Finite Mixture Models based on Scale Mixtures of Skew-Normal distributions applied to serological data

Serological data can be described as a mixture of distributions, with each mixture component representing a serological population (e.g. seronegative and seropositive population). In seroepidemiological studies of infectious diseases, mixture models with Normal distribution are mostly used, which implies that the components that make up the mixture are approximately symmetric. However, it has been observed that, especially in seropositive populations, it is possible to observe skewness to the left, leading to the violation of the assumption of normality underlying the data. Thus, and in order to capture the possible skewness in serological data, the family of Scale Mixtures of Skew-Normal (SMSN) distributions is used, of which the Skew-Normal distribution and the Skew-t distribution are particular cases. In the case of the Skew-t distribution, being a heavy-tailed distribution, it allows capturing the possible existence of outliers. In addition to the models used to describe the behavior of the serological data, the issue of estimating the cutoff point for classifying an individual as seropositive is explored. In this sense, two perspectives on the problem are presented: one in which the true state of the disease is unknown; another in which this state is known a priori. The generalization of the use of a cutoff point without statistical methodology to support the estimation of this point may have consequences in the seroprevalence of a population, that is, in the proportion of seropositive individuals. Thus, three methods based on mixture models are proposed in this work for estimating the cutoff point when the true infection status is unknown

Spiritual well-being and religious commitment of cancer patients under chemotherapy

info:eu-repo/semantics/publishedVersio

Modelos de regressão para identificação de marcadores preditivos de asma na descendência de mulheres com atopia

Trabalho de projecto de mestrado, Bioestatística, Universidade de Lisboa, Faculdade de Ciências, 2016A atopia pode definir-se como sendo a tendência pessoal e/ou familiar para a produção de Imunoglobulina E (IgE) contra alergénios ambientais, traduzindo-se por eczema atópico, rinite alérgica e asma alérgica cujas manifestações se iniciam, normalmente, durante a infância e a adolescência. A possibilidade de identificar marcadores de risco para o desenvolvimento de atopia, precocemente, poderá ser o primeiro passo para o desenvolvimento de estratégias de prevenção para os indivíduos em risco. Assim, inicialmente, com este trabalho pretendeu-se identificar diferenças no perfil imunológico de mulheres grávidas com e sem atopia. Posteriormente, foi estudada a possível relação entre as diferenças encontradas nos parâmetros avaliados e o desenvolvimento de atopia na descendência das mulheres grávidas atópicas. Pretendeu-se, assim, não só reconhecer de que forma se relacionam entre si as variações nas diferentes populações celulares avaliadas, mas também se as suas variações de alguma forma se encontravam associadas com o desenvolvimento de atopia nas crianças. Confirmando-se a sua existência, esta relação entre parâmetros imunes maternos e o desenvolvimento de atopia, poderá potenciar a utilização futura destes parâmetros como marcadores preditivos para o desenvolvimento de atopia. De acordo com os objetivos definidos, procedeu-se à construção de modelos de regressão logística, considerando como covariáveis os marcadores de risco anteriormente identificados, bem como outras variáveis relevantes. A variável resposta consistiu na presença/ausência de atopia na descendência. Pela aplicação de modelos de regressão logística, verificou-se a influência dos linfócitos B de transição como fator de risco para a atopia na descendência de mulheres grávidas atópicas.Atopy can be defined as the personal and/or familiar tendency to production of immunoglobulin E (IgE) against environmental allergens, resulting in atopic eczema, allergic rhinitis and allergic asthma whose manifestations begin, usually during childhood and adolescence. The possibility to identify risk factors for the development of atopy, early in life, could be the first step for the development of prevention strategies for individuals at risk. So, initially, this work aimed to identify differences in the immune profile of pregnant women with and without atopy. Subsequently, the possible relationship between the differences in the evaluated parameters and the development of atopy in the offspring of atopic pregnant women was studied. Thus, the aim was not only to recognize how the variation in the different evaluated cell populations were related, but also if their variations were somehow associated with the development of atopy in children. Confirming its existence, the relationship between maternal immune parameters and the development of atopy, may enhance the future use of these parameters as predictive markers for the development of atopy. According to the objectives set, the construction of regression models were made considering as covariates the previously identified risk markers, as well as other relevant variables. The dependent variable was the presence/absence of atopy in the offspring. Using logistic regression models, transitional B cells were identified as a factor risk for atopy event in the progeny of atopic pregnant women

Doentes oncológicos críticos admitidos em Unidade de Cuidados Intensivos - preditores de mortalidade

O objectivo principal deste estudo consiste em identificar potenciais factores preditivos de mortalidade nos doentes oncológicos críticos admitidos em UCI. Pretende-se ainda avaliar a mortalidade na UCI, hospitalar e 30-dias após a alta; os índices de gravidade à admissão; as causas de admissão; as características da doença oncológica e o subgrupo de doentes admitidos por causa médica.info:eu-repo/semantics/publishedVersio

