961 resultados para ROC


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

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Purpose: To compare visual inspection (VI), radiographic examination (RX) and the laser fluorescence device DIAGNOdent (L), as well as their combinations in vitro regarding treatment decisions for occlusal surfaces. Methods: 72 extracted human permanent teeth (molars and premolars) were used. Treatment decisions were recorded by three calibrated examiners, and the options available were fissure sealant and conservative restoration. For validation of treatment decisions, the teeth were sectioned and examined in a stereomicroscope. Thereafter, dental slices were scanned and the images were edited to facilitate classification of existing carious lesions. Intra and inter-examiner reproducibility for the determination of treatment plans were calculated using Cohen's kappa test (95%-CI). Sensitivity, specificity, positive and negative predictive values, and the area under the ROC curve were also calculated. Results: VI and L provided on average the greatest intra- and inter-examiner reproducibility, respectively. Although the combination of diagnostic methods may decrease both intra- and inter examiners reproducibility, combination of VI, L and RX resulted in the greatest sensitivity, being statistically superior to RX and L. There was more inter-examiner agreement for the option of restorative treatment, while the use of sealants as a treatment option yielded the lowest values. Negative predictive values were numerically inferior to positive predictive values, indicating that the examiners preferred not to restore a carious tooth than to proceed operatively in an intact tooth. The combination of the three methods studied showed the best results in determining treatment plans for occlusal surfaces, when compared to the other types of exams. on the other hand, radiographic examination and laser fluorescence were less efficient when used alone.

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Objectives:The aim of this in vitro study was to assess the inter- and intra-examiner reproducibility and the accuracy of the International Caries Detection and Assessment System-II (ICDAS-II) in detecting occlusal caries.Methods:One hundred and sixty-three molars were independently assessed twice by two experienced dentists using the 0- to 6-graded ICDAS-II. The teeth were histologically prepared and classified using two different histological systems [Ekstrand et al. (1997) Caries Research vol. 31, pp. 224-231; Lussi et al. (1999) Caries Research vol. 33, pp. 261-266] and assessed for caries extension. Sensitivity, specificity, accuracy and area under the ROC curve (A(z)) were obtained at D(2) and D(3) thresholds. Unweighted kappa coefficient was used to assess inter- and intra-examiner reproducibility.Results:For the Ekstrand et al. histological classification the sensitivity was 0.99 and 1.00, specificity 1.00 and 0.69 and accuracy 0.99 and 0.76 at D(2) and D(3), respectively. For the Lussi et al. histological classification the sensitivity was 0.91 and 0.75, specificity 0.47 and 0.62 and accuracy 0.86 and 0.68 at D(2) and D(3), respectively. The A(z) varied from 0.54 to 0.73. The inter- and intra-examiner kappa values were 0.51 and 0.58, respectively.Conclusions:ICDAS-II presented good reproducibility and accuracy in detecting occlusal caries, especially caries lesions in the outer half of the enamel.

