Using a Bayesian change-point statistical model with autoregressive terms to study the monthly number of dispensed asthma medications by public health services

In this paper, it is proposed a Bayesian analysis of a time series in the presence of a random change-point and autoregressive terms. The development of this model was motivated by a data set related to the monthly number of asthma medications dispensed by the public health services of Ribeirão Preto, Southeast Brazil, from 1999 to 2011. A pronounced increase trend has been observed from 1999 to a specific change-point, with a posterior decrease until the end of the series. In order to obtain estimates for the parameters of interest, a Bayesian Markov Chain Monte Carlo (MCMC) simulation procedure using the Gibbs sampler algorithm was developed. The Bayesian model with autoregressive terms of order 1 fits well to the data, allowing to estimate the change-point at July 2007, and probably reflecting the results of the new health policies and previously adopted programs directed toward patients with asthma. The results imply that the present model is useful to analyse the monthly number of dispensed asthma medications and it can be used to describe a broad range of epidemiological time series data where a change-point is present.Peer Reviewe

Using a Bayesian change-point statistical model with autoregressive terms to study the monthly number of dispensed asthma medications by public health services

In this paper, it is proposed a Bayesian analysis of a time series in the presence of a random change-point and autoregressive terms. The development of this model was motivated by a data set related to the monthly number of asthma medications dispensed by the public health services of Ribeirão Preto, Southeast Brazil, from 1999 to 2011. A pronounced increase trend has been observed from 1999 to a specific change-point, with a posterior decrease until the end of the series. In order to obtain estimates for the parameters of interest, a Bayesian Markov Chain Monte Carlo (MCMC) simulation procedure using the Gibbs sampler algorithm was developed. The Bayesian model with autoregressive terms of order 1 fits well to the data, allowing to estimate the change-point at July 2007, and probably reflecting the results of the new health policies and previously adopted programs directed toward patients with asthma. The results imply that the present model is useful to analyse the monthly number of dispensed asthma medications and it can be used to describe a broad range of epidemiological time series data where a change-point is present

Avaliação da qualidade de vida em pacientes com anemia falciforme: diferenças entre adultos e crianças

Sickle cell anemia is one of the most common inherited diseases worldwide. It is believed that quality of life (QoL) of the sickle cell patient is very low and that in its general socio-economic conditions and cultural well indicate lack in several aspects. The objective this study was to describe and analyze the QoL of patients with sickle cell anemia In a Hematology clinic of a teaching hospital in Southeastern Brazil. This is a cross-sectional study with application of the WHOQOL-BREF instrument, on the four domains, in adults (group 1) and children (group 2) carriers of sickle cell anemia. In the calculation of differences between proportions was employed the chi-square test. To check for differences between the means was used the Student t test for independent samples. For analysis of association between variables, we used prevalence ratio (PR) with its confidence interval at 95% (CI 95%), as estimates of magnitude. A significance level of 5% was considered in all analysis. In group 1 were selected 27 patients (54%) with mean age of 27.2 years old and 58.3% female, while in group 2 were 23 children(46%) whose mean age was 8.7 years old, with 57.1% of the sample consisted of male patients. QoL was higher among patients of the group 2 in physical and environmental domains (p <0.05). The population studied presented a favorable QoL, with means above 11 in all domains. Patients aged ? 13 years old had better QoL compared to > 13 years, possibly indicating better physical functioning and less psychological conflicts.A anemia falciforme é uma das doenças hereditárias mais comuns em todo o mundo. Acredita-se que a qualidade de vida (QV) do paciente com a doença falciforme é muito baixa e que suas condições socioeconômicas e culturais indicam deficiências em vários aspectos. O objetivo deste estudo foi descrever e analisar a QV dos pacientes com anemia falciforme assistidos em um ambulatório de hematologia de um hospital de ensino no sudeste do Brasil. Este é um estudo transversal com aplicação do instrumento WHOQOL-BREF em adultos (grupo 1) e crianças (grupo 2) com anemia falciforme. No cálculo de diferenças entre proporções foi utilizado o teste do qui-quadrado. Para verificar diferenças entre as médias foi utilizado o teste t de Student para amostras independentes. Para análise da associação entre as variáveis, foi empregada a razão de prevalência (RP) com seu intervalo de confiança a 95% (IC95%), como estimadores de magnitude. Considerou-se um nível de significância de 5% em todas as análises. No grupo 1 foram selecionados 27 pacientes (54%) com média de idade de 27,2 anos, sendo 58,3% do sexo feminino, enquanto que no grupo 2 foram 23 crianças (46%), cuja média de idade foi de 8,7 anos, com 57,1% da amostra do sexo masculino. A QV foi maior entre os pacientes do grupo 2 nos domínios físicos e ambiental (p<0,05). A população estudada apresentou uma QV favorável, com valores médios acima de 11 em todos os domínios. Pacientes com idade ? 13 anos apresentaram melhor QV em relação aos com idade > 13 anos, possivelmente indicando melhor funcionalidade e menos conflitos emocionais e psicológicos

