Is the Bland-Altman plot method useful without inferences for accuracy, precision, and agreement?

ABSTRACT OBJECTIVE This study aims to propose a comprehensive alternative to the Bland-Altman plot method, addressing its limitations and providing a statistical framework for evaluating the equivalences of measurement techniques. This involves introducing an innovative three-step approach for assessing accuracy, precision, and agreement between techniques, which enhances objectivity in equivalence assessment. Additionally, the development of an R package that is easy to use enables researchers to efficiently analyze and interpret technique equivalences. METHODS Inferential statistics support for equivalence between measurement techniques was proposed in three nested tests. These were based on structural regressions with the goal to assess the equivalence of structural means (accuracy), the equivalence of structural variances (precision), and concordance with the structural bisector line (agreement in measurements obtained from the same subject), using analytical methods and robust approach by bootstrapping. To promote better understanding, graphical outputs following Bland and Altman's principles were also implemented. RESULTS The performance of this method was shown and confronted by five data sets from previously published articles that used Bland and Altman's method. One case demonstrated strict equivalence, three cases showed partial equivalence, and one showed poor equivalence. The developed R package containing open codes and data are available for free and with installation instructions at Harvard Dataverse at https://doi.org/10.7910/DVN/AGJPZH. CONCLUSION Although easy to communicate, the widely cited and applied Bland and Altman plot method is often misinterpreted, since it lacks suitable inferential statistical support. Common alternatives, such as Pearson's correlation or ordinal least-square linear regression, also fail to locate the weakness of each measurement technique. It may be possible to test whether two techniques have full equivalence by preserving graphical communication, in accordance with Bland and Altman's principles, but also adding robust and suitable inferential statistics. Decomposing equivalence into three features (accuracy, precision, and agreement) helps to locate the sources of the problem when fixing a new technique.

Validez de apariencia y racionalidad de una metodología para estudiar la causalidad en salud / Appearance and rational validity of a methodology to study causality in health

Introducción: Es objetivo fundamental de la medicina, determinar las causas que producen las enfermedades; para llevar a cabo este estudio, a finales del siglo XX se emplearon técnicas estadísticas multivariadas confiables en el análisis simultáneo de diferentes variables independientes sobre un desenlace. Objetivo: Determinar la aplicación de la validez racional y de apariencia en la metodología empleada para el estudio de la causalidad en salud. Métodos: Para evaluar si la metodología se correspondía con los requerimientos de la investigación, se aplicó la validez de apariencia para valorar los resultados obtenidos en su aplicación, específicamente, si las reglas reflejan verazmente, lo que ocurre en la práctica médica, mediante el empleo de la validez racional. Resultados: Los usuarios potenciales de la metodología la consideraron aceptable en los aspectos medidos sobre la regresión logística binaria. El mayor porcentaje de las reglas analizadas está en correspondencia con lo planteado en la literatura, pocas plantean aspectos que no se dan necesariamente en la práctica médica, pero tampoco se contradicen con la literatura. Los resultados de la validez de apariencia no fueron favorables, pues la metodología no había sido empleada antes en el contexto. En cuanto a la validez racional, se verificó un alto porcentaje de correspondencia entre lo planteado por las reglas y la literatura. Es importante tener en cuenta, que el hallazgo de algo conocido reafirma la validez de esa regla. Conclusiones: Las reglas obtenidas de la aplicación de la metodología reflejan, en general, lo que ocurre en la práctica médica.

Introduction: the fundamental objective of medicine is to determine the causes that produce diseases. At the end of the 20th century, multivariate statistical techniques were used as reliable in the simultaneous analysis of different independent variables on an outcome. Objective: to determine the application of appearance and rational validity of a methodology to study causality in health. Methods: to evaluate whether the methodology corresponded to the research requirements, appearance validity was applied to assess the results obtained in its application, specifically, if the rules accurately reflect what happens in medical practice, through the use of rational validity. Results: the potential users of the methodology considered it acceptable in the measured aspects of the binary logistic regression. The highest percentage of the rules analyzed is in correspondence with what is stated in the literature; few raise aspects that do not necessarily occur in medical practice, but they do not contradict the literature either. The results of face validity were not favourable, since the methodology had not been used before in the context. A high percentage of correspondence regarding rational validity was verified between what was stated by the rules and the literature. It is important to note that finding something known reaffirms the validity of that rule. Conclusions: the rules obtained from the application of the methodology reflect, in general, what happens in medical practice.

