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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Bivariate meta-analysis of sensitivity and specificity of radiographers' plain radiograph reporting in clinical practice.

Brealey, S., Hewitt, C., Scally, Andy J., Hahn, S., Godfrey, C., Thomas, N. January 2009 (has links)
Studies of diagnostic accuracy often report paired tests for sensitivity and specificity that can be pooled separately to produce summary estimates in a meta-analysis. This was done recently for a systematic review of radiographers' reporting accuracy of plain radiographs. The problem with pooling sensitivities and specificities separately is that it does not acknowledge any possible (negative) correlation between these two measures. A possible cause of this negative correlation is that different thresholds are used in studies to define abnormal and normal radiographs because of implicit variations in thresholds that occur when radiographers' report plain radiographs. A method that allows for the correlation that can exist between pairs of sensitivity and specificity within a study using a random effects approach is the bivariate model. When estimates of accuracy as a fixed-effects model were pooled separately, radiographers' reported plain radiographs in clinical practice at 93% (95% confidence interval (CI) 92-93%) sensitivity and 98% (95% CI 98-98%) specificity. The bivariate model produced the same summary estimates of sensitivity and specificity but with wider confidence intervals (93% (95% CI 91-95%) and 98% (95% CI 96-98%), respectively) that take into account the heterogeneity beyond chance between studies. This method also allowed us to calculate a 95% confidence ellipse around the mean values of sensitivity and specificity and a 95% prediction ellipse for individual values of sensitivity and specificity. The bivariate model is an improvement on pooling sensitivity and specificity separately when there is a threshold effect, and it is the preferred method of choice.
42

Clinical decision rules to enable exclusion of acute coronary syndromes in Emergency Department patients with chest pain

Body, Richard January 2009 (has links)
Background: Diagnosis of acute coronary syndromes (ACS) in the Emergency Department (ED) is a topical and contentious issue. Current diagnostic techniques rely on hospital admission for troponin testing. Only a minority of those admitted prove to have ACS while unacceptable proportions of those discharged have unrecognised ACS. Aims: We aimed to evaluate the diagnostic and prognostic value of individual clinical findings and novel biomarkers in ED patients with suspected cardiac chest pain. We then aimed to derive a clinical decision rule (CDR) to potentially enable safe, immediate discharge of a proportion of patients from the ED while risk stratifying others to facilitate triage to an appropriate level of in-patient care. Methods: We recruited patients who presented to the ED with suspected cardiac chest pain. Variables that have previously been shown to predict diagnosis of acute myocardial infarction (AMI) or to predict outcome were prospectively recorded. Blood was drawn at presentation for levels of eight biomarkers. Patients underwent 12-hour troponin testing and were followed up for the composite primary outcome of AMI, death or urgent coronary revascularisation for six months. Variables that were univariate predictors (p<0.05) of outcome were entered into a multivariate analysis using recursive partitioning. Results: While many clinical findings and levels of all eight novel biomarkers were found to be significant predictors of outcome, none could be used individually to confirm or exclude ACS in the ED. We derived a nine-point CDR that combined clinical findings with biomarker levels to effectively stratify patients into four risk groups. 14.2% of patients were identified as being at ‘no risk’ and had a 0.0% outcome rate. The rule performed significantly better than two commonly used risk scores and may improve on triage decisions made in actual clinical practice. Conclusion: ACS remains a difficult diagnosis to confidently confirm or refute in the ED. Our CDR may help to avoid unnecessary hospital admissions while improving on triage decisions made for the remaining in-patients. Prospective validation of our findings is warranted.
43

Optimized approach to decision fusion of heterogeneous data for breast cancer diagnosis.

