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.

Meta-análisis de la escala de capital intelectual: implicaciones para hacer frente a la pandemia del COVID-19

Introducción: la medición del capital intelectual como activo intangible se ha establecido a partir de una escala de seis dimensiones relacionada con formación, academia, laboral, profesional, sindical y organizativa. La pandemia ha generado estudios que muestran diferencias significativas entre estas dimensiones, abriendo la discusión sobre la validez metaanalítica. Objetivo: realizar una revisión documental, sistemática y metaanalítica, con una muestra de artículos publicados entre 2014 y 2021 en revistas indexadas en repositorios internacionales. Materiales y métodos: se realizó un estudio documental, sistemático y metaanalítico sobre una muestra de artículos publicados en repositorios internacionales en los últimos dos años. Se utilizó la Escala de Capital Intelectual, considerando sus dimensiones reportadas en la literatura. Resultados: se estableció la estructura y los umbrales de los efectos aleatorios, calculados mediante la ecuación para establecer el parámetro delta, considerando sus intervalos de confianza para la corrección de errores de muestreo y estimación, así como las diferencias entre grupos. Conclusión: se recomienda extender la revisión de la literatura hasta agosto de 2021, para poder contrastar ambas revisiones, y establecer así la validez metaanalítica de la escala, y discutir sus implicaciones en la era COVID-19.

Introduction: the measurement of intellectual capital as an intangible asset has been established from a scale of six dimensions related to training, academia; labor, professional, union, and organizational. The pandemic has generated studies that show significant differences between these dimensions, opening the discussion on meta-analytic validity. Objective: to carry out a documentary, systematic and meta-analytical review with a sample of articles published from 2014 to 2021 in journals indexed in international repositories. Materials and methods: a documentary, systematic and meta-analytical study was carried out on a sample of articles published in international repositories in the last two years. The Intellectual Capital Scale was used, considering its dimensions reported in the literature. Results: the structure and thresholds of the random effects were established, calculated by means of the equation to establish the delta parameter, considering their confidence intervals for correction of sampling and estimation errors, as well as differences between groups. Conclusion: it is recommended to extend the review of the literature until August 2021 in order to be able to contrast both reviews to establish the meta-analytic validity of the scale and discuss its implications in the COVID-19 era.

Factors Predicting Early Major Adverse Events in the Intensive Care Unit After Successful Cardiac Surgery for Congenital Heart Disease in Full-Term Neonates

ABSTRACT Objective: In this study, we aimed to evaluate the factors affecting major adverse event (MAE) development after full-term neonatal cardiac surgery. Methods: This study was conducted retrospectively on newborns who underwent congenital heart surgery between June 1, 2020, and June 1, 2022. MAE was defined as the presence of at least one of the following: cardiac arrest, unplanned reoperation, emergency chest opening, admission to the advanced life support system, and death. The role of blood lactate level, vasoactive inotropic score (VIS), and cerebral near-infrared spectroscopy (NIRS) changes in predicting MAE was investigated. Results: A total of 240 patients (50% male) were operated during the study period. The median age of patients was seven days (interquartile range 3-10 days). MAE was detected in 19.5% of the cases. Peak blood lactate levels >7 mmol/liter (area under the curve [AUC] 0.72, 95% confidence interval [CI] [0.62-0.82], P<0.001, sensitivity 76%, specificity 82%, positive predictive value [PPV] 88%) was an independent risk factor for MAE (odds ratio [OR] 2.7 [95% CI 1.3-6]). More than 30% change in NIRS value during the operative period (AUC 0.84, 95% CI [0.80-0.88], P<0.001, sensitivity 65%, specificity 85%, PPV 90%) was a strong predictor of MAE. VIS > 10 was an independent risk factor (AUC 0.75, 95% CI [0.70-0.84], P<0.001, sensitivity 86%, specificity 80%, PPV 84%) and strongly predicted MAE (OR 1.4 [95% CI 0.9-5]). Conclusion: Cerebral NIRS changes > 30%, high blood lactate levels, and VIS score within the 48 hours may help to predict the development of MAE in the postoperative period.

