Objective: To develop and validate a Portuguese-language version of the Asthma Control Test (ACT) for use in Brazil. Methods: The study comprised 290 asthma outpatients over 12 years of age. The patients completed the ACT questionnaire and had an appointment with a pulmonologist in order to assess asthma control in two visits. In the first visit, the patients also underwent spirometry. The second visit took place at least four weeks later. Results: We found that a cut-off score of 18 points-to differentiate between subjects with controlled asthma and those with uncontrolled asthma-had a sensitivity of 93%, a specificity of 74%, a negative predictive value of 86% and a positive predictive value of 85%. The positive and negative likelihood ratios were 3.58 and 0.09, respectively. The questionnaire has an outstanding capacity to differentiate uncontrolled asthma from controlled asthma, with an area under the ROC curve of 0.904. The patients whose symptoms remained stable between the two visits had similar scores, demonstrating good test-retest reproducibility, with an intraclass correlation coefficient of 0.93. The patients whose symptoms improved in the second visit had significantly higher scores, demonstrating good responsiveness of the questionnaire in the identification of changes in disease control. Conclusions: The Portuguese-language version of the ACT showed good test-retest reproducibility and was capable of discriminating the levels of asthma control and detecting changes in asthma control in a population of patients with a low level of education and low family income at a public health facility in Brazil.Keywords: Asthma; Questionnaires; Validation studies; Signs and symptoms. ResumoObjetivo: Desenvolver e validar uma versão do Asthma Control Test (ACT, Teste de Controle da Asma) em português para uso no Brasil. Métodos: Foram estudados 290 pacientes ambulatoriais com asma maiores que 12 anos. Os pacientes responderam ao ACT e foram examinados por um pneumologista para avaliar o controle da asma em duas visitas. Na primeira visita, também realizaram prova de função pulmonar. A segunda visita foi realizada ao menos quatro semanas depois da primeira. Resultados: Utilizando-se como ponto de corte um escore de 18 para diferenciar asma controlada de asma não controlada, foram encontradas sensibilidade de 93%, especificidade de 74%, valor preditivo negativo de 86% e valor preditivo positivo de 85%. As razões de verossimilhança positiva e negativa foram, respectivamente, 3,58 e 0,09. O questionário tem grande capacidade de discriminar asma controlada de asma não controlada, com uma área sob a curva ROC de 0,904. Os pacientes que mantiveram os sintomas estáveis na segunda avaliação tiveram pontuação semelhante no questionário, indicando uma boa reprodutibilidade teste-reteste, com um coeficiente de correlação intraclasse de 0,93. Os pacientes que melhoraram os sintomas na segunda avaliação tiveram pontuação do questionário significativamente melhor, indicando uma boa responsividade do questionário para ...

The incidence of poor perception of asthma control in asthma patients is high, especially in elderly patients with lower income and a lower degree of asthma severity.

The objective of this study is to evaluate the Joule–Thomson effect, which occurs at a valve due to the throttling process for mixtures containing polymers and copolymers. For economic and safety reasons, it is essential to know the temperature change in industrial processes due to the pressure drop in the valve. The modeling of this phenomenon in mixtures containing polymers and copolymers, however, remains a challenge for process engineers, and the literature rarely reports studies on the subject. This work proposes a model that can directly compute temperature due to the throttling process using the concept of residual enthalpy and the perturbed-chain statistical associating fluid theory equation of state, instead of solely computing the Joule–Thomson coefficient. Systems containing poly­(ethylene-co-vinyl acetate) and low-density polyethylene were chosen as case studies because of the need for temperature control at the reactor outlet and separation processes. The model prediction was validated using industrial data, and deviations of approximately 2% between the model prediction and the experimental temperature indicate the efficiency of the proposed approach when describing the temperature due to the throttling of both systems that are being studied.