Jesneck, JL, Nolte, LW, Baker, JA, Floyd, CE, Lo, JY 08 1900 (has links)
As more diagnostic testing options become available to physicians, it becomes more difficult to combine various types of medical information together in order to optimize the overall diagnosis. To improve diagnostic performance, here we introduce an approach to optimize a decision-fusion technique to combine heterogeneous information, such as from different modalities, feature categories, or institutions. For classifier comparison we used two performance metrics: The receiving operator characteristic (ROC) area under the curve [area under the ROC curve (AUC)] and the normalized partial area under the curve (pAUC). This study used four classifiers: Linear discriminant analysis (LDA), artificial neural network (ANN), and two variants of our decision-fusion technique, AUC-optimized (DF-A) and pAUC-optimized (DF-P) decision fusion. We applied each of these classifiers with 100-fold cross-validation to two heterogeneous breast cancer data sets: One of mass lesion features and a much more challenging one of microcalcification lesion features. For the calcification data set, DF-A outperformed the other classifiers in terms of AUC (p < 0.02) and achieved AUC=0.85 +/- 0.01. The DF-P surpassed the other classifiers in terms of pAUC (p < 0.01) and reached pAUC=0.38 +/- 0.02. For the mass data set, DF-A outperformed both the ANN and the LDA (p < 0.04) and achieved AUC=0.94 +/- 0.01. Although for this data set there were no statistically significant differences among the classifiers' pAUC values (pAUC=0.57 +/- 0.07 to 0.67 +/- 0.05, p > 0.10), the DF-P did significantly improve specificity versus the LDA at both 98% and 100% sensitivity (p < 0.04). In conclusion, decision fusion directly optimized clinically significant performance measures, such as AUC and pAUC, and sometimes outperformed two well-known machine-learning techniques when applied to two different breast cancer data sets. / Dissertation
44

Functional evolution of mammalian odorant receptors.

Adipietro, KA, Mainland, JD, Matsunami, H January 2012 (has links)
The mammalian odorant receptor (OR) repertoire is an attractive model to study evolution, because ORs have been subjected to rapid evolution between species, presumably caused by changes of the olfactory system to adapt to the environment. However, functional assessment of ORs in related species remains largely untested. Here we investigated the functional properties of primate and rodent ORs to determine how well evolutionary distance predicts functional characteristics. Using human and mouse ORs with previously identified ligands, we cloned 18 OR orthologs from chimpanzee and rhesus macaque and 17 mouse-rat orthologous pairs that are broadly representative of the OR repertoire. We functionally characterized the in vitro responses of ORs to a wide panel of odors and found similar ligand selectivity but dramatic differences in response magnitude. 87% of human-primate orthologs and 94% of mouse-rat orthologs showed differences in receptor potency (EC50) and/or efficacy (dynamic range) to an individual ligand. Notably dN/dS ratio, an indication of selective pressure during evolution, does not predict functional similarities between orthologs. Additionally, we found that orthologs responded to a common ligand 82% of the time, while human OR paralogs of the same subfamily responded to the common ligand only 33% of the time. Our results suggest that, while OR orthologs tend to show conserved ligand selectivity, their potency and/or efficacy dynamically change during evolution, even in closely related species. These functional changes in orthologs provide a platform for examining how the evolution of ORs can meet species-specific demands. / Dissertation
45

Avaliação da sensibilidade cutânea em pés de pacientes diabéticos através do Pressure Specified Sensory Device TM / Evaluation of cutaneous sensibility threshold on the feet of diabetic patients with the Pressure Specified Sensory Device(TM)