Plano de análise estatística de um ensaio clínico randomizado em cluster em unidades de terapia intensiva geral adulto no Brasil: TELE-critical care verSus usual Care On ICU PErformance (TELESCOPE) / Statistical analysis of a cluster-randomized clinical trial on adult general intensive care units in Brazil: TELE-critical care verSus usual Care On ICU PErformance (TELESCOPE) trial

RESUMO Objetivo: O ensaio TELE-critical Care verSus usual Care On ICU PErformance (TELESCOPE) visa avaliar se uma intervenção complexa por telemedicina em unidades de terapia intensiva, que se concentra em rondas multidisciplinares diárias realizadas por intensivistas a distância, reduzirá o tempo de permanência na unidade de terapia intensiva em comparação com os cuidados habituais. Métodos: O TELESCOPE é um ensaio nacional, multicêntrico, controlado, aberto, randomizado em cluster. O estudo testa a eficácia de rondas multidisciplinares diárias realizadas por um intensivista por meio de telemedicina em unidades de terapia intensiva brasileiras. O protocolo foi aprovado pelo Comitê de Ética em Pesquisa local do centro coordenador do estudo e pelo Comitê de Ética em Pesquisa local de cada uma das 30 unidades de terapia intensiva, de acordo com a legislação brasileira. O ensaio está registado no ClinicalTrials.gov (NCT03920501). O desfecho primário é o tempo de internação na unidade de terapia intensiva, que será analisado considerando o período basal e a estrutura dos dados em cluster, sendo ajustado por covariáveis predefinidas. Os desfechos exploratórios secundários incluem a classificação de desempenho da unidade de terapia intensiva, a mortalidade hospitalar, a incidência de infecções nosocomiais, o número de dias sem ventilação mecânica aos 28 dias, a taxa de pacientes que recebem alimentação oral ou enteral, a taxa de pacientes sob sedação leve ou em alerta e calmos e a taxa de pacientes sob normoxemia. Conclusão: De acordo com as melhores práticas do ensaio, divulgamos nossa análise estatística antes de bloquear a base de dados e iniciar as análises. Esperamos que essa prática de notificação evite o viés das análises e aprimore a interpretação dos resultados apresentados. Registro no ClinicalTrials.gov:NCT03920501

ABSTRACT Objective: The TELE-critical Care verSus usual Care On ICU PErformance (TELESCOPE) trial aims to assess whether a complex telemedicine intervention in intensive care units, which focuses on daily multidisciplinary rounds performed by remote intensivists, will reduce intensive care unit length of stay compared to usual care. Methods: The TELESCOPE trial is a national, multicenter, controlled, open label, cluster randomized trial. The study tests the effectiveness of daily multidisciplinary rounds conducted by an intensivist through telemedicine in Brazilian intensive care units. The protocol was approved by the local Research Ethics Committee of the coordinating study center and by the local Research Ethics Committee from each of the 30 intensive care units, following Brazilian legislation. The trial is registered with ClinicalTrials. gov (NCT03920501). The primary outcome is intensive care unit length of stay, which will be analyzed accounting for the baseline period and cluster structure of the data and adjusted by prespecified covariates. Secondary exploratory outcomes included intensive care unit performance classification, in-hospital mortality, incidence of nosocomial infections, ventilator-free days at 28 days, rate of patients receiving oral or enteral feeding, rate of patients under light sedation or alert and calm, and rate of patients under normoxemia. Conclusion: According to the trial's best practice, we report our statistical analysis prior to locking the database and beginning analyses. We anticipate that this reporting practice will prevent analysis bias and improve the interpretation of the reported results. ClinicalTrials.gov registration:NCT03920501

Pitfalls and perils of survival analysis under incorrect assumptions: the case of COVID-19 data / Escollos y peligros del análisis de supervivencia: el caso de los datos de COVID-19

Abstract | Non-parametric survival analysis has become a very popular statistical method in current medical research. However, resorting to survival analysis when its fundamental assumptions are not fulfilled can severely bias the results. Currently, hundreds of clinical studies are using survival methods to investigate factors potentially associated with the prognosis of coronavirus disease 2019 (COVID-19) and test new preventive and therapeutic strategies. In the pandemic era, it is more critical than ever to base decision-making on evidence and rely on solid statistical methods, but this is not always the case. Serious methodological errors have been identified in recent seminal studies about COVID-19: One reporting outcomes of patients treated with remdesivir and another one on the epidemiology, clinical course, and outcomes of critically ill patients. High-quality evidence is essential to inform clinicians about optimal COVID-19 therapies and policymakers about the true effect of preventive measures aiming to tackle the pandemic. Though timely evidence is needed, we should encourage the appropriate application of survival analysis methods and careful peer-review to avoid publishing flawed results, which could affect decision-making. In this paper, we recapitulate the basic assumptions underlying non-parametric survival analysis and frequent errors in its application and discuss how to handle data on COVID-19.

