953 resultados para Comparative methods
Resumo:
Objective: The study compared the prevalence, correlates of functional impairment, and service utilization for eating disorders across Latinos, Asians, and African Americans living in the United States to non-Latino Whites. Method: Pooled data from the NIMH Collaborative Psychiatric Epidemiological Studies (CPES; NIMH, 2007) were used. Results: The prevalence of anorexia nervosa (AN) and binge-eating disorder (BED) were similar across all groups examined, but bulimia nervosa (BN) was more prevalent among Latinos and African Americans than non-Latino Whites. Despite similar prevalence of BED among ethnic groups examined, lifetime prevalence of any binge eating (ABE) was greater among each of the ethnic minority groups in comparison to non-Latino Whites. Lifetime prevalence of mental health service utilization was lower among ethnic minority groups studied than for non-Latino Whites for respondents with a lifetime history of any eating disorder. Discussion: These findings suggest the need for clinician training and health policy interventions to achieve optimal and equitable care for eating disorders across all ethnic groups in the United States. (C) 2010 by Wiley Periodicals, Inc.
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A flow cytometry-adapted fluorescent antibody to membrane antigen (FAMA) assay to detect IgG antibodies against varicella-zoster virus (VZV) was developed and tested in 62 serum samples, showing 90.32% accuracy obtained from a receiver operating characteristic (ROC) curve with a 0.9125 (95% confidence interval [CI], 0.829 to 1.00) area below the curve compared to the result with standard FAMA.
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Background and objective: Dynamic indices represented by systolic pressure variation and pulse pressure variation have been demonstrated to be more accurate than filling pressures in predicting fluid responsiveness. However, the literature is scarce concerning the impact of different ventilatory modes on these indices. We hypothesized that systolic pressure variation or pulse pressure variation could be affected differently by volume-controlled ventilation and pressure-controlled ventilation in an experimental model, during normovolaemia and hypovolaemia. Method: Thirty-two anaesthetized rabbits were randomly allocated into four groups according to ventilatory modality and volaemic status where G1-ConPCV was the pressure-controlled ventilation control group, G2-HemPCV was associated with haemorrhage, G3-ConVCV was the volume-controlled ventilation control group and G4-HemVCV was associated with haemorrhage. In the haemorrhage groups, blood was removed in two stages: 15% of the estimated blood volume withdrawal at M1, and, 30 min later, an additional 15% at M2. Data were submitted to analysis of variance for repeated measures; a value of P < 0.05 was considered to be statistically significant. Results: At MO (baseline), no significant differences were observed among groups. At M1, dynamic parameters differed significantly among the control and hypovolaemic groups (P < 0.05) but not between ventilation modes. However, when 30% of the estimated blood volume was removed (M2), dynamic parameters became significantly higher in animals under volume-controlled ventilation when compared with those under pressure-controlled ventilation. Conclusions: Under normovolaemia and moderate haemorrhage, dynamic parameters were not influenced by either ventilatory modalities. However, in the second stage of haemorrhage (30%), animals in volume-controlled ventilation presented higher values of systolic pressure variation and pulse pressure variation when compared with those submitted to pressure-controlled ventilation.
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Objective: To develop a model to predict the bleeding source and identify the cohort amongst patients with acute gastrointestinal bleeding (GIB) who require urgent intervention, including endoscopy. Patients with acute GIB, an unpredictable event, are most commonly evaluated and managed by non-gastroenterologists. Rapid and consistently reliable risk stratification of patients with acute GIB for urgent endoscopy may potentially improve outcomes amongst such patients by targeting scarce health-care resources to those who need it the most. Design and methods: Using ICD-9 codes for acute GIB, 189 patients with acute GIB and all. available data variables required to develop and test models were identified from a hospital medical records database. Data on 122 patients was utilized for development of the model and on 67 patients utilized to perform comparative analysis of the models. Clinical data such as presenting signs and symptoms, demographic data, presence of co-morbidities, laboratory data and corresponding endoscopic diagnosis and outcomes were collected. Clinical data and endoscopic diagnosis collected for each patient was utilized to retrospectively ascertain optimal management for each patient. Clinical presentations and corresponding treatment was utilized as training examples. Eight mathematical models including artificial neural network (ANN), support vector machine (SVM), k-nearest neighbor, linear discriminant analysis (LDA), shrunken centroid (SC), random forest (RF), logistic regression, and boosting were trained and tested. The performance of these models was compared using standard statistical analysis and ROC curves. Results: Overall the random forest model best predicted the source, need for resuscitation, and disposition with accuracies of approximately 80% or higher (accuracy for endoscopy was greater than 75%). The area under ROC curve for RF was greater than 0.85, indicating excellent performance by the random forest model Conclusion: While most mathematical models are effective as a decision support system for evaluation and management of patients with acute GIB, in our testing, the RF model consistently demonstrated the best performance. Amongst patients presenting with acute GIB, mathematical models may facilitate the identification of the source of GIB, need for intervention and allow optimization of care and healthcare resource allocation; these however require further validation. (c) 2007 Elsevier B.V. All rights reserved.