Carvalho, Viviane Fernandes de 04 March 2008 (has links)
A neuropatia diabética causa diminuição ou perda da sensibilidade protetora do pé, tornando-o mais vulnerável ao trauma mecânico e térmico. A profilaxia das complicações neuropáticas tem início pela identificação da perda de sensibilidade e, portanto, do comprometimento neurológico. O Pressure Specified Sensory Device(TM) (PSSD) é um equipamento desenvolvido para quantificar o limiar de pressão, aplicada sobre a pele, necessária para que o paciente perceba o estímulo provocado por: um ponto estático, um ponto em movimento, dois pontos estáticos e dois pontos em movimento. Denominamos grupo estudo, aos trinta e quatro pacientes diabéticos do tipo 2, sem história prévia de feridas e/ou amputações nos pés que foram submetidos à avaliação de sensibilidade cutânea utilizando-se o PSSD(TM). Foram realizados testes nos territórios cutâneos dos nervos fibular profundo, plantar medial e ramo calcâneo do nervo tibial posterior. Estímulos foram provocados segundo as modalidades: um ponto estático (1 PE), um ponto em movimento (1 PD), dois pontos estáticos (2 PE) e dois pontos em movimento (2 PD), para as duas últimas modalidades. Previamente às modalidades 2PE e 2PD determinou-se o limiar de discriminação entre dois pontos estáticos (D2PE) e em movimento (D2PD). Foram realizados apenas no grupo estudo, testes com o monofilamento de Semmes-Weisntein nº 5,07 (MSW) e com o diapasão de 128 Hz. Vinte e oito pacientes não-diabéticos, submetidos aos mesmos testes, formaram o grupo controle. Para os limiares de sensibilidade, encontramos valores superiores no grupo estudo (p < 0,05). Ao compararmos os limiares de sensibilidade alcançados pelos pacientes diabéticos sensíveis e não sensíveis ao estímulo promovido pelo MSW nº 5,07 verificamos que o p-valor variou entre 0,018 < p < 0,113 para 1 PE e 0,002 < p < 0,083 para 2 PE, conforme o território cutâneo estudado. Na comparação dos limiares de sensibilidade da modalidade 1 PD entre diabéticos sensíveis e insensíveis à vibração do diapasão de 128 Hz, as diferenças não foram estatisticamente significantes (p = 0,183). Os resultados obtidos nos permitiram sugerir que o dispositivo PSSD(TM) seja utilizado como forma de acompanhamento do comprometimento da fibra nervosa. / Neuropathy is a severe progressive loss of protective sensation on the feet, making the patient more vulnerable to mechanical trauma and consequently more suitable to the development of chronic wounds, major distortion of the foot bone architecture and eventually to limb amputation. Prophylaxis should be enforced to avoid foot ulceration and for that, evaluation of the degree of loss of sensation on the skin is essential. The PSSD (Pressure Specified Sensory Device(TM)) was developed in order to quantify the threshold of pressure applied to the skin that could be recognized as positive by the patient. Pressure of one or two points is tested both statically and with movement, thus assessing the function of fast and slow response nerve fibers. Threshold of two-point discrimination was also measured in mm. Thirty four (n = 34) diabetic patients, type II, with no previous history of wounds on the lower extremity were studied using the tests, one point static (1PE), one point moving (1PD) and two points static (2 PE), and moving (2 PD) on the cutaneous territory of the fibular nerve and posterior tibial nerve (two territories - medial plantar and calcaneous nerves). The control group (28 non diabetic patients) was assessed by the same exams and the results were compared. In the diabetic group the cutaneous territories were also evaluated using the conventional Semmes-Weinstein filament nº 5,07 e vibrometer of the 128 Hz. Altered values were observed for the static and dynamic tests over the three studied nerve