Resumen | El análisis de supervivencia es un método estadístico muy popular en la investigación médica actual. Sin embargo, el recurrir al análisis de supervivencia cuando no se cumplen sus supuestos fundamentales puede sesgar gravemente los resultados. Actualmente, cientos de estudios clínicos están utilizando esta metodología para estudiar los factores potencialmente asociados con el pronóstico de la COVID-19 y probar nuevas estrategias preventivas y terapéuticas. En la pandemia actual es más importante que nunca que las decisiones se basen en pruebas y en métodos estadísticos sólidos. Sin embargo, este no es siempre el caso. Se han detectado errores metodológicos graves en estudios seminales recientes sobre COVID-19: uno que informa los resultados de los pacientes tratados con remdesivir y otro sobre la epidemiología, el curso clínico y los resultados de los pacientes críticamente enfermos. La evidencia de calidad es esencial para informar a los médicos sobre las terapias óptimas contra la enfermedad y, a los legisladores, sobre el verdadero efecto de las medidas preventivas destinadas a abordar la pandemia. Aunque se necesitan pruebas oportunas, debemos fomentar la aplicación adecuada de los métodos de análisis de supervivencia y una cuidadosa revisión por pares para evitar la publicación de resultados defectuosos que pueden afectar la adopción de decisiones. En este artículo, recapitulamos los supuestos básicos que subyacen al análisis de supervivencia y los errores frecuentes en su aplicación, y discutimos cómo manejar los datos sobre la COVID-19.

O valor de p é adequadamente interpretado pelos profissionais de terapia intensiva? Uma pesquisa on-line / Is the p-value properly interpreted by critical care professionals? Online survey

RESUMO Objetivo: Determinar a prevalência e os fatores de risco para conhecimento insuficiente sobre valores de p entre médicos e terapeutas respiratórios atuantes em terapia intensiva na Argentina. Métodos: Levantamento transversal on-line com 25 questões relativas às características dos participantes, autopercepção e conhecimento sobre valores de p (teoria e prática). Realizaram-se análises de estatística descritiva e regressão logística multivariada. Resultados: Analisaram-se 376 participantes. Não tinham conhecimento a respeito dos valores de p 237 participantes (63,1%). Segundo análise de regressão logística multivariada, falta de treinamento em metodologia científica (RC ajustadas 2,50; IC95% 1,37 - 4,53; p = 0,003) e a quantidade de leitura (< 6 artigos científicos por ano; RC ajustadas 3,27; IC95% 1,67 - 6,40; p = 0,001) foram identificados como independentemente associados com a falta de conhecimento sobre valores de p por parte dos participantes. Conclusão: A prevalência de conhecimento insuficiente com relação a valores de p entre médicos e terapeutas respiratórios na Argentina foi de 63%. Falta de treinamento em metodologia científica e quantidade de leitura (< 6 artigos científicos por ano) foram identificados como independentemente associados com a falta de conhecimento sobre valores de p por parte dos participantes.

ABSTRACT Objective: To determine the prevalence of and risk factors for insufficient knowledge related to p-values among critical care physicians and respiratory therapists in Argentina. Methods: This cross-sectional online survey contained 25 questions about respondents' characteristics, self-perception and p-value knowledge (theory and practice). Descriptive and multivariable logistic regression analyses were conducted. Results: Three hundred seventy-six respondents were analyzed. Two hundred thirty-seven respondents (63.1%) did not know about p-values. According to the multivariable logistic regression analysis, a lack of training on scientific research methodology (adjusted OR 2.50; 95%CI 1.37 - 4.53; p = 0.003) and the amount of reading (< 6 scientific articles per year; adjusted OR 3.27; 95%CI 1.67 - 6.40; p = 0.001) were found to be independently associated with the respondents' lack of p-value knowledge. Conclusion: The prevalence of insufficient knowledge regarding p-values among critical care physicians and respiratory therapists in Argentina was 63%. A lack of training on scientific research methodology and the amount of reading (< 6 scientific articles per year) were found to be independently associated with the respondents' lack of p-value knowledge.

Impacto sobre el tamaño de las muestras en estudios nacionales si cambiara el nivel de significación estadística de α= 0,05 a α = 0,005

Background: The statistical significance α = 0.05 is the cut-off point used to decide whether a hypothesis is statistically significant. When p-value is less than 0.05, we reject the null hypothesis. Although this criterion has been used for almost a century to generate new knowledge, there is currently an international discussion about the need to decrease the significance to α = 0.005. Aim: To determine the effects that changing the p value would have on the sample size of different types of studies. Material and Methods: A series of formulas for calculating the sample size of cross-sectional and comparative studies were used to create case scenarios. Results: By changing α = 0.05 to α = 0.005, the sample sizes in cross-sectional studies would double and in comparative studies would increase between 60% and 70%, depending on the statistical power chosen. Conclusions: Considering the sample size implications, the change in the level of significance would have important effects on the Chilean science. The cost of a randomized clinical trial could increase by at least 27% to 32%. This increase could be similar for cross-sectional studies. With an investment of less than 0.4% of gross domestic product in science and technology, national scientific research would become more expensive, distributing the few available resources among fewer projects. This effect should be considered in any discussion about national budget for science and technology.

