Browsing by Issue Date, starting with "2023-02-17"
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- Unsupervised algorithms to identify potential under-coding of secondary diagnoses in hospitalisations databases in PortugalPublication . Portela, Diana ; Amaral, Rita; Rodrigues, Pedro P. ; Freitas, Alberto ; Costa, Elísio ; Fonseca, João A. ; Sousa-Pinto, BernardoQuantifying and dealing with lack of consistency in administrative databases (namely, under-coding) requires tracking patients longitudinally without compromising anonymity, which is often a challenging task. This study aimed to (i) assess and compare different hierarchical clustering methods on the identification of individual patients in an administrative database that does not easily allow tracking of episodes from the same patient; (ii) quantify the frequency of potential under-coding; and (iii) identify factors associated with such phenomena. We analysed the Portuguese National Hospital Morbidity Dataset, an administrative database registering all hospitalisations occurring in Mainland Portugal between 2011–2015. We applied different approaches of hierarchical clustering methods (either isolated or combined with partitional clustering methods), to identify potential individual patients based on demographic variables and comorbidities. Diagnoses codes were grouped into the Charlson an Elixhauser comorbidity defined groups. The algorithm displaying the best performance was used to quantify potential under-coding. A generalised mixed model (GML) of binomial regression was applied to assess factors associated with such potential under-coding. We observed that the hierarchical cluster analysis (HCA) + k-means clustering method with comorbidities grouped according to the Charlson defined groups was the algorithm displaying the best performance (with a Rand Index of 0.99997). We identified potential under-coding in all Charlson comorbidity groups, ranging from 3.5% (overall diabetes) to 27.7% (asthma). Overall, being male, having medical admission, dying during hospitalisation or being admitted at more specific and complex hospitals were associated with increased odds of potential under-coding. We assessed several approaches to identify individual patients in an administrative database and, subsequently, by applying HCA + k-means algorithm, we tracked coding inconsistency and potentially improved data quality. We reported consistent potential under-coding in all defined groups of comorbidities and potential factors associated with such lack of completeness. Our proposed methodological framework could both enhance data quality and act as a reference for other studies relying on databases with similar problems.
- Efeito imediato da técnica de rotação cervical grau II na sensação de posição articular em indivíduos com dor não específicaPublication . Rodrigues, Elisa; Brochado, Gabriela; Moura Bessa, Isabel; Gonçalves, Paulo; Domingos, João; Crasto, CarlosA mobilização articular passiva em indivíduos com dor cervical possui eficácia reconhecida no alívio da dor e no aumento da amplitude articular, mas há poucos estudos sobre a sua influência na capacidade propriocetiva. Estudar o efeito imediato da técnica de rotação cervical grau II na sensação de posição articular, em jovens adultos com e sem dor cervical unilateral de origem não específica. Estudo quase experimental, duplamente cego, numa amostra de conveniência de 37 indivíduos (18 a 24 anos de ambos os sexos) divididos em 2 grupos: 22 sem dor e 15 com dor cervical. O instrumento Cervical Range of Motion foi utilizado para avaliar a sensação de posição articular ativa da cervical a 30⁰ de rotação, para a direita e para a esquerda, antes e imediatamente após a execução da técnica de mobilização articular de rotação cervical grau II de Maitland (quatro mobilizações de 30 segundos cada). O teste foi repetido seis vezes para cada lado. Calculou-se o erro absoluto e o erro variável utilizando-se o teste t para comparação entre os grupos e momentos com nível de significância de 5%. Apenas se observaram diferenças significativas entre grupos no erro variável na rotação esquerda após a realização da técnica e entre momentos na rotação esquerda e direita no grupo sem dor sendo, no entanto, de magnitudes iguais ou inferiores a 1⁰ em média. A técnica de rotação cervical grau II não parece produzir efeitos imediatos clinicamente relevantes na precisão e consistência do reposicionamento avaliada a 30⁰ de rotação.
- Exploiting kinetic features of ORAC assay for evaluation of radical scavenging capacityPublication . Carvalho, Joana R. B.; Meireles, Andreia N.; Marques, Sara S.; Gregório, Bruno J. R.; Ramos, Inês I.; Silva, Eduarda M. P.; Barreiros, Luisa; Segundo, Marcela A.The analysis and interpretation of data retrieved from Oxygen Radical Absorbance Capacity (ORAC) assays represent a challenging task. ORAC indexes originate from different mathematical approaches often lacking correct elucidation of kinetic features concerning radical scavenging reactions by antioxidant compounds. In this work, the expression of ORAC values as area under fluorescein (FL) decay curves (AUC) and lag time are critically compared. This multi-parametric analysis showed the extension of radical scavenging reactions beyond the lag time period for caffeic acid, gallic acid, reduced glutathione and quercetin, extending their antioxidant protection of FL. Ethanol delayed the reaction of both FL and antioxidant compounds with free radical species generated from 2,20 -azobis(2-amidinopropane) dihydrochloride thermolysis. Trolox equivalent values, commonly used to express ORAC values, were more affected by the differences in radical scavenging kinetics between the reference and the tested antioxidant compounds when calculated from AUC than from lag time. These findings stressed the importance of choosing calibrator compounds presenting ORAC kinetics similar to samples to prevent biased estimation of the antioxidant capacity. Additionally, the framework proposed here provides a sustainable analytical method for the evaluation of antioxidant capacity, with an AGREE score of 0.73.