Rational use of diagnostic tests for clinical decision making.

OBJECTIVE: To assist clinicians to make adequate interpretation of scientific evidence from studies that evaluate diagnostic tests in order to allow their rational use in clinical practice. METHODS: This is a narrative review focused on the main concepts, study designs, the adequate interpretation of the diagnostic accuracy data, and making inferences about the impact of diagnostic testing in clinical practice. RESULTS: Most of the literature that evaluates the performance of diagnostic tests uses cross-sectional design. Randomized clinical trials, in which diagnostic strategies are compared, are scarce. Cross-sectional studies measure diagnostic accuracy outcomes that are considered indirect and insufficient to define the real benefit for patients. Among the accuracy outcomes, the positive and negative likelihood ratios are the most useful for clinical management. Variations in the study's cross-sectional design, which may add bias to the results, as well as other domains that contribute to decreasing the reliability of the findings, are discussed, as well as how to extrapolate such accuracy findings on impact and consequences considered important for the patient. Aspects of costs, time to obtain results, patients' preferences and values should preferably be considered in decision making. CONCLUSION: Knowing the methodology of diagnostic accuracy studies is fundamental, but not sufficient, for the rational use of diagnostic tests. There is a need to balance the desirable and undesirable consequences of tests results for the patients in order to favor a rational decision-making approach about which tests should be recommended in clinical practice.

Rational use of diagnostic tests for clinical decision making

SUMMARY OBJECTIVE: To assist clinicians to make adequate interpretation of scientific evidence from studies that evaluate diagnostic tests in order to allow their rational use in clinical practice. METHODS: This is a narrative review focused on the main concepts, study designs, the adequate interpretation of the diagnostic accuracy data, and making inferences about the impact of diagnostic testing in clinical practice. RESULTS: Most of the literature that evaluates the performance of diagnostic tests uses cross-sectional design. Randomized clinical trials, in which diagnostic strategies are compared, are scarce. Cross-sectional studies measure diagnostic accuracy outcomes that are considered indirect and insufficient to define the real benefit for patients. Among the accuracy outcomes, the positive and negative likelihood ratios are the most useful for clinical management. Variations in the study's cross-sectional design, which may add bias to the results, as well as other domains that contribute to decreasing the reliability of the findings, are discussed, as well as how to extrapolate such accuracy findings on impact and consequences considered important for the patient. Aspects of costs, time to obtain results, patients' preferences and values should preferably be considered in decision making. CONCLUSION: Knowing the methodology of diagnostic accuracy studies is fundamental, but not sufficient, for the rational use of diagnostic tests. There is a need to balance the desirable and undesirable consequences of tests results for the patients in order to favor a rational decision-making approach about which tests should be recommended in clinical practice.

RESUMO OBJETIVO: Auxiliar os clínicos na interpretação adequada das evidências científicas de estudos que avaliam testes diagnósticos, de modo a permitir seu uso racional na prática clínica. MÉTODOS: Revisão narrativa da literatura dos principais conceitos, desenhos de estudo, interpretação adequada dos dados de acurácia diagnóstica e realização de inferências sobre o impacto do teste diagnóstico na prática clínica. RESULTADOS: A maioria da literatura que avalia o desempenho de testes diagnósticos utiliza como delineamento os estudos transversais. Ensaios clínicos randomizados, avaliando desfechos clínicos, que seriam considerados ideais, são escassos. Os estudos transversais mensuram desfechos de acurácia diagnóstica que são considerados indiretos e insuficientes para definir o real benefício para os pacientes. Dentre os desfechos, as razões de verossimilhança positiva e negativa são as mais úteis para a decisão da conduta clínica. Variações no delineamento transversal do estudo, que podem acrescentar vieses aos resultados, bem como outros domínios que contribuem para diminuir a confiabilidade dos achados, são discutidos, além de como extrapolar tais achados de acurácia em impacto e consequências consideradas importantes para o paciente. Aspectos sobre custos, tempo para a obtenção do resultado, preferências e valores dos pacientes devem, preferencialmente, participar da tomada de decisão. CONCLUSÃO: Conhecer a metodologia dos estudos de acurácia diagnóstica é fundamental, porém não suficiente, para o uso racional de testes diagnósticos. Há a necessidade de se ponderarem as consequências desejáveis e indesejáveis dos resultados dos testes para os pacientes, de modo a favorecer a tomada de decisão racional acerca de qual teste recomendar na prática clínica.