territories. The differences were statically significant (p < 0,05). Comparing the threshold of sensibility between sensitive and non sensitive diabetic patients to MSW nº 5,07 test, we observed that p-value range was 0,018 0,113 when 1PE test was applied, and 0,002 0,083 when 2PE test was applied, according to the cutaneous territories evaluated. Numeric quantification of the threshold of pressure allows us to determine the status of the fiber/receptor structures as well as the functional deficit of nerve fibers. Our findings suggest that PSSD(TM) is an adjuvant tool to evaluate the degree of loss of sensation on the skin.
46

A escala de avaliação de demência (DRS) no diagnóstico de comprometimento cognitivo leve e doença de Alzheimer / The dementia rating scale (DRS) in the diagnosis of mild cognitive impairment and Alzheimer´s disease

Porto, Claudia Sellitto 14 September 2006 (has links)
A Escala de Avaliação de Demência (Dementia Rating Scale -DRS), proposta por Steven Mattis (1988), tem sido bastante utilizada na avaliação de pacientes com demência tanto na atividade clínica como na pesquisa. Consiste de 5 subescalas: Atenção, Iniciativa/Perseveração, Construção, Conceituação e Memória. Neste estudo, a Escala de Avaliação de Demência foi aplicada em 56 pacientes com doença de Alzheimer com demência de intensidade leve; 55 pacientes com diagnóstico de comprometimento cognitivo leve; e, 60 indivíduos controles. Na diferenciação entre pacientes com doença de Alzheimer e controles a nota de corte de < 128 demonstrou 90,0% de sensibilidade e 89,3 % de especificidade; e, entre pacientes com doença de Alzheimer e comprometimento cognitivo leve, a nota de corte foi < 123 com sensibilidade de 78,2% e 76,8% de especificidade. Na diferenciação entre pacientes com comprometimento cognitivo leve e controles, a nota de corte foi de < 134 com 73,3% de sensibilidade e 72,7% de especificidade. A DRS demonstrou ser um instrumento com boa acurácia diagnóstica na discriminação entre pacientes com doença de Alzheimer de intensidade leve e indivíduos controles. A DRS também foi capaz de diferenciar entre pacientes com comprometimento cognitivo leve de controles, e pacientes com comprometiemnto cognitivo leve de pacientes com doença de Alzheimer de intensidade leve. As subescalas Memória e Iniciativa/Perseveração demonstraram maior acurácia diagnóstica em todas as situações analisadas quando comparadas às demais subescalas. / The Dementia Rating Scale (DRS), proposed by Steven Mattis (1988), it has been very used to assess patients with dementia both in clinical practice and research. Consists of 5 subscales: Attention, Initiation/Perseveration, Construction, Conceptualization and Memory. The Dementia Rating Scale was applied to 56 patients with Alzheimer´s disease, witha dementia of mild intensity; 55 patients with diagnosis of mild cognitive impairment; and, 60 controls. Between patients with Alzheimer´s disease and controls the cutoff score of <128 showed a 90.0% of sensitivity and 89.3% of specificity; and, between patients with Alzheimer´s disease and mild cognitive impairment, the cutoff score was <123 with sensitivity of 78.2% e 76.8% of specificity. In the analysis between patients with mild cognitive impairment and controls, the cutoff score was <134 with 73.3% of sensitivity and 72.7% of specificity. The Dementia Rating Scale showed to be a instrument with good diagnostic accuracy in the discrimination between patients with mild Alzheimer´s disease and controls. The Dementia Rating Scale also was able to discriminated between patients mild cognitive impairment and controls, and between patients with mild cognitive impairment and mild Alzheimer´s disease. The Memory and Initiation/Perseveration subscales showed good diagnostic accuracy in all analysed situations.
47