Current status of acute pancreatitis related clinical trial registrations in China / 中华胰腺病杂志

Objective:To analyze the registration status of acute pancreatitis-related clinical studies registered on the Chinese Clinical Trial Registry (ChiCTR) and USA ClinicalTrials.gov database.Methods:The ChiCTR and ClinicalTrials.gov database were searched to collect, sort and analyze the clinical studies related to acute pancreatitis registered from the establishment of the database to December 31, 2020. The clinical trials were manually grouped, and the features of clinical researches were compared based on different registered data (2007-2014 vs 2015-2020) and different financial sources (self-support, enterprise support or public support). Results:A total of 157 registered clinical studies related to acute pancreatitis have been included (ChiCTR n=99; ClinicalTrial.gov n=58). The top three areas with the greatest number of registered clinical studies were Sichuan (28.0%), Shanghai (14.6%) and Jiangsu (12.1%), totally accounting for 54.7%. There were 91 interventional studies, 41 observational studies and 25 other type studies. Masking was performed in 34 studies (21.6%). Randomized parallel controlling was performed in 84 studies (53.5%). 30 trials (19.1%) were at Ⅳ phase, and 7 trials (4.4%) were at Ⅱ or Ⅲ phase. 2007-2014 group tended to use randomized parallel controlled design (68.3% vs 45.4%, P=0.005) and randomization grouping (76.7% vs 47.4%, P=0.001). 2015-2020 group tended to use relatively large sample (72.6% vs 47.4%, P=0.002)and data management committee (53.6% vs 25.0%, P=0.001). The differences between the two groups were statistically significant. Of 92 trials from ChiCTR database, 48 were self-supported, 5 was supported by enterprise, and 38 was supported by the public. The percentage of self-support and public support was 86.9%. Conclusions:The number of acute pancreatitis-related clinical studies registered on ChiCTR was generally on the increase. Most registered studies were funded by public finances or by the researchers' institutions self. There was a lack of phaseⅡ or phase Ⅲ.

Estructura de comunidades en las redes semánticas de la investigación biomédica sobre disparidades en salud y sexismo / Structure of communities in semantic networks of biomedical research on disparities in health and sexism

Resumen: Introducción. Como una iniciativa para mejorar la calidad de la atención sanitaria, en la investigación biomédica se ha incrementado la tendencia centrada en el estudio de las disparidades en salud y sexismo. Objetivo. Caracterizar la evidencia científica sobre la disparidad en salud definida como la brecha existente entre la distribución de la salud y el posible sesgo por sexo en el acceso a los servicios médicos. Materiales y métodos. Se hizo una búsqueda simultánea de la literatura científica en la base de datos Medline PubMed de dos descriptores fundamentales: Healthcare disparities y Sexism. Posteriormente, se construyó una red semántica principal y se determinaron algunas subunidades estructurales (comunidades) para el análisis de los patrones de organización de la información. Se utilizó el programa de código abierto Cytoscape para el analisis y la visualización de las redes y el MapEquation, para la detección de comunidades. Asimismo, se desarrolló código ex profeso disponible en un repositorio de acceso público. Resultados. El corpus de la red principal mostró que los términos sobre las enfermedades del corazón fueron los descriptores de condiciones médicas más concurrentes. A partir de las subunidades estructurales, se determinaron los patrones de información relacionada con las políticas públicas, los servicios de salud, los factores sociales determinantes y los factores de riesgo, pero con cierta tendencia a mantenerse indirectamente conectados con los nodos relacionados con condiciones médicas. Conclusiones. La evidencia científica indica que la disparidad por sexo sí importa para la calidad de la atención de muchas enfermedades, especialmente aquellas relacionadas con el sistema circulatorio. Sin embargo, aún se percibe un distanciamiento entre los factores médicos y los sociales que dan lugar a las posibles disparidades por sexo.

Abstract: Introduction: As an initiative to improve the quality of health care, the trend in biomedical research focused on health disparities and sex has increased. Objective: To carry out a characterization of the scientific evidence on health disparity defined as the gap between the distribution of health and the possible gender bias for access to medical services. Materials and methods: We conducted a simultaneous search of two fundamental descriptors in the scientific literature in the Medline PubMed database: healthcare disparities and sexism. Subsequently, a main semantic network was built and some structural subunits (communities) were identified for the analysis of information organization patterns. We used open-source software: Cytoscape to analyze and visualize the semantic network, and MapEquation for community detection, as well as an ad hoc code available in a public access repository. Results: The core network corpus showed that the terms on heart disease were the most common among the descriptors of medical conditions. Patterns of information related to public policies, health services, social determinants, and risk factors were identified from the structural subunits, but with a certain tendency to remain indirectly connected to the nodes of medical conditions. Conclusions: Scientific evidence indicates that gender disparity does matter for the care quality in many diseases, especially those related to the circulatory system. However, there is still a gap between the medical and social factors that give rise to possible disparities by sex.

Covid-19 en Colombia: los primeros 90 días / COVID-19 in Colombia: The first 90 days

RESUMEN La epidemia de covid-19 se inició en Colombia el 6 de marzo 2020, cuatro meses después de los primeros casos en China, y cuando ya la enfermedad empezaba a ocasionar serios estragos en Europa. En este artículo se describen y se presentan los registros gráficos de algunas características epidemiológicas de la epidemia en nuestro medio, analizando su tasa de crecimiento, su compromiso por grupos etarios, y su letalidad. Finalmente, se describen los riesgos y la incertidumbre de las proyecciones futuras.