Validation of Blood Transfusion Risk Scores (TRACK and TRUST) in a Cardiac Surgery Service in Brazil

ABSTRACT Introduction: Transfusion of red blood cells is recurrent in cardiac surgery despite the well-established deleterious effects. Identifying patients with higher chances of requiring blood transfusion is essential to apply strategic preventive measures to reduce such chances, considering the restricted availability of this product. The most used risk scores to predict blood transfusion are the Transfusion Risk and Clinical Knowledge (TRACK) and Transfusion Risk Understanding Scoring Tool (TRUST). However, these scores were not validated for the Brazilian population. The objective of this study was to assess the accuracy of TRACK and TRUST scores in estimating the need for postoperative transfusion of red blood cell concentrates (TRBCC) after cardiac surgery. Methods: A clinical retrospective study was conducted using the database of a Brazilian reference service composed of patients operated between November 2019 and September 2021. Scores were compared using Mann-Whitney U test. Hosmer-Lemeshow goodness of fit test assessed calibration of the scores. Accuracy was assessed using the area under the receiver operating characteristic curve (AUC). All analyses considered a level of significance of 5%. The study was approved by the research ethics committee (CAAE 55577421.4.0000.5201). Results: This study assessed 498 patients. Only the TRACK score presented good calibration (P=0.238; TRUST P=0.034). AUC of TRACK was 0.678 (95% confidence interval 0.63 to 0.73; P<0.001), showing a significant accuracy. Conclusion: Between the scores analyzed, only the TRACK score showed a good calibration, but low accuracy, to predict postoperative TRBCC after cardiac surgery.

Total arterial coronary bypass graft surgery is associated with better long-term survival in patients with multivessel coronary artery disease: a systematic review with meta-analysis

Abstract Introduction: The benefit of total arterial revascularization (TAR) in coronary artery bypass grafting (CABG) remains a controversial issue. This study sought to evaluate whether there is any difference on the long-term results of TAR and non-TAR CABG patients. Methods: The Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), Cochrane Central Register of Controlled Trials (CENTRAL/CCTR), Clinical Trials.gov, Scientific Electronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), and Google Scholar databases were searched for studies published by October 2020. Randomized clinical trials and observational studies with propensity score matching comparing TAR versus non-TAR CABG were included. Random-effects meta-analysis was performed. The current barriers to implementation of TAR in clinical practice and measures that can be used to optimize outcomes were reviewed. Results: Fourteen publications (from 2012 to 2020) involving a total of 22,746 patients (TAR: 8,941 patients; non-TAR: 13,805 patients) were included. The pooled hazard ratio (HR) for long-term mortality (over 10 years) was lower in the TAR group than in the non-TAR group (random effect model: HR 0.676, 95% confidence interval 0.586-0.779, P<0.001). There was evidence of low heterogeneity of treatment effect among the studies for mortality, and none of the studies had a particular impact on the summary result. The result was not influenced by age, sex, or comorbidities. We identified low risk of publication bias related to this outcome. Conclusion: This review found that TAR presents the best long-term results in patients who undergo CABG. Given that many patients are likely to benefit from TAR, its use should be encouraged.

Frailty significantly associated with a risk for mid-term outcomes in elderly chronic coronary syndrome patients: a prospective study

Abstract Introduction: Frailty is a condition of elderly characterized by increased vulnerability to stressful events. Frail patients are more likely to have adverse events. The purposes of this study were to define frailty in patients aged ≥ 70 years with chronic coronary syndrome (CCS) and to evaluate mortality and prognostic significance of frailty in these patients. Methods: We included 99 patients, ≥ 70 years old (mean age 74±5.3 years), with diagnosis of CCS. They were followed-up for up to 12 months. The frailty score was evaluated according to the Canadian Study of Health and Aging (CSHA). All patients were divided as frail or non-frail. The groups were compared for their characteristics and clinical outcomes. Results: Fifty patients were classified as frail, and 49 patients as non-frail. The 12-month Major Adverse Cardiac Events (MACE) rate was 69.4% in frail patients and 20% in non-frail patients. Frailty increases the risk for MACE as much as 3.48 times. Two patients died in the non-frail group and 11 patients died in the frail group. Frailty increases the risk for death as much as 6.05 times. When we compared the aforementioned risk factors by multivariate analysis, higher CSHA frailty score was associated with increased MACE and death (relative risk [RR] = 22.94, 95% confidence interval [CI] 3.33-158.19, P=0.001, for MACE; RR = 7.41, 95% CI 1.44-38.03, P=0.016, for death). Conclusion: Being a frail elderly CCS patient is associated with worse outcomes. Therefore, frailty score should be evaluated for elderly CCS patients as a prognostic marker.

