Logistic regression analysis of potential prognostic factors for pulmonary thromboembolism

Objective: To identify potential prognostic factors for pulmonary thromboembolism (PTE), establishing a mathematical model to predict the risk for fatal PTE and nonfatal PTE.Method: the reports on 4,813 consecutive autopsies performed from 1979 to 1998 in a Brazilian tertiary referral medical school were reviewed for a retrospective study. From the medical records and autopsy reports of the 512 patients found with macroscopically and/or microscopically,documented PTE, data on demographics, underlying diseases, and probable PTE site of origin were gathered and studied by multiple logistic regression. Thereafter, the jackknife method, a statistical cross-validation technique that uses the original study patients to validate a clinical prediction rule, was performed.Results: the autopsy rate was 50.2%, and PTE prevalence was 10.6%. In 212 cases, PTE was the main cause of death (fatal PTE). The independent variables selected by the regression significance criteria that were more likely to be associated with fatal PTE were age (odds ratio [OR], 1.02; 95% confidence interval [CI], 1.00 to 1.03), trauma (OR, 8.5; 95% CI, 2.20 to 32.81), right-sided cardiac thrombi (OR, 1.96; 95% CI, 1.02 to 3.77), pelvic vein thrombi (OR, 3.46; 95% CI, 1.19 to 10.05); those most likely to be associated with nonfatal PTE were systemic arterial hypertension (OR, 0.51; 95% CI, 0.33 to 0.80), pneumonia (OR, 0.46; 95% CI, 0.30 to 0.71), and sepsis (OR, 0.16; 95% CI, 0.06 to 0.40). The results obtained from the application of the equation in the 512 cases studied using logistic regression analysis suggest the range in which logit p > 0.336 favors the occurrence of fatal PTE, logit p < - 1.142 favors nonfatal PTE, and logit P with intermediate values is not conclusive. The cross-validation prediction misclassification rate was 25.6%, meaning that the prediction equation correctly classified the majority of the cases (74.4%).Conclusions: Although the usefulness of this method in everyday medical practice needs to be confirmed by a prospective study, for the time being our results suggest that concerning prevention, diagnosis, and treatment of PTE, strict attention should be given to those patients presenting the variables that are significant in the logistic regression model.

Logistic regression to estimate the welfare of broiler breeders in relation to environmental and behavioral variables

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alterações do fluxo sanguíneo em artéria umbilical na síndrome hipertensiva gestacional e suas implicações nos resultados neonatais

OBJETIVO: Avaliar as características antropométricas, a morbidade e mortalidade de recém-nascidos (RN) prematuros nascidos vivos de mães hipertensas em função da presença ou não de diástole zero (DZ) ou reversa (DR) na doplervelocimetria arterial umbilical. MÉTODOS: Estudo prospectivo, envolvendo RN prematuros nascidos vivos de gestantes hipertensas, com idade gestacional entre 25 e 33 semanas, submetidas à doplervelocimetria da artéria umbilical nos 5 dias que antecederam o parto, realizado no Hospital do Distrito Federal, entre 1º de novembro de 2009 e 31 de outubro de 2010. Os RN foram estratificados em dois grupos, conforme o resultado da doplervelocimetria da artéria umbilical: Gdz/dr=presença de diástole zero (DZ) ou diástole reversa (DR) e Gn=doplervelocimetria normal. Medidas antropométricas ao nascimento, morbidades e mortalidade neonatal foram comparadas entre os dois grupos. RESULTADOS: Foram incluídos 92 RN, assim distribuídos: Gdz/dr=52 RN e Gn=40 RN. No Gdz/dr a incidência de RN pequenos para idade gestacional foi significativamente maior, com risco relativo de 2,5 (IC95% 1,7‒3,7). No grupo Gdz/dr os RN permaneceram mais tempo em ventilação mecânica mediana 2 (0‒28) e no Gn mediana 0,5 (0‒25), p=0,03. A necessidade de oxigênio aos 28 dias de vida foi maior no Gdz/dr do que no Gn (33 versus10%; p=0,01). A mortalidade neonatal foi maior em Gdz/dr do que em Gn (36 versus 10%; p=0,03; com risco relativo de 1,6; IC95% 1,2 - 2,2). Nessa amostra a regressão logística mostrou que a cada 100 gramas a menos de peso ao nascer no Gdz/dr a chance de óbito aumentou 6,7 vezes (IC95% 2,0 - 11,3; p<0,01). CONCLUSÃO: em RN prematuros de mães hipertensas com alteração na doplervelocimetria da artéria umbilical a restrição do crescimento intrauterino é frequente e o prognóstico neonatal pior, sendo elevado o risco de óbito relacionado ao peso ao nascimento.

An emergy-based evaluation of a reverse logistics network for steel recycling

Efficient implementation of recycling networks requires appropriate logistical structures for managing the reverse flow of materials from users to producers. The steel sheet distributor studied had established a protocol for scrap recovery with the steel plant and its customers. The company invested in producing containers, hiring a specialized labor force and in purchasing trucks for container transportation to implement the logistics network for recycling. That network interconnected the company with two kinds of customers: the ones returning scrap and the ones who preferred to continue business-as-usual. The logistical network was analyzed using emergy synthesis, and the data obtained were used to evaluate and compare the system's environmental costs and benefits from the perspective of the distributor and the steel plant operator. The use of emergy ternary diagrams provided a way to assess recycle strategies to compare the relative economic and environmental benefits of the logistical network implemented. The minimum quantity of scrap that the distributor must recover to improve environmental benefits was determined allowing decision on whether it is worth keeping the system running. The new assessment method proposed also may help policy-makers to create strategies to reward or incentive users of reverse logistics, and help to establish regulations, by decreasing taxes or stimulating innovation, for effectively implement the National Policy on Solid Waste. (C) 2013 Elsevier Ltd. All rights reserved.

Microbiota bucal de pacientes HIV positivos: relação com o uso de drogas antirretrovirais e condições de saúde

Pós-graduação em Odontologia - FOA