Using a Bayesian change-point statistical model with autoregressive terms to study the monthly number of dispensed asthma medications by public health services

In this paper, it is proposed a Bayesian analysis of a time series in the presence of a random change-point and autoregressive terms. The development of this model was motivated by a data set related to the monthly number of asthma medications dispensed by the public health services of Ribeirao Preto, Southeast Brazil, from 1999 to 2011. A pronounced increase trend has been observed from 1999 to a specific change-point, with a posterior decrease until the end of the series. In order to obtain estimates for the parameters of interest, a Bayesian Markov Chain Monte Carlo (MCMC) simulation procedure using the Gibbs sampler algorithm was developed. The Bayesian model with autoregressive terms of order 1 fits well to the data, allowing to estimate the change-point at July 2007, and probably reflecting the results of the new health policies and previously adopted programs directed toward patients with asthma. The results imply that the present model is useful to analyse the monthly number of dispensed asthma medications and it can be used to describe a broad range of epidemiological time series data where a change-point is present

Diagnostic tests in the context of the health technologies assessment: approaches, methods, and interpretation

As Avaliações de Tecnologias em Saúde (ATS) no mundo todo, predominantemente tem sido focadas em medicamentos, dispositivos médicos terapêuticos e procedimentos, sobretudo, os cirúrgicos. Apesar de sua inquestionável importância na história natural de um grande número de doenças e do impacto econômico associado ao seu uso, os testes e exames diagnósticos (TED), considerando-se suas qualidades e consequentemente a acurácia dos mesmos, tem sido pouco avaliados no contexto da ATS. Há nítida escassez de estudos que avaliam os TED tanto do ponto de vista clínico e de segurança para o paciente, quanto do econômico. O propósito desse artigo é apresentar e discutir os conceitos inerentes ao uso dos TED, as abordagens para seu emprego, as metodologias de avaliação de suas propriedades e acurácia, bem como a interpretação de resultados dos TED, sejam eles realizados individualmente, ou sob a forma de síntese de estudos de acurácia. Espera-se que esse texto possa contribuir para melhor compreensão das especificidades encontradas nos estudos dos TED e estimular sua inclusão nas ATS.The Health Technology Assessments (HTA) worldwide has been predominantly focused on drugs, medical devices and therapeutic procedures, above all, the surgeries. Despite its unquestionable importance in the natural history of a large number of diseases and of the economic impact associated with its use, the diagnostic exam and tests (DET), considering their qualities and hence the accuracy thereof, has been not evaluated in the context of the HTA. There is a clear shortage of studies that evaluate the DET, both clinician and patient safety, and economical. The purpose of this article is to present and discuss the concepts inherent in the use of DET, the approaches to your employ, the methodologies of evaluation of their properties and accuracy, as well as the interpretation of results DET studies, whether performed individually or in the form of synthesis of studies of accuracy. It is hoped that this text may contribute to better understanding of the specifics found in studies of DET and encourage their inclusion in the HTA

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio