Patients under 35 years old in stages II and III and older than 75 years in staging III had lower survival than patients aged 35 to 75 years. Patients who underwent fewer treatments in staging III or IV die earlier than patients who underwent more treatments, but survival after eight years or more is equal in both groups. In addition, the EMWLT model showed to be fundamental in clinical medicine presenting relevant interpretations regarding its parameters in the dynamics of the process of occurrence of deaths over time. We verified that the parameters , and p have information about the lifetime, on the other hand the parameters, and describe the risk of death behavior

    História reprodutiva e sexual de mulheres tratadas de câncer de mama Reproductive and sexual history of women treated of breast cancer

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    OBJETIVO: Compreender a vida sexual e reprodutiva de mulheres tratadas de câncer de mama. MÉTODOS: Foram entrevistadas 139 mulheres com diagnóstico há pelo menos seis meses, selecionadas aleatoriamente em um serviço de reabilitação. As entrevistas foram feitas entre 2006 e 2010. Todas eram usuárias do SUS, pacientes de um hospital regional e moradoras da região DRS XIII-Ribeirão Preto, Estado de São Paulo. As entrevistadas foram visitadas em seu domicílio onde foi aplicado um questionário face a face que abordava questões relativas às características sociodemográficas, da doença e da vida reprodutiva e sexual, para esta última aplicou-se o instrumento Índice de Função Sexual Feminina (IFSF). A análise estatística incluiu o teste do χ², o teste exato de Fisher e o teste t de Student, análise multivariada por regressão logística e análise fatorial e alfa de Cronbach. RESULTADOS: A maioria teve entre 2 e 3 filhos e 80% utilizaram algum método anticoncepcional. Cerca de metade das mulheres tiveram relação sexual no último mês, 45,3% interromperam as relações sexuais durante o tratamento e 25,9% não interromperam. Houve relato de diminuição da frequência sexual, embora metade das entrevistadas tenha retomado a vida sexual nos primeiros seis meses após o tratamento. Pouco mais de metade apresentou insatisfação sexual. Encontrou-se vida sexual ativa associada à idade menor que 40 anos e a ter parceiro. Não foi encontrada associação entre vida sexual ativa e ao diagnóstico e tipos de tratamento. CONCLUSÃO: A atividade sexual de mulheres tratadas para câncer de mama não está associada aos tratamentos, mas à idade e à oportunidade de ter sexo.PURPOSE: To understand the reproductive and sexual life of women treated for breast cancer. METHODS: A total of 139 women with a diagnosis made at least 6 months ago were interviewed after being randomly selected in a rehabilitation service. The interviews were carried out between 2006 and 2010. The inclusion criteria were: to have used a rehabilitation service between 2006 and 2010, to be a Unified Health System user, to have been a patient at a regional hospital and to be resident in the area of DRS XIII-Ribeirão Preto, state of São Paulo. The interviewees were visited at home where a face to face questionnaire regarding sociodemographic features and questions about the disease and reproductive and sexual life was administered. For the last one, the Female Sexual Function Index instrument was used. Data were analyzed statistically by the χ² test, Fisher exact test, Student's t test, multivariate analysis by logistic regression, factorial analysis and the Cronbach's alpha. RESULTS: Most patients had between 2 to 3 children and 80% used some contraceptive. About half of them had had sexual intercourse in the last month, 45.3% had interrupted sexual intercourse during treatment and 25.9% did not. There were reports of decreasing sexual activity, although half of the interviewees had re-started sexual life during the first six months after treatment. About half presented sexual dissatisfaction. An active sexual life is associated with being younger than 40 years of age and to have a partner. No association was found between active sexual life and diagnosis and types of treatment. CONCLUSION: Sexual activity of women treated for breast cancer is not associated with the treatments, but with age and with the opportunity of having sex

    Plasma rico em plaquetas para reparação de falhas ósseas em cães

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    As plaquetas chegam rapidamente ao local da ferida e liberam múltiplos fatores de crescimento (FC) e citocinas que contribuem para a reparação óssea e aumentam a vascularização local. O Plasma Rico em Plaquetas (PRP) concentra as plaquetas e os FC liberados por elas, aceleram a formação óssea e melhora a qualidade do trabeculado. Este trabalho apresenta um protocolo para confecção de PRP e demonstra alguns aspectos da sua utilização na reparação óssea de cães. O protocolo foi desenvolvido a partir de sangue coletado por punção jugular em três cães adultos, pesando em média 20kg. Para avaliação da aplicação clínica e dos aspectos da reparação óssea, foram criadas duas falhas mediais no terço proximal de cada tíbia. Assim, a falha 1 não foi preenchida, constituindo o controle, a falha 2 foi preenchida com 3mg de enxerto ósseo autógeno da crista da tíbia, a falha 3 com gel de plaquetas (PRP) e falha a número 4 com a associação PRP e 3mg de enxerto ósseo autógeno. O protocolo laboratorial proposto mostrou-se de fácil execução e de baixo custo e possibilitou a concentração adequada de plaquetas no PRP final, cujo número foi dependente da contagem inicial no sangue total de cada animal. A comparação da radiopacidade na região da falha, em todos os tratamentos, e ao longo do tempo demonstrou que o PRP associado ao enxerto determinou maior precocidade e uniformidade de radiopacidade, quando comparado à falha preenchida pelo PRP e ao enxerto usados isoladamente, e sendo que ambos determinam melhores resultados de preenchimento que a falha mantida sem tratamento.The platelets arrive quickly at the injury site and release several growth factors (GF) and citokines that contribute to bone repair and increasing local vascularization. The Platelet-rich Plasma (PRP) concentrates the platelets and their growth factors, increasing the rate of bone formation and better quality of trabecular bone. This research presents a protocol to PRP formulation and demonstrates some aspects about the use in canine bone repair. In this protocol blood was obtained from the jugular ven of tree adult dogs with medium weight of 20kg to produce PRP. Two defects in the medial aspect of proximal third of the tibia were surgically created to evaluate the clinical and radiographic aspect of PRP. The control defect wasn’t treated.The defect 2 was filled with 3 mg of autogenous bone graft from the tibia crest. The defect 3 was filled with PRP alone and the number 4 with PRP in the combination with 3mg autogenous bone graft. The proposed laboratory protocol demonstrated to be easy to execute at low cost. Further, it was adequate to concentrate platelets in final PRP, whose number was dependent on the blood from each dog. Comparing the defect regions, was concluded that the association of PRP and bone graft showed greater precocity and uniform radiopacity than the PRP or bone graft isolated, although both determine better results than the defect without treatment

    Supplemental material for On the comparison of risk of death according to different stages of breast cancer via the long-term exponentiated Weibull hazard model

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    <p>Supplemental material for On the comparison of risk of death according to different stages of breast cancer via the long-term exponentiated Weibull hazard model by Hayala Cristina Cavenague de Souza, Gleici da Silva Castro Perdoná, Francisco Louzada and Fernanda Maris Peria in Statistical Methods in Medical Research</p
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