Colangiopancreatografia retrógrada endoscópica versus ultrassom endoscópico no diagnóstico histológico da estenose biliar maligna: revisão sistemática e metanálise / ERCP versus EUS for tissue diagnosis of malignant biliary stricture: systematic review and meta-analysis

Moura, Diogo Turiani Hourneaux de 07 March 2016 (has links)
Introdução: O diagnóstico histológico das estenoses biliares é fundamental na definição da terapêutica a ser empregada, devido à heterogeneidade dos resultados dos estudos comparando o uso do escovado citológico e da biópsia transpapilar na colangiopancreatografia retrógada endoscópica (CPRE) com a punção aspirativa ecoguiada com agulha fina (ECO-PAAF) no diagnóstico histológico da estenose biliar maligna, e o fato de não existirem revisões sistemáticas e metanálises comparando esses métodos, este estudo propõe comparar esses dois métodos no diagnóstico histológico da estenose biliar maligna, através de revisão sistemática e metanálise da literatura. Métodos: Utilizando as bases de dados eletrônicas Medline, Embase, Cochrane, LILACS, CINAHL, e Scopus foram pesquisados estudos datados anteriormente a novembro de 2014. De um total de 1009 estudos publicados, foram selecionados três estudos prospectivos comparando ECO-PAAF e CPRE no diagnóstico histológico da estenose biliar maligna e cinco estudos transversais comparando ECO-PAAF com o mesmo padrão-ouro dos outros três estudos comparativos. Todos os pacientes foram submetidos ao mesmo padrão-ouro. Foram calculadas as variáveis do estudo (prevalência, sensibilidade, especificidade, valores preditivos positivos e negativos e acurácia) e realizada a metanálise utilizando os softwares Rev Man 5 e Meta-DiSc 1.4. Resultados: Um total de 294 pacientes foi incluído na análise. A probabilidade pré-teste para estenose biliar maligna foi de 76,66%. As sensibilidades médias da CPRE e da ECO-PAAF para o diagnóstico histológico da estenose biliar maligna foram de 49% e 76,5%, respectivamente; especificidades foram de 96,33% e 100%, respectivamente. As probabilidades pós-teste também foram determinadas: valores preditivos positivos de 98,33% e 100%, respectivamente, e valores preditivos negativos de 34% e 58,87%. As acurácias foram 60,66% e 82,25%, respectivamente. Conclusão: A ECO-PAAF é superior a CPRE com escovado citológico e/ou biópsia transpapilar no diagnóstico histológico da estenose biliar maligna. No entanto, um teste de ECO-PAAF ou CPRE com amostra histológica negativa não pode excluir a estenose biliar maligna, pois ambos os testes apresentam baixo valor preditivo negativo / Background and Aims: Due the heterogeneity of the results of studies comparing the use of ERCP-based brush cytology and forceps biopsy and EUS-guided fine-needle aspiration for the diagnosis of malignant biliary stricture, and the fact that there are no systematic reviews and meta-analysis comparing these methods, in this review, we will compare ERCP against EUS-FNA for tissue diagnosis of malignant biliary stricture. Design: A systematic review of comparative studies (prospective or retrospective) was conducted analyzing EUS and ERCP for tissue diagnosis of malignant biliary stricture. Methods: The databases Medline, EMBASE, Cochrane, LILACS, CINAHL, and Scopus were searched for studies dated previous to November 2014. We identified three prospective studies comparing EUS-FNA and ERCP for the diagnosis of malignant biliary stricture and five cross sectional studies comparing EUS-FNA with the same gold standard of the other three studies. All patients were submitted to the same gold standard method. We calculated study variables (prevalence, sensitivity, specificity, positive and negative predictive values, and accuracy) and performed a meta-analysis using the Rev Man 5 and Meta-DiSc 1.4 softwares. Results: A total of 294 patients were included in the analysis. The pretest probability for malignant biliary stricture was 76.66%. The mean sensitivities of ERCP and EUS-FNA for tissue diagnosis of malignant biliary stricture were 49% and 76.5%, respectively; specificities were 96.33% and 100%, respectively. The post-test probabilities, positive predictive value (98.33% and 100%, respectively) and negative predictive value (34% and 58.87%, respectively) were determined. The accuracies were 60.66% and 82.25%, respectively. Conclusion: EUS- FNA is superior to ERCP with brush cytology and forceps biopsy for diagnosing malignant biliary strictures. However, a negative EUS-FNA or ERCP test may not exclude malignant biliary stricture because both have low negative post-test probabilities
48