SUMMARY Covid-19 epidemic began in Colombia on March 6, 2020, four months after the first cases in China, and when the disease was already starting to have serious consequences in Europe. This article presents graphic records and describes epidemiological characteristics of the epidemic in our country, analyzing its growth rate, its behavior in different age groups, and its fatality rate. Finally, the risks and the uncertainties of future projections are described.

Effect of Hospital Accreditation Process in Outcomes of Patients with Acute Coronary Syndrome

Abstract Background: Hospital accreditation has as goal the standardization of patient care, aiming quality improvement. On 2015, a cardiology reference hospital was evaluated and got level 3 from ONA in care given to Acute Coronary Syndrome (ACS) patients. Objetive: To compare length of stay (LOS) at Coronary Care Unit (CCU) and the total LOS at the hospital of ACS patients before and after ONA 3 accreditation. Other clinical outcomes were also analyzed. Methods: Systematic and prospective registry of admitted ACS patients at CCU, whose population was divided into pre-accreditation (period 1) and post-accreditation (period 2). Descriptive analysis was performed. For statistical analysis the Mann-Whitney test, chi-squared, Fisher's exact test and Multiple Linear Regression were performed. P value was considered statistically significant when < 0,05. Results: 372 patients were admitted with ACS, 186 in period 1, of which 47 (25,3%) with ST segment Elevation Myocardial Infarction (STEMI), and 186 in period 2, of which 70 (37,6%) with STEMI. The mean age was 65,9 years (± 12,2). About the CCU LOS, there was a reduction from 3 (IQR: 2-4) to 2,5 days (IQR: 2-4; p value = 0,088). Regarding the hospital LOS, there was also a reduction from 8 (IQR: 5-12,25) to 6 days (IQR:4-11; p value = 0,004). Analyzing the type of ACS, there was a significant reduction only at the hospital LOS in non-STEMI patients: 8 to 6 days (p value = 0,001). Other hospitalization length of stay and clinical outcomes did not present a significant reduction in the comparison. Conclusion: After the ONA 3 accreditation, there was a reduction of hospital LOS. There were no significant differences in the other outcomes analyzed.

Metodología para mejorar la calidad comunicativa de la información estadística en profesionales de la salud / Methodology to improve the communicative quality of the statistical information in professionals of the health

RESUMEN En la actualidad un requisito de idoneidad para el profesional de la salud se enfoca a la comunicación de la información estadística. Sin embargo, diversas investigaciones realizadas en Cuba y el extranjero confirman que esto constituye aún una limitante para este profesional. Por tal razón, el presente artículo tiene como objetivo ofrecer una metodología para mejorar la calidad comunicativa de la información estadística de los profesionales de la salud. Para ello, se sistematizan diversos referentes teóricos relacionados con la comunicación desde una perspectiva psicológica y de la didáctica de la Estadística. La metodología propuesta se valoró por medio de criterio de especialistas que avaló su adecuada pertinencia, coherencia y posible factibilidad de aplicación práctica.

ABSTRACT At present, a suitability requisite for the professional of the health focuses on the communication of the statistical information. Nevertheless, diverse investigations carried out in Cuba and the foreigner confirm that this constitutes still a limitation for this professional. For such a reason, the present article takes as objective to offer a methodology to improve the communicative quality of the statistical information of the professionals of the health. For it, it is systematized diverse theoretical bases related to the communication from a psychological perspective and of the didactics of the Statistics. The proposed methodology was valued by means of specialists' criteria that endorsed its suitable relevancy, coherence and possible practicality of practical application.

Métodos actuales para asegurar la validez de los estudios de causalidad en Medicina / Current methods to assure the validity of the causality studies in Medicine

RESUMEN Fundamento: Los estudios de causalidad deben aportar resultados certeros, lo cual depende de la adecuación de los mismos, de ahí la necesidad de conocer los métodos que aseguren la validez de estas investigaciones. Objetivo: Sistematizar los métodos actuales para el estudio de causalidad en Medicina que incluye el diseño, los requerimientos que aseguran su validez y los métodos para el cumplimiento de estos requerimientos. Desarrollo: Se realizó una revisión bibliográfica en bases de datos biomédicas, se seleccionó la literatura de mayor actualidad, integralidad y cientificidad con la cual se organizó una síntesis crítica, a la que se le agregó la experiencia de las autoras. Se presentan técnicas para la detección y tratamiento de la confusión y la interacción y para garantizar la comparabilidad entre grupos. Entre las técnicas se destacan la aleatorización mendeliana, el puntaje de susceptibilidad, los G-métodos, los modelos estructurales marginales y anidados, la lógica difusa y el análisis estadístico implicativo. Conclusiones: A pesar del avance en los métodos estadísticos es el investigador el encargado de garantizar la no confusión residual y discernir entre lo estadísticamente significativo y lo clínicamente aceptable.