Prevalence and risk factors for stroke in a population of Southern Brazil.

UNLABELLED: Stroke is the leading cause of death in many countries of Latin America. Population studies are necessary in this region. OBJECTIVES: To evaluate the prevalence of stroke and its risk factors in a population of vulnerable communities of southern Brazil. METHODS: Population-based crosssectional study with systematic sampling. Individuals aged 20 and over were included (n=3,391). Individuals with previous diagnosis of stroke or identified by a validate stroke questionnaire were compared with those without stroke in many variables. RESULTS: 285 individuals (8.4%) had previous stroke. The group without stroke showed greater average of years of study than the group with stroke (p<0.001). Multivariable analysis identified as risk factors for stroke (p<0.05): age from 40 to 59, age from 60 to 79, widowhood, present smoking, previous smoking, hypertension and ischemic heart disease. CONCLUSION: The findings in this population indicate the need of preventive cost-effective public health policies in Brazil.

Prevalence and risk factors for stroke in a population of Southern Brazil / Prevalência e fatores de risco para AVC numa população do sul do Brasil

Stroke is the leading cause of death in many countries of Latin America. Population studies are necessary in this region. Objectives: To evaluate the prevalence of stroke and its risk factors in a population of vulnerable communities of southern Brazil. Methods: Population-based crosssectional study with systematic sampling. Individuals aged 20 and over were included (n=3,391). Individuals with previous diagnosis of stroke or identified by a validate stroke questionnaire were compared with those without stroke in many variables. Results: 285 individuals (8.4%) had previous stroke. The group without stroke showed greater average of years of study than the group with stroke (p≪0.001). Multivariable analysis identified as risk factors for stroke (p≪0.05): age from 40 to 59, age from 60 to 79, widowhood, present smoking, previous smoking, hypertension and ischemic heart disease. Conclusion: The findings in this population indicate the need of preventive cost-effective public health policies in Brazil. .

O acidente vascular cerebral (AVC) é a principal causa de morte em muitos países da América Latina. Objetivos: Avaliar prevalência e fatores de risco para AVC em população de comunidades vulneráveis no sul do Brasil. Métodos: Estudo transversal de base populacional com amostragem sistemática. Foram incluídos os indivíduos a partir de 20 anos de idade (n=3.391). Indivíduos com prévio diagnóstico de AVC ou identificados por questionário validado para AVC foram comparados àqueles sem AVC em diversas variáveis. Resultados: 285 indivíduos (8,4%) referiram AVC prévio. O grupo sem AVC teve maior média de anos de estudo que o grupo com AVC (p≪0,001). Foram identificados como fatores de risco para AVC (p≪0,05): idade de 40 a 59 anos, idade de 60 a 79 anos, viuvez, tabagismo no presente, tabagismo no passado, hipertensão arterial sistêmica e doença isquêmica do coração. Conclusão: São necessárias no Brasil políticas de saúde pública preventivas e custo-efetivas. .

Guidelines for acute ischemic stroke treatment: part II: stroke treatment.

The second part of these Guidelines covers the topics of antiplatelet, anticoagulant, and statin therapy in acute ischemic stroke, reperfusion therapy, and classification of Stroke Centers. Information on the classes and levels of evidence used in this guideline is provided in Part I. A translated version of the Guidelines is available from the Brazilian Stroke Society website (www.sbdcv.com.br).

Guidelines for acute ischemic stroke treatment: part II: stroke treatment / Diretrizes para o tratamento do acidente vascular cerebral isquêmico: parte II: tratamento do acidente vascular

The second part of these Guidelines covers the topics of antiplatelet, anticoagulant, and statin therapy in acute ischemic stroke, reperfusion therapy, and classification of Stroke Centers. Information on the classes and levels of evidence used in this guideline is provided in Part I. A translated version of the Guidelines is available from the Brazilian Stroke Society website (www.sbdcv.com.br).

A segunda parte das Diretrizes aborda os tópicos de antiagregantes plaquetários, anticoagulantes e terapia de reperfusão para acidente vascular cerebral (AVC) isquêmico. Os critérios para nível de evidência e graus de recomendação estão contidos na primeira parte do documento. Uma versão traduzida destas Diretrizes encontra-se publicada no portal da Sociedade Brasileira de Doenças Cerebrovasculares (www.sbdcv.org.br).

[Reliability of neurological assessment scales in patients with stroke]. / Confiabilidade de escalas de comprometimento neurológico em pacientes com acidente vascular cerebral.

