862 resultados para gynaecological cancer screening
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Peer reviewed
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Peer reviewed
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Peer reviewed
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OBJECTIVE: To demonstrate the application of causal inference methods to observational data in the obstetrics and gynecology field, particularly causal modeling and semi-parametric estimation. BACKGROUND: Human immunodeficiency virus (HIV)-positive women are at increased risk for cervical cancer and its treatable precursors. Determining whether potential risk factors such as hormonal contraception are true causes is critical for informing public health strategies as longevity increases among HIV-positive women in developing countries. METHODS: We developed a causal model of the factors related to combined oral contraceptive (COC) use and cervical intraepithelial neoplasia 2 or greater (CIN2+) and modified the model to fit the observed data, drawn from women in a cervical cancer screening program at HIV clinics in Kenya. Assumptions required for substantiation of a causal relationship were assessed. We estimated the population-level association using semi-parametric methods: g-computation, inverse probability of treatment weighting, and targeted maximum likelihood estimation. RESULTS: We identified 2 plausible causal paths from COC use to CIN2+: via HPV infection and via increased disease progression. Study data enabled estimation of the latter only with strong assumptions of no unmeasured confounding. Of 2,519 women under 50 screened per protocol, 219 (8.7%) were diagnosed with CIN2+. Marginal modeling suggested a 2.9% (95% confidence interval 0.1%, 6.9%) increase in prevalence of CIN2+ if all women under 50 were exposed to COC; the significance of this association was sensitive to method of estimation and exposure misclassification. CONCLUSION: Use of causal modeling enabled clear representation of the causal relationship of interest and the assumptions required to estimate that relationship from the observed data. Semi-parametric estimation methods provided flexibility and reduced reliance on correct model form. Although selected results suggest an increased prevalence of CIN2+ associated with COC, evidence is insufficient to conclude causality. Priority areas for future studies to better satisfy causal criteria are identified.
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Improvements in diagnostic techniques and, above all, breast cancer screening campaigns - essential for early diagnosis - have enabled the objectives of conservative surgery to be pursued: disease control, no or low incidence of recurrences and an excellent esthetic result. However, to reach these objectives, it is essential to ensure a careful evaluation of the medical history of every patient, a detailed clinical examination and the correct interpretation of imaging. Particular attention should be paid to all factors influencing the choice of treatment and/or possible local recurrence: age, site, tumor volume, genetic predisposition, pregnancy, previous radiotherapy, pathological features, and surgical margins. The decision to undertake conservative treatment thus requires a multidisciplinary approach involving pathologists, surgeons and oncological radiologists, as well, of course, as the patient herself.
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This work describes preliminary results of a two-modality imaging system aimed at the early detection of breast cancer. The first technique is based on compounding conventional echographic images taken at regular angular intervals around the imaged breast. The other modality obtains tomographic images of propagation velocity using the same circular geometry. For this study, a low-cost prototype has been built. It is based on a pair of opposed 128-element, 3.2 MHz array transducers that are mechanically moved around tissue mimicking phantoms. Compounded images around 360 degrees provide improved resolution, clutter reduction, artifact suppression and reinforce the visualization of internal structures. However, refraction at the skin interface must be corrected for an accurate image compounding process. This is achieved by estimation of the interface geometry followed by computing the internal ray paths. On the other hand, sound velocity tomographic images from time of flight projections have been also obtained. Two reconstruction methods, Filtered Back Projection (FBP) and 2D Ordered Subset Expectation Maximization (2D OSEM), were used as a first attempt towards tomographic reconstruction. These methods yield useable images in short computational times that can be considered as initial estimates in subsequent more complex methods of ultrasound image reconstruction. These images may be effective to differentiate malignant and benign masses and are very promising for breast cancer screening. (C) 2015 The Authors. Published by Elsevier B.V.
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This paper seeks to identify the sources of value in a government health screening service. Consumers' use of such services for their won benefits demonstrates desirable behaviour and their continued use of these services indicates maintenance of the behaviour. There are also positive outcomes for society as the health of its members is improved overall through this behaviour. Individual-depth interview with 25 women who use breast cancer screening services provided by BreastScreen (BSQ) revealed five categories of sources of value. They are information sources, interaction sources, service, environment, and consumer participation. These findings provide valuable insights into the value construction of consumers and contribute towards our understanding of the value concept in social marketing.