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This study compared the performance of fluorescence-based methods, radiographic examination, and International Caries Detection and Assessment System (ICDAS) II on occlusal surfaces. One hundred and nineteen permanent human molars were assessed twice by 2 experienced dentists using the laser fluorescence (LF and LFpen) and fluorescence camera (FC) devices, ICDAS II and bitewing radiographs (BW). After measuring, the teeth were histologically prepared and assessed for caries extension. The sensitivities for dentine caries detection were 0.86 (FC), 0.78 (LFpen), 0.73 (ICDAS II), 0.51 (LF) and 0.34 (BW). The specificities were 0.97 (BW), 0.89 (LF), 0.65 (ICDAS II), 0.63 (FC) and 0.56 (LFpen). BW presented the highest values of likelihood ratio (LR)+ (12.47) and LR- (0.68). Rank correlations with histology were 0.53 (LF), 0.52 (LFpen), 0.41 (FC), 0.59 (ICDAS II) and 0.57 (BW). The area under the ROC curve varied from 0.72 to 0.83. Inter- and intraexaminer intraclass correlation values were respectively 0.90 and 0.85 (LF), 0.93 and 0.87 (LFpen) and 0.85 and 0.76 (FC). The ICDAS II kappa values were 0.51 (interexaminer) and 0.61 (intraexaminer). The BW kappa values were 0.50 (interexaminer) and 0.62 (intraexaminer). The Bland and Altman limits of agreement were 46.0 and 38.2 (LF), 55.6 and 40.0 (LFpen) and 1.12 and 0.80 (FC), for intra- and interexaminer reproducibilities. The posttest probability for dentine caries detection was high for BW and LF. In conclusion, LFpen, FC and ICDAS II presented better sensitivity and LF and BW better specificity. ICDAS II combined with BW showed the best performance and is the best combination for detecting caries on occlusal surfaces. Copyright (C) 2008 S. Karger AG, Basel.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Objectives: (1) To evaluate the intraobserver agreement related to image interpretation and (2) to compare the accuracy of 100%, 200% and 400% zoomed digital images in the detection of simulated periodontal bone defects.Methods: Periodontal bone defects were created in 60 pig hemi-mandibles with slow-speed burs 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm and 3.0 mm in diameter. 180 standardized digital radiographs were made using Schick sensor and evaluated at 100%, 200% and 400% zooming. The intraobserver agreement was estimated by Kappa statistic (kappa). For the evaluation of diagnostic accuracy receiver operating characteristic (ROC) analysis was performed followed by chi-square test to compare the areas under ROC curves according to each level of zooming.Results: For 100%, 200% and 400% zooming the intraobserver agreement was moderate (kappa = 0.48, kappa = 0.54 and kappa = 0.43, respectively) and there were similar performances in the discrimination capacity, with ROC areas of 0.8611 (95% CI: 0.7660-0.9562), 0.8600 (95% CI: 0.7659-0.9540), and 0.8368 (95% CI: 0.7346-0.9390), respectively, with no statistical significant differences (chi(2)-test; P = 0.8440).Conclusions: A moderate intraobserver agreement was observed in the classification of periodontal bone defects and the 100%, 200% and 400% zoomed digital images presented similar performances in the detection of periodontal bone defects.

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Desequilíbrio é um dos muitos fatores de risco que aumenta a susceptibilidade de um idoso a quedas. O equilíbrio pode ser avaliado mediante testes posturais e de sensibilidade plantar. OBJETIVO: Avaliar a ocorrência de desequilíbrio e perda de sensibilidade cutânea plantar em idosos da comunidade e verificar a existência de associação entre ambas as alterações. CASUÍSTICA E MÉTODOS: Estudo transversal descritivo envolvendo 45 idosos submetidos à escala de equilíbrio de Berg (EEB) e ao teste de sensibilidade plantar com monofilamento de nylon. Foram utilizados os testes qui-quadrado e exato de Fisher e elaboradas curvas ROC para estudo da sensibilidade e especificidade da EEB. RESULTADOS: Idosos com alteração do equilíbrio e da sensibilidade cutânea foram em número de 2 e 4, respectivamente. Houve associação significativa entre queixa de desequilíbrio e perda da sensibilidade (p = 0,047) e ocorreu concordância razoável (Kappa: 0,6457) entre a EEB e o teste da sensibilidade. Verificou-se também associação significativa entre 6 dos 14 tarefas da EEB e o teste sensorial. CONCLUSÃO: Idosos vivendo com independência na comunidade, em sua maioria, apresentam equilíbrio e sensibilidade cutânea plantar normais. Quando alteradas estas funções mostram-se associadas de forma que, se os testes forem realizados conjuntamente, a precisão da avaliação do equilíbrio idoso aumenta.