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BACKGROUND CONTEXT: The vertebral spine angle in the frontal plane is an important parameter in the assessment of scoliosis and may be obtained from panoramic X-ray images. Technological advances have allowed for an increased use of digital X-ray images in clinical practice. PURPOSE: In this context, the objective of this study is to assess the reliability of computer-assisted Cobb angle measurements taken from digital X-ray images. STUDY DESIGN/SETTING: Clinical investigation quantifying scoliotic deformity with Cobb method to evaluate the intra- and interobserver variability using manual and digital techniques. PATIENT SAMPLE: Forty-nine patients diagnosed with idiopathic scoliosis were chosen based on convenience, without predilection for gender, age, type, location, or magnitude of the curvature. OUTCOME MEASURES: Images were examined to evaluate Cobb angle variability, end plate selection, as well as intra- and interobserver errors. METHODS: Specific software was developed to digitally reproduce the Cobb method and calculate semiautomatically the degree of scoliotic deformity. During the study, three observers estimated the Cobb angle using both the digital and the traditional manual methods. RESULTS: The results showed that Cobb angle measurements may be reproduced in the computer as reliably as with the traditional manual method, in similar conditions to those found in clinical practice. CONCLUSIONS: The computer-assisted method (digital method) is clinically advantageous and appropriate to assess the scoliotic curvature in the frontal plane using Cobb method. (C) 2010 Elsevier Inc. All rights reserved.
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This in vivo study evaluated the osteogenic potential of two proteins, recombinant human bone morphogenetic protein-2 (rhBMP-2) and a protein extracted from natural latex (Hevea brasiliensis, P-1), and compared their effects on bone defects when combined with a carrier or a collagen gelatin. Eighty-four (84) Wistar rats were divided into two groups, with and without the use of collagen gelatin, and each of these were divided into six treatment groups of seven animals each. The treatment groups were: (1) 5 mu g of pure rhBMP-2; (2) 5 mu g of rhBMP-2/monoolein gel; (3) pure monoolein gel; (4) 5 mu g of pure P-1; (5) 5 mu g of P-1/monoolein gel; (6) critical bone defect control. The animals were anesthetized and a 6 mm diameter critical bone defect was made in the left posterior region of the parietal bone. Animals were submitted to intracardiac perfusion after 4 weeks and the calvaria tissue was removed for histomorphometric analysis. In this experimental study, it was concluded that rhBMP-2 allowed greater new bone formation than P-1 protein and this process was more effective when the bone defect was covered with collagen gelatin (P < 0.05). Anat Rec, 293:794-801, 2010. (C) 2010 Wiley-Liss, Inc.
Resumo:
Introduction: The photoelasticity is used for assessing the tensions/deformations involved in photoelastic materials when submitted to a given load by the observation of optical effects. The screw performance and mechanical functions are directly associated to the quality of the screws fixation in the vertebrae. Photoelasticity is an important tool to perform comparative studies of this nature. Objective: The aim of this study was to compare, by using photoelasticity, internal stresses produced by the screw with an external diameter of 6 mm, when submitted to two different pullout strengths. Materials and Methods: For this, four photoelastic models were produced. The simulation was conducted by using two pullout strengths: 0.75 and 1.50 kgf. The maximum shear stresses were calculated on 19 points around the screws, using the Tardy compensation method. Results:The values of maximum shear stress were higher with the load of 1.50 kgf. Conclusion: Thus, the screw will be more susceptible to pullout when heavier loads are applied. According to our analysis, we also found that the site with the highest maximum shear stress was found to be at the peak of creast, particularly near the tips of the screws, regardless of the load employed.