ABSTRACT Background: Causality studies must provide accurate results, which depends on their adequacy, therefore the need of knowing the methods that ensure the validity of these investigations. Objective: To systematize the current methods for the study of causality in Medicine that includes the design, the requirements that ensure its validity and the methods for complying with these requirements. Development: It was carried out a bibliographic review in biomedical databases and selected the most current, comprehensive, scientific literature, with this, a critical synthesis was organized, with the experience of the authors. Techniques for the detection and treatment of confusion and interaction were presented, also to ensure comparability between groups. Among the techniques, Mendelian randomization, susceptibility score, G-methods, marginal and nested structural models, fuzzy logic and implicative statistical analysis stand out. Conclusions: Despite the progress in statistical methods, the researcher is responsible for guaranteeing residual non-confusion and distinguishing between statistically significant and clinically acceptable.

Endovascular Treatments Performed Collaboratively by the Society of Korean Endovascular Neurosurgeons Members: A Nationwide Multicenter Survey

OBJECTIVE: Since less invasive endovascular treatment was introduced to South Korea in 1994, a considerable proportion of endovascular treatments have been performed by neuroradiology doctors, and endovascular treatments by vascular neurosurgeons have recently increased. However, few specific statistics are known regarding how many endovascular treatments are performed by neurosurgeons. Thus, authors compared endovascular treatments collaboratively performed by vascular neurosurgeons with all cases throughout South Korea from 2013 to 2017 to elucidate the role of neurosurgeons in the field of endovascular treatment in South Korea.METHODS: The Society of Korean Endovascular Neurosurgeons (SKEN) has issued annual reports every year since 2014. These reports cover statistics on endovascular treatments collaboratively or individually performed by SKEN members from 2013 to 2017. The data was requested and collected from vascular neurosurgeons in various hospitals. The study involved 77 hospitals in its first year, and 100 in its last. National statistics on endovascular treatment from all over South Korea were obtained from the Healthcare Bigdata Hub website of the Health Insurance Review & Assessment Service based on the Electronic Data Interchange (EDI) codes (in the case of intra-arterial (IA) thrombolysis, however, statistics were based on a combination of the EDI and I63 codes, a cerebral infarction disease code) from 2013 to 2017. These two data sets were directly compared and the ratios were obtained.RESULTS: Regionally, during the entire study period, endovascular treatments by SKEN members were most common in Gyeonggi-do, followed by Seoul and Busan. Among the endovascular treatments, conventional cerebral angiography was the most common, followed by cerebral aneurysmal coiling, endovascular treatments for ischemic stroke, and finally endovascular treatments for vascular malformation and tumor embolization. The number of endovascular treatments performed by SKEN members increased every year.CONCLUSION: The SKEN members have been responsible for the major role of endovascular treatments in South Korea for the recent 5 years. This was achieved through the perseverance of senior members who started out in the midst of hardship, the establishment of standards for the training/certification of endovascular neurosurgery, and the enthusiasm of current SKEN members who followed. To provide better treatment to patients, we will have to make further progress in SKEN.

Endovascular Treatments Performed Collaboratively by the Society of Korean Endovascular Neurosurgeons Members: A Nationwide Multicenter Survey

OBJECTIVE: Since less invasive endovascular treatment was introduced to South Korea in 1994, a considerable proportion of endovascular treatments have been performed by neuroradiology doctors, and endovascular treatments by vascular neurosurgeons have recently increased. However, few specific statistics are known regarding how many endovascular treatments are performed by neurosurgeons. Thus, authors compared endovascular treatments collaboratively performed by vascular neurosurgeons with all cases throughout South Korea from 2013 to 2017 to elucidate the role of neurosurgeons in the field of endovascular treatment in South Korea. METHODS: The Society of Korean Endovascular Neurosurgeons (SKEN) has issued annual reports every year since 2014. These reports cover statistics on endovascular treatments collaboratively or individually performed by SKEN members from 2013 to 2017. The data was requested and collected from vascular neurosurgeons in various hospitals. The study involved 77 hospitals in its first year, and 100 in its last. National statistics on endovascular treatment from all over South Korea were obtained from the Healthcare Bigdata Hub website of the Health Insurance Review & Assessment Service based on the Electronic Data Interchange (EDI) codes (in the case of intra-arterial (IA) thrombolysis, however, statistics were based on a combination of the EDI and I63 codes, a cerebral infarction disease code) from 2013 to 2017. These two data sets were directly compared and the ratios were obtained. RESULTS: Regionally, during the entire study period, endovascular treatments by SKEN members were most common in Gyeonggi-do, followed by Seoul and Busan. Among the endovascular treatments, conventional cerebral angiography was the most common, followed by cerebral aneurysmal coiling, endovascular treatments for ischemic stroke, and finally endovascular treatments for vascular malformation and tumor embolization. The number of endovascular treatments performed by SKEN members increased every year. CONCLUSION: The SKEN members have been responsible for the major role of endovascular treatments in South Korea for the recent 5 years. This was achieved through the perseverance of senior members who started out in the midst of hardship, the establishment of standards for the training/certification of endovascular neurosurgery, and the enthusiasm of current SKEN members who followed. To provide better treatment to patients, we will have to make further progress in SKEN.