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Background: Recent studies have identified that a higher resting heart rate (RHR) is associated with elevated blood pressure, independent of body fatness, age and ethnicity. However, it is still unclear whether RHR can also be applied as a screening for other risk factors, such as hyperglycemia and dyslipidemia. Thus, the purpose of the presented study was to analyze the association between RHR, lipid profile and fasting glucose in obese children and adolescents.Methods: The sample was composed of 180 obese children and adolescents, aged between 7-16 years. Whole-body and segmental body composition were estimated by Dual-energy X-ray absorptiometry. Resting heart rate (RHR) was measured by heart rate monitors. The fasting blood samples were analyzed for serum triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and glucose, using the colorimetric method.Results: Fasting glucose, TC, triglycerides, HDL-C, LDL-C and RHR were similar in both genders. The group of obese subjects with a higher RHR presented, at a lower age, higher triglycerides and TC. There was a significant relationship between RHR, triglycerides and TC. In the multivariate model, triglycerides and TC maintained a significant relationship with RHR independent of age, gender, general and trunk adiposity. The ROC curve indicated that RHR has a high potential for screening elevated total cholesterol and triglycerides as well as dyslipidemia.Conclusion: Elevated RHR has the potential to identify subjects at an increased risk of atherosclerosis development.

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Objectives: To evaluate the accuracy of three different cutoff points for the detection of high blood pressure in adolescents, given the strong relationship between overweight and high blood pressure levels.Methods: A total of 1,021 adolescents of both sexes were enrolled in the study, selected at random from public and private schools in Londrina, Brazil. Their body weight was measured using a digital balance, and their height with a portable stadiometer with a maximum extension of 2 meters. Arterial blood pressure was measured using an automatic apparatus. The capacity of body mass index to detect high blood pressure was gauged using ROC curves and their parameters (sensitivity, specificity, and area under the curve).Results: The cutoff points proposed in a Brazilian standard exhibited greater accuracy (males: 0.636 +/- 0.038; females: 0.585 +/- 0.043) than the cutoff points proposed in an international (males: 0.594 +/- 0.040; females: 0.570 +/- 0.044) and a North-American standard (males: 0.612 +/- 0.039; females: 0.578 +/- 0.044).Conclusions: The Brazilian proposal offered greatest accuracy for indicating high blood pressure levels.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In this work we rederive the Lamb-Retherford energy shift for an atomic electron in the presence of a thermal radiation. Using the Dalibard, Dupont-Roc and Cohen-Tannoudji (DDC) formalism, where physical observables are expressed as convolutions of suitable statistical functions, we construct the electromagnetic field propagator of thermo field dynamics in the Coulomb gauge in order to investigate finite temperature effects on the atomic energy levels. In the same context, we also analyze the problem of the ground state stability.

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In this work we reexamine quantum electrodynamics of atomic electrons in the Coulomb gauge in the dipole approximation and calculate the shift of atomic energy levels in the context of Dalibard, Dupont-Roc and Cohen-Tannoudji formalism by considering the variation rates of physical observable. We then analyze the physical interpretation of the ordering of operators in the dipole approximation interaction Hamiltonian in terms of field fluctuations and self-reaction of atomic electrons, discussing the arbitrariness in the statistical functions in second-order bound-state perturbation theory. (C) 2002 Elsevier B.V. B.V. All rights reserved.

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FUNDAMENTO: A medida precisa da pressão arterial é fundamental para a investigação científica ou decisão clínica. Nesse sentido, é importante verificar valores fornecidos por equipamentos eletrônicos. OBJETIVO: Validar o monitor Omron HEM 742 de medida de pressão arterial em adolescentes, segundo os critérios sugeridos pela British Hypertension Society. MÉTODOS: Participaram do estudo 150 adolescentes com idades entre 10 e 16 anos. O monitor automático Omron HEM 742 foi conectado em Y com equipamento auscultatório de coluna de mercúrio, e realizaram-se três avaliações simultâneas, calculando-se as diferenças entre os dois equipamentos. Para verificar a relação entre ambos, utilizaram-se o coeficiente de correlação intraclasse e a plotagem de Bland-Altman (concordância). A especificidade e a sensibilidade do aparelho foram determinadas pela curva ROC. RESULTADOS: A comparação entre as medidas acusou uma diferença menor ou igual a 5 mmHg em 67,3% dos valores sistólicos e 69,3% dos valores diastólicos; uma diferença menor ou igual a 10 mmHg ocorreu em 87,3% e 90,6% dos valores sistólicos e diastólicos, respectivamente; e uma diferença menor ou igual a 15 mmHg em 96,6% dos valores sistólicos e 97,3% dos diastólicos. Esses resultados indicam grau A segundo o protocolo da British Hypertension Society. Observou-se ainda elevada concordância nos valores obtidos por meio do monitor automático, e verificou-se que esse equipamento é capaz de identificar a presença ou a ausência da pressão arterial elevada. CONCLUSÃO: O monitor Omron HEM 742 mostrou-se válido para medidas de pressão arterial em adolescentes, conforme os critérios sugeridos pela British Hypertension Society.