Scales for the assessment of neurological impairment are employed in clinical trials, outcome evaluation and in therapeutic decisions. We evaluated the reliability of the Portuguese version of the Rankin Scale (RS), Barthel Index (BI) and the NIHSS (National Institute of Health Stroke Scale) in 51 stroke patients, estimating the agreement of the results for examiners. The interrater reliability was measured using the Kappa Coefficient and Intraclass Correlation Coefficient. The RS showed moderate, substantial and excellent coefficients of agreement. The BI showed from substantial to excellent coefficients of agreement as a whole and also for its constituents. This scale was stratified in prognostic and functional groups, both presenting coefficients of agreement from substantial to excellent. The NIHSS presented excellent agreement on its total and substantial agreements on its individual items. The NIHSS was also stratified in groups of points, which presented moderate or excellent coefficient, and in groups of congruous items, wich showed a moderate to excellent agreement. These results suggest that the Portuguese version of the RS, BI and the NIHSS present adequate reliability.

Confiabilidade de escalas de comprometimento neurológico em pacientes com acidente vascular cerebral / Reliability of neurological assessment scales in patients with stroke / Reliability of neurological assessment scales in patients with stroke

Escalas de comprometimento neurológico são utilizadas na avaliação de novos tratamentos, no acompanhamento da evolução clínica e em decisões terapêuticas. Estudamos a confiabilidade de três escalas: a Escala de Rankin (ER), o índice de Barthel (IB) e a National Institute of Health Stroke Scale (NIHSS) versadas em português, em 51 indivíduos com acidente vascular cerebral, estimando a concordância entre resultados de diferentes examinadores. Utilizamos os coeficientes de concordância Kappa e Coeficiente de Correlação Intraclasse. A ER teve coeficientes moderados, substanciais ou excelentes. No IB estes foram substanciais ou excelentes nos totais e nos itens, assim como quando foi estratificado em agrupamentos prognósticos e funcionais. A NIHSS apresentou coeficientes excelentes nos totais, substanciais nos itens e moderados e excelentes nas estratificações em grupos de pontos e de itens afins. Estes resultados indicam que as versões em português da ER, o IB e a NIHSS apresentam adequada confiabilidade.

Scales for the assessment of neurological impairment are employed in clinical trials, outcome evaluation and in therapeutic decisions. We evaluated the reliability of the Portuguese version of the Rankin Scale (RS), Barthel Index (BI) and the NIHSS (National Institute of Health Stroke Scale) in 51 stroke patients, estimating the agreement of the results for examiners. The interrater reliability was measured using the Kappa Coefficient and Intraclass Correlation Coefficient. The RS showed moderate, substantial and excellent coefficients of agreement. The BI showed from substantial to excellent coefficients of agreement as a whole and also for its constituents. This scale was stratified in prognostic and functional groups, both presenting coefficients of agreement from substantial to excellent. The NIHSS presented excellent agreement on its total and substantial agreements on its individual items. The NIHSS was also stratified in groups of points, which presented moderate or excellent coefficient, and in groups of congruous items, wich showed a moderate to excellent agreement. These results suggest that the Portuguese version of the RS, BI and the NIHSS present adequate reliability.

[Clinical and interventional revascularization in the acute ischemic stroke: national opinion]. / Revascularização clínica e intervencionista no acidente vascular cerebral isquêmico agudo: opinião nacional.

The Brazilian Stroke Society constituted a committee composed by specialists from different areas of Brazil that emitted a viewpoint called "National Opinion," considering the interventional procedures and thrombolysis in the treatment of the acute ischemic stroke. This study presents the conclusions of this committee.

Revascularização clínica e intervencionista no acidente vascular cerebral isquêmico agudo: opinião nacional / Clinical and interventional revascularization in the acute ischemic stroke: national opinion

Este artigo apresenta as conclusões sobre revascularização clínica e intervencionista no acidente vascular cerebral isquêmico agudo, um dos temas discutidos na reunião "Opinião Nacional sobre o Tratamento do AVC". Tratou-se de reunião promovida e coordenada pela Sociedade Brasileira de Doenças Cerebrovasculares, com neurologistas especializados em doenças cerebrovasculares, que analisaram e discutiram as evidências e experiências atuais sobre o uso de trombólise e técnicas intervencionistas em pacientes com acidente vascular cerebral isquêmico agudo.