A interpretação estatística como produção de verdades: reflexões éticas / The statistics interpretation as production of truths: ethical insights / La interpretación estadística como producción de verdades: reflexiones éticas

Resumo Este ensaio lança um olhar crítico sobre as consequências, na prática do profissional de saúde, da produção de verdades científicas com base em modelos estatísticos. A estatística nos oferece visão probabilística de eventos naturais observados sistematicamente, e vários são os limites intrínsecos a seus métodos. Mas, no senso comum do meio científico, criou-se o imaginário da estatística como meio para obter verdades a respeito de sistemas complexos, da mesma forma que cientistas postulam princípios para a órbita dos planetas. Nesse contexto, as expectativas de sucesso ou fracasso em intervenções e a avaliação dos riscos e benefícios da aplicação de resultados experimentais podem ser perigosamente comprometidas no dia a dia da prática biomédica.

Abstract This essay aims to raise critical awareness about the bioethical risk of the understanding of statistics, as the production of scientific truths, within the practical life of the health professional. Statistics give us a probabilistic view of the natural events observed systematically, with innumerable limits intrinsic to their methods. But the scientific milieu also has its degree of non scientific perception, which created in the collective imagination of the scientific milieu the idea that statistics obtain truths about the complex systems of nature, truths as solid as the scientist's predictions about the orbits of the planets. Thus, the construction of expectations of success and failure in interventions, as well as the careful evaluation of the risks and benefits of the application of experimental results in human life, can be dangerously compromised in the day to day of the biomedical practices.

Resumen Este ensayo tiene el objetivo de suscitar la conciencia crítica acerca del riesgo bioético de la comprensión de la estadística como producción de verdades científicas en la vida práctica del profesional de salud. La estadística nos ofrece una visión probabilística de los eventos naturales observados sistemáticamente, con innumerables límites intrínsecos a sus métodos. Pero el medio científico también tiene su sentido común. Se creó en el imaginario colectivo del medio científico la idea de que la estadística obtiene verdades respecto de los sistemas complejos de la naturaleza, verdades tan sólidas como las predicciones del científico acerca de las órbitas de los planetas. Así, la construcción de expectativas de éxito y fracaso en intervenciones, así como la evaluación criteriosa de los riesgos y beneficios de la aplicación de resultados experimentales en la vida humana, pueden verse peligrosamente comprometidos en el día a día de las prácticas biomédicas.

Análisis interino en ensayos clínicos: un estudio meta-epidemiológico / Interim analysis in clinical trials: A meta-epidemiological study / Análise interino em ensaios clínicos: um estudo meta-epidemiológico

Objetivo: la responsabilidad ética del investigador obliga al monitoreo de la seguridad de los participantes a través del estudio y, por ende, se requiere de un comité de monitoreo de datos, cuya tarea principal es el análisis interino que se refiere a la supervisión de variables como beneficios dramáticos, efectos adversos, mortalidad y futilidad, que lleven a la terminación temprana del estudio. El objetivo de esta investigación es determinar los métodos estadísticos más utilizados en el análisis interino en los ensayos clínicos aleatorizados y publicados en 2016 en una revista médica general de alto factor de impacto. Metodología: se realizó un estudio meta-epidemiológico descriptivo, constituido por ensayos clínicos aleatorizados publicados en el The New England Journal of Medicine, desde el 7 de enero hasta el 10 de noviembre de 2016. Resultados: se analizaron 104 artículos con una muestra promedio de 5 531 ± 762 pacientes y un tiempo de seguimiento promedio de 31 ± 45 meses. De los estudios evaluados se encontró que 88 (84.61%) realizaron análisis interino y 16 (15.38%) no lo realizaron. Los métodos estadísticos utilizados en los artículos fueron O'Brien-Fleming en 30 (34.09%), Haybittle-Peto en 13 (14.77%); otros métodos en dos (2.27%) y no especificado en 43 (48.86%) de ellos. Conclusiones: la mayoría de los ensayos clínicos aleatorizados realizó análisis interino y lo describen en su protocolo. Aproximadamente la mitad de los estudios no especificó el método estadístico; sin embargo, el método descrito más utilizado fue O'Brien-Fleming y, en segundo lugar, Haybittle-Peto y en ningún estudio se especificó el método de Pocock.