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FUNDAMENTO: A obesidade está ligada à hipertensão arterial (HA) na infância. Entretanto, o papel da gordura como preditor de HA em adolescentes permanece desconhecido. OBJETIVO: Investigar a associação entre obesidade geral e abdominal com HA e identificar a sensibilidade e especificidade desses indicadores para detectar HA em adolescentes. MÉTODOS: A amostra consistiu em 1.021 adolescentes com idade de 10-17 anos. Os indivíduos foram classificados como normal, sobrepeso/obesidade, de acordo com as medidas do IMC, e como não-obeso com obesidade abdominal, de acordo com as medidas da circunferência da cintura (CC). A pressão arterial sistólica (PAS) e diastólica (PAD) foi avaliada através de um dispositivo oscilométrico. Regressão logística e curvas ROC foram usadas na análise estatística. RESULTADOS: A prevalência geral de HA foi 11,8% (13,4% em meninos e 10,2% em meninas). A prevalência de HA em meninos e meninas com sobrepeso/obesidade foi 10% e 11,1%, respectivamente. A prevalência de HA em meninos com obesidade abdominal foi 28,6%. Para ambos os sexos, o odds ratio (OR) para HA foi mais alto na obesidade abdominal do que no sobrepeso/obesidade geral (4,09 [OR IC95% = 2,57-6,51]) versus 1,83 [OR IC95% = 1,83-4,30]). O OR para HA foi mais alto quando sobrepeso/obesidade geral e obesidade abdominal estavam agrupados (OR = 4,35 [OR IC95% = 2,68 -7,05]), do que quando identificados como sobrepeso/obesidade geral ou obesidade abdominal apenas (OR = 1,32 [OR IC95% = 0,65- 2,68]). Entretanto, ambos os tipos de obesidade apresentavam baixo poder preditivo na detecção de HA. CONCLUSÃO: Obesidade geral e obesidade abdominal foram associadas com HA; entretanto, a sensibilidade e especificidade dessas variáveis na detecção de HA são baixas em adolescentes brasileiros.

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O objetivo do artigo foi avaliar o uso da lógica fuzzy para estimar possibilidade de óbito neonatal. Desenvolveu-se um modelo computacional com base na teoria dos conjuntos fuzzy, tendo como variáveis peso ao nascer, idade gestacional, escore de Apgar e relato de natimorto. Empregou-se o método de inferência de Mamdani, e a variável de saída foi o risco de morte neonatal. Criaram-se 24 regras de acordo com as variáveis de entrada, e a validação do modelo utilizou um banco de dados real de uma cidade brasileira. A acurácia foi estimada pela curva ROC; os riscos foram comparados pelo teste t de Student. O programa MATLAB 6.5 foi usado para construir o modelo. Os riscos médios foram menores para os que sobreviveram (p < 0,001). A acurácia do modelo foi 0,90. A maior acurácia foi com possibilidade de risco igual ou menor que 25% (sensibilidade = 0,70, especificidade = 0,98, valor preditivo negativo = 0,99 e valor preditivo positivo = 0,22). O modelo mostrou acurácia e valor preditivo negativo bons, podendo ser utilizado em hospitais gerais.