Validation of the Spiritual Distress Scale in Portuguese cancer patients undergoing chemotherapy: a methodological study

Spiritual distress may ascend from unmet spiritual needs. The use of instruments to measure spiritual distress seems to facilitate the approach to spirituality, such as the Spiritual Distress Scale (SDS) that has been used worldwide. No instrument to assess spiritual distress in cancer patients is currently available in Portugal. This study aims to conduct the translation, adaptation and validation of the SDS in Portuguese cancer patients undergoing chemotherapy. Methodological study based on Sousa and Rojjanasrirat (2011), a seven-step approach, started with the linguistic translation to the psychometric tests. The main participants (55.4%) were older than 60 years; about 64.7% were females, married (68.0%), and 86.7% were Catholic. Moderate spiritual distress was experienced by 49.3% of the participants. Linguistic and conceptual equivalences were obtained. The SDS European Portuguese version has an overall Cronbach’s alpha of 0.91, and the subscales were as follows: “relationship with self” (0.92), “relationship with others” (0.63), “relationship with God” (0.64) and “facing death” (0.85). Four factors emerged after Varimax rotation. Overall, these results indicate that the SDS European Portuguese version has good psychometric characteristics and can used in assessing spiritual distress in cancer patients.info:eu-repo/semantics/publishedVersio

Análise Automática vs Análise Manual no diagnóstico da síndrome de apneia obstrutiva do sono

A Síndrome Apneia Obstrutiva do Sono (SAOS) caracteriza-se por períodos de diminuição ou ausência total do fluxo respiratório resultantes do colapso da via aérea superior durante o sono, que podem estar associados a fragmentação deste e alteração das trocas gasosas. Estas alterações do sono são avaliadas através da realização de exames, polissonografia ou estudo cardiorrespiratório e a sua presença permite fazer o diagnóstico de SAOS. A gravidade da SAOS é determinada através do índice de apneia-hipopneia (IAH), sendo considerada de gravidade ligeira entre 5 e 14,9; moderada de 15 a 29,9; e grave igual ou superior a 30 eventos respiratórios/hora. Para um diagnóstico válido é importante uma correta análise dos parâmetros respiratórios. Com o presente estudo pretende-se realizar a comparação entre a análise automática e a análise manual em exames de sono cardiorrespiratórios no que respeita ao diagnóstico da SAOS, no sentido verificar a existência de “misdiagnosis” quando utilizada a análise automática e a sua expressividade em termos de gravidade. Foram avaliados 2980 exames de doentes com suspeita de SAOS, realizados entre 2011 e 2019 sendo utilizado o software de análise Remlogic e seguidas as diretrizes da American Academy of Sleep Medicine mais atuais. No resultado do IAH automático versus manual verifica-se que com base na análise automática, 1240 estudos foram negativospara diagnóstico de SAOS, dos quais comparados com a análise manual 238 (19,2%) mantinham o diagnóstico negativo; 575 (46,4%) passam para SAOS de grau ligeiro; 269 (21,7%) passam para SAOS de grau moderado e 158 (12,7%) passam para SAOS de grau grave, existindo 80,8% de “misdiagnosis”. De acordo com os resultados obtidos, conclui-se que a análise automática destes exames pode levar a um incorreto diagnóstico da SAOS assim como da sua gravidade, sendo importante que o diagnóstico desta patologia seja baseado numa análise manual de todos os parâmetros.info:eu-repo/semantics/publishedVersio

Pancreatic cancer associated- cachexia: Role of the Modified Glasgow Prognostic Score in outcome prediction

Cancer-associated-cachexia (CAC) is a ubiquitous characteristic of pancreatic cancer (PC) and 1/3 of patients die from its complications. Systemic inflammation is key in CAC and the modified Glasgow Prognostic Score (mGPS) is a reliable inflammation-based prognostic tool. We aimed to evaluate the prognostic value of consensus-based cachexia classification and mGPS, their agreement and to analyze relevant clinical predictors of cachexia. This unicentric, retrospective, cohort study included patients with advanced PC treated over a 5-year period. Cachexia was classified according to weight loss, body mass index and mGPS. Fisher’s test was used to test correlation between classifications and logistic regression models were performed to test their association with other variables. Survival was analyzed with cox regression and Kaplan-Meier curves. 88 eligible patients (mean age 72, 56% female) were reviewed. At baseline, cachectic patients (CP) (77%), when compared with pre-CP, had worse performance status (p=0.016), more NLR>3,5 (p3.5 was a significant predictor of both cachexia (p<0.001) and positive mGPS (p<0.01). Median overall survival (OS) for pre-CP was 19.1 months vs. 4.9 months in the CP (HR 1.94 95% CI 1.10-3.43 p=0.02). A positive mGPS at baseline was an independent predictor of worst OS (HR 2.73, 95% CI 1.12- 6.66, p=0.027). CAC leads to worst survival and a better understanding of this syndrome in PC may improve outcomes for these patients. Our study suggests a baseline predominant fat-only loss phenotype, that patients with positive mGPS are at higher risk of worst outcomes and that NLR is a potential predictor of CAC. A prompt identification of prognostic markers may lead to a better standardized management of CAC