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Customer perceived value is concerned with the experiences of consumers when using a service and is often referred to in the context of service provision or on the basis of service quality (Auh, et al., 2007; Chang, 2008; Jackson, 2007; Laukkanen, 2007; Padgett & Mulvey, 2007; Shamdasani, Mukherjee & Malhotra, 2008). Understanding customer perceived value has benefits for social marketing and allows scholars and practitioners alike to identify why consumers engage in positive social behaviours through the use of services. Understanding consumers’ use of wellness services in particular is important, because the use of wellness services demonstrates the fulfilment of social marketing aims; performing pro-active, positive social behaviours that are of benefit to the individual and to society (Andreasen, 1994). As consumers typically act out of self-interest (Rothschild, 1999), this research posits that a value proposition must be made to consumers in order to encourage behavioural change. Thus, this research seeks to identify how value is created for consumers of wellness services in social marketing. This results in the overall research question of this research: How is value created in social marketing wellness services? A traditional method towards understanding value has been the adoption of an economic approach, which considers the utility gained and where value is a direct outcome of a cost-benefit analysis (Payne & Holt, 1999). However, there has since been a shift towards the adoption of an experiential approach in understanding value. This experiential approach considers the consumption experience of the consumer which extends beyond the service exchange and includes pre- and post-consumption stages (Russell-Bennett, Previte & Zainuddin, 2009). As such, this research uses an experiential approach to identify the value that exists in social marketing wellness services. Four dimensions of value have been commonly conceptualised and identified in the commercial marketing literature; functional, emotional, social, and altruistic value (Holbrook, 1994; Sheth, Newman & Gross, 1991; Sweeney & Soutar, 2001). It is not known if these value dimensions also exist in social marketing. In addition, sources of value said to influence value dimensions have been conceptualised in the literature. Sources of value such as information, interaction, environment, service, customer co-creation, and social mandate have been conceptually identified both in the commercial and social marketing literature (Russell-Bennet, Previte & Zainuddin, 2009; Smith & Colgate, 2007). However, it is not clear which sources of value contribute to the creation of value for users of wellness services. Thus, this research seeks to explore these relationships. This research was conducted using a wellness service context, specifically breast cancer screening services. The primary target consumer of these services is women aged 50 to 69 years old (inclusive) who have never been diagnosed with breast cancer. It is recommended that women in this target group have a breast screen every 2 years in order to achieve the most effective medical outcomes from screening. A two-study mixed method approach was utilised. Study 1 was a qualitative exploratory study that analysed individual-depth interviews with 25 information-rich respondents. The interviews were transcribed verbatim and analysed using NVivo 8 software. The qualitative results provided evidence of the existence of the four value dimensions in social marketing. The results also allowed for the development of a typology of experiential value by synthesising current understanding of the value dimensions, with the activity aspects of experiential value identified by Holbrook (1994) and Mathwick, Malhotra and Rigdon (2001). The qualitative results also provided evidence for the existence of sources of value in social marketing, namely information, interaction, environment and consumer participation. In particular, a categorisation of sources of value was developed as a result of the findings from Study 1, which identify organisational, consumer, and third party sources of value. A proposed model of value co-creation and a set of hypotheses were developed based on the results of Study 1 for further testing in Study 2. Study 2 was a large-scale quantitative confirmatory study that sought to test the proposed model of value co-creation and the hypotheses developed. An online-survey was administered Australia-wide to women in the target audience. A response rate of 20.1% was achieved, resulting in a final sample of 797 useable responses after removing ineligible respondents. Reliability and validity analyses were conducted on the data, followed by Exploratory Factor Analysis (EFA) in PASW18, followed by Confirmatory Factor Analysis (CFA) in AMOS18. Following the preliminary analyses, the data was subject to Structural Equation Modelling (SEM) in AMOS18 to test the path relationships hypothesised in the proposed model of value creation. The SEM output revealed that all hypotheses were supported, with the exception of one relationship which was non-significant. In addition, post hoc tests revealed seven further significant non-hypothesised relationships in the model. The quantitative results show that organisational sources of value as well as consumer participation sources of value influence both functional and emotional dimensions of value. The experience of both functional and emotional value in wellness services leads to satisfaction with the experience, followed by behavioural intentions to perform the behaviour and use the service again. One of the significant non-hypothesised relationships revealed that emotional value leads to functional value in wellness services, providing further empirical evidence that emotional value features more prominently than functional value for users of wellness services. This research offers several contributions to theory and practice. Theoretically, this research addresses a gap in the literature by using social marketing theory to provide an alternative method of understanding individual behaviour in a domain that has been predominantly investigated in public health. This research also clarifies the concept of value and offers empirical evidence to show that value is a multi-dimensional construct with separate and distinct dimensions. Empirical evidence for a typology of experiential value, as well as a categorisation of sources of value is also provided. In its practical contributions, this research identifies a framework that is the value creation process and offers health services organisations a diagnostic tool to identify aspects of the service process that facilitate the value creation process.