Association between the effect of spontaneous contrast in the thoracic aorta and recent ischemic stroke determined by transesophageal echocardiography.

OBJECTIVE: To assess the independent association between the presence of spontaneous echo contrast in the aorta and recent stroke events. METHODS: Two hundred and twenty-four individuals with a diagnosis of recent stroke and 85 control individuals who were examined due to various present/suspected heart diseases were studied through transesophageal echocardiography. The effects of spontaneous contrast in the aorta and the presence of other potential sources of cardiac embolism associated with them were researched and a questionnaire was completed about patients' clinical risk factors at the time of examination. RESULTS: The effects of contrast in the aorta was associated with stroke (OR=2.83; CI = 95%, 1.65-4.46; P<0.001) in the bivariate analysis. In the multivariate analysis, it remained associated with recent stroke (OR=2.05; CI = 90%, 1.10-3.85; P=0.06). Age > 60 years, a history of systemic blood hypertension and smoking, and dyslipidemia were risk factors independently associated with the effects of contrast in the aorta. The presence of a spontaneous contrast effect in the left atrium and Lambl's excrescences were echocardiographic factors independently associated with the effects of contrast in the aorta. CONCLUSION: The effect of contrast in the aorta was independently associated with recent stroke and with its clinical risk factors. These results reinforce the hypothesis that the phenomenon is a predictor of several risk factors.

Associação entre o efeito de contraste espontâneo na aorta torácica e eventos isquêmicos encefálicos recentes. Estudo através do ecocardiograma transesofágico / Association between the effect of spontaneous contrast in the thoracic aorta and recent ischemic stroke determined by transesophageal echocardiography

OBJETIVO: Avaliar a existência de associação independente entre a presença de efeito de contraste espontâneo na aorta e eventos isquêmicos encefálicos recentes. MÉTODOS: Estudados com ecocardiograma transesofágico 224 indivíduos com diagnóstico de eventos isquêmicos encefálicos recente 5 e 85 controles que realizaram o exame por diversas doenças cardíacas presentes/suspeitas, sendo pesquisado a presença do efeito de contraste na aorta e de outras potenciais fontes emboligênicas cardíacas associadas. Um questionário sobre os fatores de risco clínicos para eventos isquêmicos encefálicos foi coletado no momento do exame. RESULTADOS: O efeito de contraste na aorta apresentou associação com eventos isquêmicos encefálicos (RC=2,83; IC 95 por cento, 1,65-4,46; P<0,001), na análise bivariada. Na análise multivariada, permaneceu associado a eventos isquêmicos encefálicos recentes (RC=2,05; IC 90 por cento, 1,10-3,85 ; P=0,06). A idade > 60 anos, história de hipertensão arterial sistêmica, história de tabagismo e de dislipidemia foram fatores de risco associados independentemente ao efeito de contraste na aorta. A presença de efeito de contraste espontâneo no átrio esquerdo e a de excrescências de Lambl foram fatores ecocardiográficos associados independentemente ao efeito de contraste na aorta. CONCLUSÃO: O efeito de contraste na aorta esteve associado, de forma independente, aos eventos isquêmicos encefálicos recentes, bem como seus fatores de risco clínicos. Estes resultados vêm reforçar a hipótese de que o fenômeno é um marcador de múltiplos fatores de risco.

Instrumentos utilizados para avaliar o estado funcional das pessoas com dor lombar / Instruments used to evaluate the people’s functional state with lumbar pain

O objetivo deste artigo é identificar os instrumentos que avaliam a funcionalidade de pessoas com dor lombar, verificar as mais utilizadas nesta área da saúde e o seu auxílio ao diagnóstico e manejo da lombalgia e lombociatalgia. O presente artigo é uma revisão bibliográfica não sistemática sobre a dor lombar e escalas de avaliação da funcionalidade. Muitas escalas estão sendo utilizadas para avaliar as alterações funcionais de pacientes com dor lombar, sendo que as mais utilizadas são as escalas de Roland Morris e de Oswestry. A importância dada ao estudo da dor lombar tem aumentado nos últimos anos, principalmente porque esta algia resulta em incapacidade para o trabalho e impede as pessoas que sofrem com ela de exercer as atividades diárias, conseqüentemente afetando a sua qualidade de vida. A avaliação da funcionalidade é um considerável método diagnóstico e parâmetro na triagem de pacientes com dor lombar para o tratamento conservador ou cirúrgico.