Abstract We consider a finite population mixed model that accommodates response errors and show how to obtain optimal estimators of the finite population parameters in a pretest-posttest context. We illustrate the method with the estimation of the difference in gain between two interventions and consider a simulation study to compare the empirical version of the proposed estimator (obtained by replacing variance components with estimates) with the estimator obtained via covariance analysis usually employed in such settings. The results indicate that in many instances, the proposed estimator has a smaller mean squared error than that obtained from the standard analysis of covariance model.

Resumen Se considera un modelo mixto para población finita que tiene en cuenta el error de respuesta y que arroja estimadores óptimos de los parámetros de la población finita, para analizar datos de estudios con estructura del tipo pretest-posttest. Se ilustra el método estimando la diferencia en ganancia entre dos intervenciones y se considera un estudio de simulación para comparar la versión empírica del estimador propuesto (obtenido al reemplazar las componentes de varianza con sus estimativas) con el estimador obtenido vía análisis de covarianza, que es usualmente empleado en este tipo de estudios. Los resultados indican que en muchas circunstancias, el estimador propuesto tiene menor error cuadrático medio que el obtenido del análisis estándar usando el modelo de covarianza.

OBJECTIVES: An objective of clinical autopsies is to determine the final cause of death and the pathological changes that may have triggered it. Despite advances in Medicine, the level of discrepancy between clinical and autopsy diagnoses remains significant. The aim of this study was to compare the data obtained from autopsies carried out at the São Bernardo do Campo/SP Death Verification Section with clinical diagnostic hypotheses proposed during medical care. METHOD: This was a retrospective study involving the comparison of necroscopic reports issued by the São Bernardo do Campo/São Paulo Death Verification Section in 2014 and 2015 and the Cadaver Referral Guides completed by attending physicians prior to the necroscopic examination. RESULTS: A total of 465 cases were analyzed. In general, discrepancies between the clinical diagnostic hypothesis and the autopsy diagnosis occurred in 28% of the cases. A logistic regression model, with diagnostic discrepancy as a response variable and sex, age, duration of care, type of institution providing medical care and organ system as explanatory variables, was fit to the data; the results indicated that all explanatory variables with the exception of organ system are not significant (p>0.132). CONCLUSIONS: Discrepancies between clinical diagnostic hypotheses and autopsy diagnoses continue to occur, despite new developments in complementary examinations and therapies. The odds of a discrepancy when patients present with diseases of the cardiac system are greater than those when there are problems in the vascular, endocrine and neurological systems.

OBJETIVO: Analisar características ecocardiográficas e manifestações clínicas na evolução de recém-nascidos pré-termo com persistência do canal arterial e identificar indicadores mais confiáveis do fechamento espontâneo deste. MÉTODOS: Sessenta e um recém-nascidos pré-termo com idade gestacional de 30±2 semanas (26-34 semanas) peso de 1,2±0,2 kg (0,7-1,7 kg) foram avaliados semanalmente desde o terceiro dia de vida até o termo através de ecocardiograma. O diâmetro do canal arterial e medidas das cavidades cardíacas foram determinados. Avaliação clínica procurou detectar sinais clínicos de persistência do canal arterial. Recém-nascidos pré-termo com persistência do canal arterial foram divididos em dois grupos: Grupo A, onde houve fechamento espontâneo do canal arterial, e Grupo B, onde não houve. Análise estatística foi realizada através do teste t e curva ROC. RESULTADOS: Vinte e um (34,4%) recém-nascidos pré-termo apresentaram persistência do canal arterial no terceiro dia de vida, sendo sete do grupo A e 14 do grupo B. Sinais clínicos de persistência do canal arterial ocorreram em 14,3% do grupo A e 71,4% do grupo B (p = 0,013). Persistência do canal arterial aumentou significativamente os diâmetros do átrio e ventrículo esquerdo e débito cardíaco aórtico. Diâmetro médio do canal arterial foi maior no grupo B (2,6±0,6 mm versus 1,4±0,6 mm; p = 0,003). Área abaixo da curva ROC em relação ao diâmetro do canal foi de 0,93 (p = 0,003), sendo 1,7 mm o ponto de corte de maior sensibilidade (100%) para identificar os recém-nascidos onde o canal arterial não apresentará fechamento espontâneo e 2,2 mm o ponto de maior especificidade (100%). CONCLUSÕES: Em recém-nascidos pré-termo, uma persistência do canal arterial maior que 2,2 mm de diâmetro no terceiro dia de vida prediz ausência de fechamento espontâneo e sugere necessidade de tratamento, especialmente quando da presença de algum sinal clínico associado.

OBJECTIVE: To identify clinical and echocardiography predictors of the spontaneous closure of patent ductus arteriosus in preterm neonates. METHODS: Sixty-one consecutive preterm neonates (gestational age 30±2 weeks, birth weight 1.2±0.2 kg) were evaluated by echocardiogram on their third day of life and those with patent ductus arteriosus were selected for a prospective cohort. Echocardiography was repeated weekly until they reached term. Based on their progress, the sample population was divided into two groups, depending on whether spontaneous closure of patent ductus arteriosus took place (Group A) or not (Group B). The prevalence of clinical signs of patent ductus arteriosus and echocardiography findings at baseline were compared between the groups. RESULTS: Patent ductus arteriosus was found in 21 neonates (34%). Spontaneuous closure was observed during follow-up of seven patients (Group A, 33% of those with patent ductus arteriosus), in contrast with the remaining 14 patients (Group B, 67%). Clinical signs of patent ductus arteriosus were present in 14% of the patients in Group A, compared with 71% in group B (p = 0.01). At baseline, Group B had a larger ductus diameter in relation to Group A (2.6±0.6 mm vs. 1.4±0.6 mm; p = 0.003). The area under the ROC curve in relation to ductus diameter was 0.93 (p = 0.003) and 100% sensitivity for identifying cases without spontaneous closure was obtained at the cutoff point of 1.7 mm, while 100% specificity was observed taking 2.2 mm as the cutoff. CONCLUSIONS: In preterm neonates, a patent ductus arteriosus greater than 2.2 mm on the third day of life predicts no spontaneous closure and suggests a need for early treatment, especially when associated with clinical signs.