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In maintaining quality of life, preventative health is an important area in which the performance of pro-social behaviours provides benefits to individuals who perform them as well as society. The establishment of the Preventative Health Taskforce in Australia demonstrates the significance of preventative health and aims to provide governments and health providers with evidence-based advice on preventative health issues (Preventative Health Taskforce, 2009). As preventative health behaviours are voluntary, for consumers to sustain this behaviour there needs to be a value proposition (Dann, 2008; Kotler and Lee, 2008). Customer value has been shown to influence repeat behaviour (McDougall and Levesque, 2000), word-of-mouth (Hartline and Jones, 1999), and attitudes (Dick and Basu, 2008). However to date there is little research that investigates the source of value for preventative health services. This qualitative study explores and identifies three categories of sources that influence four dimensions of value – functional, emotional, social and altruistic (Holbrook 2006). A conceptual model containing five propositions outlining these relationships is presented. This study provides evidence-based research that reveals sources of value that influence individuals’ decisions to perform pro-social behaviours in the long-term through their use of preventative health services. This research uses BreastScreen Queensland (BSQ), a cancer screening service, as the service context.
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BreastScreen Queensland (BSQ) is a government-based health service that provides free breast cancer screening services to eligible women using digital mammography technology.' In 2007, BSQ launched its first social marketing campaign' aimed at achieving a 30 per cent increase in women's programme participation by addressing the barriers to regular screening and by dispelling myths about breast cancer (Tornabene 2010). 'The Facts' mass media social marketing campaign used a credible spokesperson, Australian journalist]ana Wendt, to deliver the call to action' Don't make excuses. Make an appointment'.
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O câncer ganha cada vez mais destaque como problema de saúde pública. Desta forma, diversas estratégias somam-se com objetivo de reduzir a morbi-mortalidade associada a este conjunto de doenças. Para o pleno sucesso das políticas de controle, o profissional de saúde, em especial o médico, assume papel fundamental. Contudo, depara-se com a deficiência encontrada nos currículos das escolas médicas (EM), principalmente no que tange ao ensino de ações desenvolvidas dentro da atenção primária em saúde. No Brasil, diversos projetos genericamente denominados de Ligas Acadêmicas (LA) têm ganhado destaque como propostas para ensino, enquanto atividades extracurriculares, através da iniciativa discente. Esta dissertação tem como objetivos: (1) avaliar a capacitação de alunos de Medicina quanto a conhecimentos e práticas para prevenção, rastreamento e diagnóstico precoce das neoplasias mais frequentes no Brasil e (2) avaliar a repercussão e as propostas das LA como complementação de ensino. Foi realizada a adaptação transcultural de um questionário autopreenchível utilizado em estudos norte-americanos como instrumento para coleta de dados. Os dados foram obtidos de alunos do último ano de uma universidade pública no Rio de Janeiro. Dos 78 alunos elegíveis, 74 participaram do estudo. Destes, 87% consideram que o estudo de câncer no currículo é insuficiente. Apenas 4% souberam informar corretamente as neoplasias com protocolo de rastreamento recomendados no Brasil. Os resultados mostram que o treinamento em habilidades para o controle do câncer é fraco: quanto ao aconselhamento de pacientes, 30% receberam treinamento para orientar a cessação do tabagismo e um percentual ainda menor (15%) chegam ao final do curso sem terem sido treinados para avaliar a história nutricional dos pacientes. Em relação ao exame físico, quase 60% nunca foram treinados a realizar o exame clínico da pele, 50% terminam a graduação sem terem executado um preventivo ginecológico e quase 20% sem realizar o exame clínico das mamas. Já em relação a autopercepção, os alunos sentem-se muito mais preparados a aconselhar pacientes quanto a hábitos para prevenção do câncer. Outras variáveis estudadas (gênero, sistema de ingresso no vestibular e familiares/pessoas próximas com câncer) não afetaram o desempenho dos alunos nas dimensões avaliadas (treinamento, prática e autopercepção). Para avaliar o efeito graduação, foi utilizado um grupo controle formado por alunos do primeiro ano (n=77). Houve ganho significativo nas dimensões treinamento e prática quando comparamos os dois grupos e, numa proporção bem menor, na dimensão autopercepção. Para avaliação das LA, foi realizado um levantamento de todas as EM no Brasil que iniciaram suas atividades antes do ano de 2010 e, após relação nominal, foram identificadas aquelas com LA e com LA relacionada ao estudo do câncer. Contudo, o verdadeiro impacto destes projetos só pode ser entendido com uma análise qualitativa dos mesmos. Observa-se que, nas LA, os alunos são estimulados a desenvolver habilidades pouco abordadas nos currículos tradicionais, fundamentais para a formação profissional, como gestão, liderança, empreendedorismo, inovação, extensão universitária e construção da cidadania.