Predição da restrição do crescimento fetal pela medida da altura uterina / Prediction of fetal growth restriction by uterine height

Martinelli, Silvio 08 March 2004 (has links)
O objetivo deste estudo foi verificar o poder de predição da medida da altura uterina para a restrição do crescimento fetal (RCF), por meio da curva de MARTINELLI et al. (2001), tendo como limite o percentil 5 e 10 para a idade gestacional e comparar com a curva de BELIZÁN et al. (1978). Entre julho de 2000 e fevereiro de 2003, 238 gestantes de alto risco foram submetidas a medidas de altura uterina, da 20a à 42a semana de gestação. Todas possuíam idade gestacional confirmada por ultra-sonografia precoce. A confirmação do diagnóstico de RCF foi dada após o nascimento pela curva de RAMOS (1983). Entre as gestantes, 50 (21,0%) tiveram recém-nascidos pequenos para a idade gestacional. O mesmo observador realizou 1617 medidas de altura uterina, com fita métrica, da borda superior da sínfise púbica ao fundo uterino. Para a ocorrência de RCF, considerando um exame positivo se uma medida de altura uterina encontrava-se abaixo do percentil 10 para a idade gestacional na curva de MARTINELLI et al. (2001), a sensibilidade (S) foi de 78%, especificidade (E) de 77,1%, valor preditivo positivo (VPP) de 47,6% e valor preditivo negativo (VPN) de 92,9%. Utilizando como limite o percentil 5, foram obtidos S= 64%, E= 89,9%, VPP= 62,7% e VPN= 90,4%, para o diagnóstico da RCF. Utilizando-se a curva de BELIZÁN et al. (1978) e considerando positivo exame com um valor abaixo do percentil 10 para a idade gestacional, os resultados encontrados foram S= 54%, E= 97,3%, VPP= 84,4% e VPN= 88,8% para a identificação da RCF. Comparada à curva de BELIZÁN et al. (1978), a curva de altura uterina de MARTINELLI et al. (2001) apresentou maior sensibilidade e valor preditivo negativo, consistindo em método de triagem mais adequado para a RCF / The aim of this study was to correlate uterine height measurements below the 5th and 10th percentiles using MARTINELLI et al. (2001) curve to fetal growth restriction (FGR) and to compare with the BELIZÁN et al. (1978) curve. During the period of July 2000 and February 2003, 238 pregnant women of high risk were submitted to uterine height measurements between the 20th and 42nd weeks of gestation. The whole group had well-known gestational age, confirmed by early ultrasound. The diagnosis of FGR was confirmed after birth according to RAMOS (1983). Among these women, 50 (21,0%) gave birth to light for gestational age infants. The same observer, using tape measure, performed 1617 uterine height measurements, from the upper border of the symphysis pubis to the fundus uteri. For the diagnosis of FGR, being considered as positive the exam with measurements below the 10th percentile according to MARTINELLI et al. (2001) curve, the sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were 78,0%, 77,1%, 47,6% and 92,9%, respectively. For the 5th percentile, this curve showed SE= 64,0%, SP= 89,9%, PPV= 62,7% and NPV= 90,4% for the detection of FGR. The BELIZÁN et al. (1978) curve, having the 10th percentile as the limit, yielded SE= 54,0%, SP= 97,3%, PPV= 84,4% and NPV= 88,8% for the identification of FGR. We conclude that, when used for screening FGR, the MARTINELLI et al. (2001) curve showed greater sensitivity and negative predictive value, and presents better results than that of Belizán et al. (1978)
49