Endoscopy Timing in Patients with Acute Upper Gastrointestinal Bleeding

Background/Aims The role of very early (≤12 hours) endoscopy in nonvariceal upper gastrointestinal bleeding is controversial. We aimed to compare results of very early and early (12–24 hours) endoscopy in patients with upper gastrointestinal bleeding demonstrating low-risk versus high-risk features and nonvariceal versus variceal bleeding. Methods This retrospective study included patients with nonvariceal and variceal upper gastrointestinal bleeding. The primary outcome was a composite of inpatient death, rebleeding, or need for surgery or intensive care unit admission. Endoscopy timing was defined as very early and early. We performed the analysis in two subgroups: (1) high-risk vs. low-risk patients and (2) variceal vs. nonvariceal bleeding. Results A total of 102 patients were included, of whom 59.8% underwent urgent endoscopy. Patients who underwent very early endoscopy received endoscopic therapy more frequently (p=0.001), but there was no improvement in other clinical outcomes. Furthermore, patients at low risk and with nonvariceal bleeding who underwent very early endoscopy had a higher risk of the composite outcome. Conclusions Very early endoscopy does not seem to be associated with improved clinical outcomes and may lead to poorer outcomes in specific populations with upper gastrointestinal bleeding. The actual benefit of very early endoscopy remains controversial and should be further clarified

Attitudes and behaviors towards vaccination in Portuguese nursing students

Knowing the attitudes and behaviors of nursing students in relation to vaccination is important because they will soon be determinant for the health literacy of the population. Vaccination remains the most effective response in the fight against communicable diseases, including COVID-19 and influenza. The objective of this study is to analyze the attitudes and behaviors of Portuguese nursing students with regard to vaccination. A cross-sectional study was carried out, with data collection from nursing students at a university in Lisbon, Portugal. A sample of 216 nursing students was obtained, representing 67.1% of the students enrolled in this university. What stands out from the results of the questionnaire “Attitudes and Behaviors in Relation to Vaccination among Students of Health Sciences” is that for the majority of students the answers were positive; in addition, 84.7% had a completed vaccination schedule for COVID-19. Being a nursing student, being in the final years of the course and being a woman are the factors that most influence the positive attitude of the students. The results obtained are motivating, because these students will be the future health professionals most likely to integrate health promotion programs through vaccination.info:eu-repo/semantics/publishedVersio

Pancreatic cancer associated- cachexia: Role of the Modified Glasgow Prognostic Score in outcome prediction

Cancer-associated-cachexia (CAC) is a ubiquitous characteristic of pancreatic cancer (PC) and 1/3 of patients die from its complications. Systemic inflammation is key in CAC and the modified Glasgow Prognostic Score (mGPS) is a reliable inflammation-based prognostic tool. We aimed to evaluate the prognostic value of consensus-based cachexia classification and mGPS, their agreement and to analyze relevant clinical predictors of cachexia. This unicentric, retrospective, cohort study included patients with advanced PC treated over a 5-year period. Cachexia was classified according to weight loss, body mass index and mGPS. Fisher’s test was used to test correlation between classifications and logistic regression models were performed to test their association with other variables. Survival was analyzed with cox regression and Kaplan-Meier curves. 88 eligible patients (mean age 72, 56% female) were reviewed. At baseline, cachectic patients (CP) (77%), when compared with pre-CP, had worse performance status (p=0.016), more NLR>3,5 (p3.5 was a significant predictor of both cachexia (p<0.001) and positive mGPS (p<0.01). Median overall survival (OS) for pre-CP was 19.1 months vs. 4.9 months in the CP (HR 1.94 95% CI 1.10-3.43 p=0.02). A positive mGPS at baseline was an independent predictor of worst OS (HR 2.73, 95% CI 1.12- 6.66, p=0.027). CAC leads to worst survival and a better understanding of this syndrome in PC may improve outcomes for these patients. Our study suggests a baseline predominant fat-only loss phenotype, that patients with positive mGPS are at higher risk of worst outcomes and that NLR is a potential predictor of CAC. A prompt identification of prognostic markers may lead to a better standardized management of CAC