Objective: The ethical responsibility of the researcher requires that the safety of participants be monitored throughout the study. Thus, a data monitoring committee is required, whose main function is the interim analysis, which monitors variables such as dramatic benefits, adverse effects, mortality and futility that lead to the early termination of a study. The objective of this study is to determine the most frequently used statistical methods in interim analysis in randomized clinical trials published during 2016 in a high impact factor medical journal. Methodology: Meta-epidemiological descriptive study, consisting of randomized clinical trials published in The New England Journal of Medicine from January 7 to November 10 of 2016. Results: 104 articles were analyzed, where the mean sample was 5,531 ± 762 patients and and average follow-up time was 31 ± 45 months. Of the studies evaluated, 88 (84.61%) performed interim analysis, while 16 (15.38%) did not. Regarding statistical methods used, O'Brien-Fleming was used in 30 (34.09%) studies, Haybittle-Peto in 13 (14.77%), other methods in two (2.27%), and the method was not specified in 43 (48.86%). Conclusions: most of the randomized clinical trials reviewed had interim analysis and described it in their protocol. Approximately half of the studies did not specify the statistical method; however, the most commonly described method was O'Brien-Fleming, followed by Haybittle-Peto; no study used the Pocock method.

Objetivo: a responsabilidade ética do investigador obriga à monitoração da segurança dos participantes através do estudo e, por consequência, se requere de um comitê de monitoração de dados, cuja a tarefa principal é a análise interino que se refere à supervisão de variáveis como benefícios dramáticos, efeitos adversos, mortalidade e futilidade, que levem à terminação precoce do estudo. O objetivo desta investigação é determinar os métodos estatísticos mais utilizados na análise interino nos ensaios clínicos aleatorizados e publicados em 2016 em uma revista médica geral de alto fator de impacto. Metodologia: se realizou um estudo meta-epidemiológico descritivo, constituído por ensaios clínicos aleatorizados publicados no The New England Journal of Medicine, desde o dia 7 de Janeiro até o dia 10 de novembro de 2016. Resultados: se analisaram 104 artigos com uma amostra média de 5 531 ± 762 pacientes e um tempo de seguimento médio de 31 ± 45 meses. Dos estudos avaliados se encontrou que 88 (84.61%) realizaram análise interino e 16 (15.38%) não o realizaram. Os métodos estatísticos utilizados nos artigos foram O'Brien-Fleming em 30 (34.09%), Haybittle-Peto em 13 (14.77%); outros métodos em dois (2.27%) e não especificado em 43 (48.86%) deles. Conclusões: a maioria dos ensaios clínicos aleatorizados realizou análise interino e o descrevem no seu protocolo. Aproximadamente a metade dos estudos não especificou o método estatístico; mas, o método descrito mais utilizado foi O'Brien-Fleming e, em segundo lugar, Haybittle-Peto e em nenhum estudo se especificou o método de Pocock.

Reference value in normal adult echocardiography: a retrospective study / 中华全科医师杂志

Objective To observe normal range based on normal adult echocardiography with data mining retrospectively.Methods Analyzed the echocardiography data of 15 553 patients who came to Peking university People's Hospital from Nov 2012 to Nov 2014 without obvious abnormalities of cardiac structure and function.The reference range of 15 parameters were calculated and analyzed in correlation with gender,age and other factors for each group.Results The reference ranges of basic measurement parameters in two-dimensional echocardiography:main pulmonary artery diameter(MPA) (2.14 ± 0.22)cm,diameter of ascending aorta (asc Aorta) (2.87 ± 0.35) cm;The reference ranges of basic measurement parameters in M-mode echocardiography:aortic root diameter (Ao root diam) (2.82 ± 0.35) cm,left atrial dimension (LA dimension) (3.14 ± 0.37) cm,interventricular septal end-diastole thickness (Ⅳsd) (0.86 ±0.12)cm,left ventricular internal diameter at end-diastole (LVIDd)(4.67 ± 0.41)cm,left ventricular internal diameter at end-systole (LVIDs) (2.83 ± 0.34) cm,left ventricular posterior wall end-diastolic thickness(LVPWd) (0.85 ± 0.12) cm,end diastolic volume (EDV) (101.21 ± 19.83) ml,end-systole volume (ESV) (31.09 ± 9.07) ml,ejection fraction (EF) (69.55 ± 5.70) ％;The reference ranges of basic measurement parameters in pulsed doppler echocardiography:mitral A wave velocity (MVA) (73.14 ±16.42) cm/s,mitral E wave velocity(MVE) (84.18 ± 16.17) cm/s,E/A (1.21 ± 0.35),aortic peak velocity (Ao V2 max) (124.95 ± 19.87) cm/s.The measured parameters of males were higher than those of females and value of measured was increased with age for example measured parameters in LVIDd (r =0.225,P =0.00),IVSd(r =0.216,P =0.00),LA dimension (r =0.231,P =0.00) and E/A(r =0.212,P =0.00),with age were positive correlated.The range of 15 parameters in this study and the ASE 2015 guide are similar but have slightly different,such as this research shows that men's left ventricular end-diastolic diameter (4.77 ±0.41) cm,the ASE recommend (5.02 ±0.41) cm which is smaller than the result of this study.And this study for women (4.60 ± 0.40) cm is higher than the ASE recommended (4.50 + 0.36)cm.Conclusions Based on preliminary analysis of large data from normal adult echocardiography,the rang of measured values could be used as a normal reference value of echocardiographyfor routine practice in China.