Sensibilidade e especificidade do Sistema Manchester de Classificação de Risco na priorização de pacientes com infarto agudo do miocárdio que apresentam dor torácica / Sensitivity and specificity of Manchester Triage System in the prioritization of patients with acute myocardial infarction who present chest pain.

Nishi, Fernanda Ayache 09 June 2017 (has links)
Introdução: O Sistema Manchester de Classificação de Risco tem como objetivo definir a prioridade clínica para atendimento médico de pacientes nos serviços de emergência. A avaliação de pacientes com suspeita de infarto agudo do miocárdio com sintomas típicos como a dor torácica realizada por meio do Sistema Manchester exige adequada sensibilidade e especificidade do sistema ao determinar a prioridade para atendimento médico. Objetivos: Os objetivos deste estudo foram integrar as melhores evidências disponíveis quanto a sensibilidade e especificidade do Sistema Manchester na classificação de pacientes com relação ao diagnóstico de síndrome coronariana aguda; estimar a sensibilidade e especificidade do Sistema Manchester na classificação de pacientes com dor torácica para a adequada priorização no que se refere ao diagnóstico de infarto agudo do miocárdio num hospital geral de ensino na cidade de São Paulo; e verificar associação entre o desempenho do Sistema Manchester na avaliação desses pacientes e variáveis selecionadas. Método: Este estudo foi desenvolvido em duas etapas, sendo a primeira uma revisão sistemática da literatura realizada segundo metodologia de revisões de acurácia de testes diagnósticos do Joanna Briggs Institute. Na segunda etapa do estudo foram estimadas a sensibilidade e a especificidade do Sistema Manchester na avaliação de pacientes com infarto agudo do miocárdio por meio de um estudo metodológico, transversal e retrospectivo. A sensibilidade e a especificidade do Sistema Manchester foram estimadas por meio da verificação da classificação estabelecida para pacientes com dor torácica que receberam ou não o diagnóstico médico de infarto agudo do miocárdio após a classificação. Resultados: Foram incluídos na revisão sistemática seis estudos com total de 54.176 participantes, todos de qualidade metodológica moderada, que apontaram valores de sensibilidade entre 70% e 80%. Dois estudos que apresentaram os dados necessários para o cálculo de especificidade, tiveram valores calculados de 59% e 97%. A amostra do estudo primário incluiu 10.087 episódios de classificação, sendo 52,3% de pacientes do sexo feminino com média de idade de 43,6 anos (DP=17,6). Do total de episódios, 139 tinham diagnóstico de infarto. A sensibilidade do Sistema Manchester foi de 44,6% e a especificidade foi de 91,3%. Houve associação estatisticamente significativa entre o desempenho do Sistema Manchester e a idade dos pacientes (p<0,001), com maior frequência de classificação incorreta nas faixas etárias mais altas. Não houve associação entre o sexo dos pacientes e o desempenho do Sistema Manchester. Conclusão: a recomendação para uso do Sistema Manchester na avaliação de pacientes no serviço de urgência em relação ao diagnóstico de síndrome coronariana aguda foi de grau B segundo graus de recomendação estabelecidos pelo Joanna Briggs Institute, o que remete a uma recomendação \"fraca\" para uma determinada estratégia de gestão da saúde. Essa conclusão decorre sobretudo da heterogeneidade dos critérios de inclusão e portanto das amostras dos estudos incluídos. Os resultados do estudo evidenciam a necessidade de se discutir formas de melhorar a sensibilidade desse sistema para a adequada priorização de pacientes com dor torácica. / Introduction: The Manchester Triage System aims to define the clinical priority of patients for medical care in the emergency department. The evaluation of patients with suspected acute myocardial infarction presenting typical symptoms such as chest pain using the Manchester Triage System requires proper sensitivity and specificity of the system in order to determine medical care priority. Objectives: The objectives of this study were: to integrate the best available evidence regarding the sensitivity and specificity of the Manchester Triage System in the evaluation of patients with the diagnose of acute coronary syndrome; to estimate the sensitivity and specificity of the Manchester Triage System in the classification of patients with chest pain to adequate prioritization in relation to the diagnose of acute myocardial infarction in a general teaching hospital in the city of São Paulo; to verify the association between the performance of the Manchester Triage System in the evaluation of these patients and selected variables. Methods: This study was developed in two stages, the first one consisted in a systematic review performed according to the methodology of diagnostic test accuracy systematic reviews from Joanna Briggs Institute. In the second stage of the study the sensitivity and specificity of the Manchester Triage System in the evaluation of patients with acute myocardial infarction were estimated though a methodological retrospective cross-sectional study. The sensitivity and specificity of the Manchester Triage System were estimated by verifying the classification of patients with chest pain who received or not the medical diagnosis of acute myocardial infarction. Results: The systematic review included six studies with a total of 54,176 participants, all of the studies with moderate methodological quality. The studies pointed sensitivity values from 70% to 80%. The specificity values calculated from two studies containing the necessary data were 59% and 97%. The sample of the performed primary study included 10,087 episodes of classification, 52.3% of the patients were females with average age of 43.58 years (SD=17.6). Of the total episodes, 139 had the diagnosis of infarction. The sensitivity of the Manchester Triage System was 44.6% and the specificity was 91.3%. There was statistically significant association between the performance of the Manchester Triage System and the age of the patients (p<0.001), with a higher frequency of incorrect classification in the older age groups. There was no observed association between the sex of the patients and the performance of the Manchester Triage System. Conclusion: Recommendation for the utilization of the Manchester Triage System in the evaluation of patients in emergency services to correct prioritization related to the diagnose of acute coronary syndrome was graded B according to the Joanna Briggs Institute grades of recommendation, which refers to a weak recommendation to a certain strategy for healthcare management. This finding is due to the heterogeneity of the inclusion criteria and therefore the samples of the included studies. The results of this study highlight the necessity of discussion about ways to improve the sensitivity of this system, for the adequate prioritization of patients with chest pain.
50