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O Estado do Rio de Janeiro possui indicadores de produção muito baixos na realização de exames de câncer de mama. Na tentativa de melhorar o acesso aos exames, principalmente em regiões com baixa densidade populacional onde a aquisição de mamógrafos não é custo-efetiva, o uso da mamografia móvel é uma alternativa para aumentar a execução de exames de rastreamento de câncer de mama. O objetivo desta pesquisa é a construção de um modelo computacional para definir a alocação de mamógrafos móveis. O Modelo considera as variáveis associadas com os custos e prazos, indicando quando, onde e por quanto tempo, as unidades móveis de mamografia devem permanecer em cada cidade. O modelo foi construído no software de modelagem e simulação Anylogic, usando técnicas de modelagem baseada em agentes. O principal resultado é determinar o percurso de cada veículo disponível, para oferecer a cobertura desejada em cada cidade. Todas as entradas são parametrizadas, permitindo simular diferentes cenários e fornecer informações importantes para o processo de tomada de decisão. O horizonte de tempo, número de mamógrafos (fixos e móveis), a cobertura desejada da população, a capacidade de produção de cada dispositivo, a adesão da população urbana e rural, entre outras variáveis, foram consideradas no modelo. Os dados da Região Serrana do Rio de Janeiro foram usados nas simulações, onde menos de metade das cidades possuem mamógrafos fixos. Com o modelo proposto foi possível determinar a distribuição de cada dispositivo físico e o número ótimo de unidades móveis de mamografia para oferecer cobertura à totalidade da população no ciclo de dois anos. O número de mamógrafos para oferecer cobertura de toda a população da região poderia ser reduzido pela metade com o modelo de alocação proposto neste trabalho. A utilização de mamografia móvel, em conjunto com a rede existente de mamógrafos fixos, procura maximizar a disponibilização de exames de testes de diagnóstico de câncer de mama no estado do Rio de Janeiro. O desenvolvimento de um modelo de roteamento que aperfeiçoa a cobertura de rastreio do câncer de mama é apresentado como um complemento importante na tentativa de melhorar o acesso à população residente em áreas urbanas e rurais dos municípios.
Implementação de um sistema de rastreio do cancro do colo do útero com base na detecção do vírus HPV
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
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Neoplastic tissue is typically highly vascularized, contains abnormal concentrations of extracellular proteins (e.g. collagen, proteoglycans) and has a high interstitial fluid pres- sure compared to most normal tissues. These changes result in an overall stiffening typical of most solid tumors. Elasticity Imaging (EI) is a technique which uses imaging systems to measure relative tissue deformation and thus noninvasively infer its mechanical stiffness. Stiffness is recovered from measured deformation by using an appropriate mathematical model and solving an inverse problem. The integration of EI with existing imaging modal- ities can improve their diagnostic and research capabilities. The aim of this work is to develop and evaluate techniques to image and quantify the mechanical properties of soft tissues in three dimensions (3D). To that end, this thesis presents and validates a method by which three dimensional ultrasound images can be used to image and quantify the shear modulus distribution of tissue mimicking phantoms. This work is presented to motivate and justify the use of this elasticity imaging technique in a clinical breast cancer screening study. The imaging methodologies discussed are intended to improve the specificity of mammography practices in general. During the development of these techniques, several issues concerning the accuracy and uniqueness of the result were elucidated. Two new algorithms for 3D EI are designed and characterized in this thesis. The first provides three dimensional motion estimates from ultrasound images of the deforming ma- terial. The novel features include finite element interpolation of the displacement field, inclusion of prior information and the ability to enforce physical constraints. The roles of regularization, mesh resolution and an incompressibility constraint on the accuracy of the measured deformation is quantified. The estimated signal to noise ratio of the measured displacement fields are approximately 1800, 21 and 41 for the axial, lateral and eleva- tional components, respectively. The second algorithm recovers the shear elastic modulus distribution of the deforming material by efficiently solving the three dimensional inverse problem as an optimization problem. This method utilizes finite element interpolations, the adjoint method to evaluate the gradient and a quasi-Newton BFGS method for optimiza- tion. Its novel features include the use of the adjoint method and TVD regularization with piece-wise constant interpolation. A source of non-uniqueness in this inverse problem is identified theoretically, demonstrated computationally, explained physically and overcome practically. Both algorithms were test on ultrasound data of independently characterized tissue mimicking phantoms. The recovered elastic modulus was in all cases within 35% of the reference elastic contrast. Finally, the preliminary application of these techniques to tomosynthesis images showed the feasiblity of imaging an elastic inclusion.
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Ovarian cancer is a leading cause of gynaecological cancer-related morbidity and mortality. There has been increasing interest in the potential utility of anti-human epidermal growth factor receptor 2 (anti-HER2) agents in the treatment of this disease, with the attendant need to identify suitable predictive biomarkers of response to treatment.