Acurácia da ressonância magnética na detecção de roturas e de instabilidade na porção intra-articular do tendão da cabeça longa do bíceps braquial em pacientes submetidos a reparo do manguito rotador / Accuracy of magnetic resonance imaging in the detection of tears and instability in the intra-articular portion of the long head of biceps tendon in patients undergoing rotator cuff repair

Baptista, Eduardo 05 February 2019 (has links)
A literatura a respeito da capacidade da ressonância magnética em avaliar as afecções do tendão da cabeça longa do bíceps é escassa, a despeito da importância destas condições na gênese da dor e da disfunção do ombro. O objetivo primário deste estudo foi analisar o desempenho diagnóstico da ressonância magnética na detecção de roturas e de instabilidade na porção intra-articular deste tendão, comparando os achados de imagem com os dados de cirurgia artroscópica (padrão de referência). Foram objetivos secundários determinar as reprodutibilidades intraobservador e interobservador, avaliar a capacidade da ressonância magnética em classificar os tipos de rotura, avaliar a acurácia da associação entre alterações tendíneas e roturas do manguito rotador na instabilidade, além de pesquisar fatores preditores da acurácia da ressonância magnética. Foi realizado estudo transversal, com segmentos retrospectivo e prospectivo. Os critérios de inclusão foram indicação de cirurgia artroscópica do ombro para reparo do manguito rotador e exame de ressonância magnética préoperatória. Os critérios de exclusão foram: manipulação cirúrgica pregressa no ombro estudado; exames com imagens de má qualidade; intervalo entre exame pré-operatório e procedimento cirúrgico superior a um ano; indicação de técnica cirúrgica por via aberta. Foram estudados 100 ombros de 98 pacientes, operados consecutivamente de abril de 2013 a março de 2017 (47 meses). Todos os pacientes realizaram ressonância magnética de 1,5 Tesla em nossa instituição, sem utilização de contraste intra-articular. Todas as cirurgias foram realizadas pelos mesmos 3 cirurgiões, com 10 a 12 anos de experiência em cirurgia do ombro e cotovelo. Dois radiologistas, com 4 e 8 anos de experiência na área musculoesquelética, avaliaram as imagens de todos os exames, de forma independente e sem conhecimento prévio dos resultados intra-operatórios. Os mesmos casos foram revistos por um dos radiologistas, 4 meses após a primeira análise. Nossos resultados demostraram desempenho diagnóstico moderado da ressonância magnética para detecção de roturas do bíceps, com sensibilidades entre 71,1% a 73,3%, especificidades de 72,7% e acurácia entre 72 e 73%. A reprodutibilidade interobservador foi substancial (coeficiente Kappa de 0,62 a 0,69) e a reprodutibilidade intraobservador foi substancial ou quase perfeita na avaliação das roturas (coeficiente Kappa de 0,74 a 0,82). Houve correlação moderada entre os métodos para classificar o tipo de rotura (coeficiente Kappa de 0,38 a 0,47). Quando consideradas roturas completas, foram calculadas especificidades entre 75,0% e 95,7%, porém sensibilidades de 55,6% a 66,7%. Para o diagnóstico de instabilidade, observa-se sensibilidade de 52,4% a 59,1%, especificidade de 70,5% a 84% e acurácia de 64,4% a 69,5%. A avaliação combinada do deslocamento tendíneo e das roturas do manguito rotador resultou em sensibilidades de 17,5% a 47,7% e especificidades de 72,7% a 90,7%. A reprodutibilidade interobservador foi substancial (coeficiente Kappa de 0,59 a 0,7) e a reprodutibilidade intraobservador foi substancial ou quase perfeita (coeficiente Kappa de 0,76 a 0,80) para avaliação de instabilidade. Não identificamos fatores preditores para acurácia da ressonância magnética na pesquisa dessas afecções / There is paucity of literature regarding the performance of magnetic resonance imaging to assess long head of the biceps tendon disorders, despite the importance of such disorders in the genesis of pain and shoulder dysfunction. The primary objective of this study was to analyze the diagnostic performance of magnetic resonance imaging in the detection of tears and instability of the intra-articular portion of this tendon, comparing imaging findings with data from arthroscopic surgery (reference standard). Secondary objectives were to determine intraobserver and interobserver reproducibility; to evaluate the capability of MRI to classify types of tears; to evaluate the accuracy of the association between tendon displacement and rotator cuff tears to predict instability; to investigate predictive factors of magnetic resonance accuracy. A cross-sectional study was carried out, with retrospective and prospective segments. Inclusion criteria were indication of arthroscopic shoulder surgery for rotator cuff repair and preoperative magnetic resonance imaging. Exclusion criteria were: previous surgical manipulation in the studied shoulder; poor quality images; interval between preoperative examination and surgical procedure above one year; and indication of open surgical technique. We studied 100 shoulders of 98 consecutively operated patients from April 2013 to March 2017 (47 months). All patients underwent magnetic resonance imaging at our institution, using a 1.5 Tesla scanner, without use of intra-articular contrast. All surgeries were performed by the same 3 surgeons, with 10 to 12 years of experience in shoulder and elbow surgery. Two radiologists, with 4 and 8 years of experience in musculoskeletal radiology, evaluated the images independently and without previous knowledge of the intraoperative results. The same cases were reviewed by one of the radiologists, 4 months after the first analysis. Our results demonstrated a moderate diagnostic performance of MRI to detect biceps tears, with sensitivities between 71.1% and 73.3%, specificities of 72.7% and accuracy between 72 and 73%. Interobserver reproducibility was substantial (Kappa coefficient ranged from 0.62 to 0.69), and intraobserver reproducibility was substantial or almost perfect (Kappa coefficient ranged from 0.74 to 0.82). There was moderate correlation between the methods when classifying the type of tear (Kappa coefficient ranged from 0.38 to 0.47). Regarding full-thickness tears, specificities were calculated between 75.0% and 95.7%, but sensitivities from 55.6% to 66.7%. For the diagnosis of instability, sensitivity was from 52.4% to 59.1%, specificity was from 70.5% to 84% and accuracy was from 64,4% to 69,5%. The combined evaluation of tendon displacement and rotator cuff tears resulted in sensitivities from 17.5% to 47.7% and specificities from 72.7% to 90.7%. Interobserver reproducibility was substantial (Kappa coefficient ranged from 0.59 to 0.7), and intraobserver reproducibility was substantial or almost perfect (Kappa coefficient ranged from 0.76 to 0.80) for instability assessment. We did not identify predictive factors for magnetic resonance imaging accuracy in the assessment of these conditions

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