Mid-term outcome after tricuspid valve replacement

Abstract Objective: To evaluate the mid-term survival rate after tricuspid valve replacement (TVR). Methods: We retrospectively studied 110 consecutive patients who underwent TVR from January 2007 to November 2017. A survival analysis was performed with the Kaplan-Meier method and the log-rank test. Results: The median survival was 65.81 months. Mean age was 50 (range 39 to 59) years. Forty-eight patients (43.6%) were male, and 62 patients (56.4%) were female. Most of the patients (78.5%) were categorized into the New York Heart Association (NYHA) functional classes III/IV. Seventy-two patients (65.5%) had isolated TVR. Six-three patients (57.3%) had previously undergone heart surgery. The Kaplan-Meier survival rates at one year, three years, and five years were 59.0%±5%, 52.0%±6%, and 48.0%±6%, respectively. A Cox regression analysis demonstrated that the risk factors for mid-term mortality were advanced NYHA class (hazard ratio [HR] 2.430, 95% confidence interval [CI] 1.099-5.375, P=0.028), need for continuous renal replacement therapy (CRRT) treatment (HR 3.121, 95% CI 1.610-6.050, P=0.001), and need for intra-aortic balloon pump (IABP) treatment (HR 3.356, 95% CI 1.072-10.504, P=0.038). Conclusion: In TVR, impaired cardiac function before the operation and a need for CRRT or IABP treatment after the operation is independently associated with increased mid-term mortality.

Cardiac shock wave therapy for coronary heart disease: an updated meta-analysis

Abstract Introduction: The aim of this article is to study the efficacy and safety of cardiac shock wave therapy (CSWT) in the treatment of coronary heart disease (CAD). Methods: A comprehensive search of electronic databases and a manual search of conference papers and abstracts were performed until September 30, 2018. The studies using RevMan 5.3 and STATA 14.0 softwares were reviewed, and meta-analyses were performed on 13 indicators, such as a six-min walking distance test (6MWT), New York Heart Association (NYHA) functional class, Seattle Angina Questionnaire (SAQ) score, angina class (Canadian Cardiology Society [CCS]), etc. Results: A total of 26 articles were included. The total patient population was 855, of which 781 patients were treated with CSWT. Meta-analyses indicated that 6MWT (mean difference [MD] 75.64, 95% confidence interval [CI] 49.03, 102.25, P<0.00001) and NYHA (MD -0.70, 95% CI -0.92) in the CSWT group were comparable to those in the conventional revascularization group (MD -0.70, 95% CI -0.92, -0.49, P<0.00001). SAQ (MD 10.75, 95% CI 6.66, 14.83, P<0.00001), CCS (MD -0.99, 95% CI -1.13, -0.84, P<0.00001), nitrate dosage (MD -1.84, 95% CI -2.77, -1.12, P<0.00001), LVEF (MD 3.77, 95% CI 2.17, 5.37, P<0.00001), and SSS (MD -4.29, 95% CI -5.61, -2.96, P<0.00001), SRS (MD -2.90, 95% CI -4.85, -0.95, P=0.004), and the exercise test (standard mean difference 0.57, 95% CI 0.12, 1.02, P=0.01) all showed significant differences. Conclusion: CSWT may offer beneficial effects to patients with CAD, but more large-scale clinical studies are needed to further verify its therapeutic effect.

Prognostic value of coronary dominance in patients undergoing elective coronary artery bypass surgery

Abstract Objective: To evaluate the clinical impact of coronary dominance type in terms of early and long-term outcomes in patients undergoing elective coronary artery bypass grafting (CABG). Methods: A total of 844 consecutive patients who underwent elective CABG were divided into two groups based on preoperative angiographic views as left dominant (LD) and right dominant or co-dominant (RD+CD). The measured outcomes were postoperative complications, 30-day mortality, long-term mortality, and major adverse cardiac and cerebrovascular events (MACCE). Results: RD+CD was present in 87.9% (n=742) and LD in 12.1% (n=102) of patients. Postoperative complications, 30-day mortality, and 30-day readmissions were similar in both groups. The median duration of follow-up was 3.4 years. LD was not an independent predictor of mortality (adjusted hazard ratio [HR] 1.53, 95% confidence interval [CI] 0.89-2.45, P=0.12), but it was an independent predictor of MACCE in the long term (adjusted HR 2.18, 95% CI 1.39-3.42, P=0.001). Conclusion: In patients undergoing elective surgical revascularization, left coronary dominance is associated with increased MACCE risk in the long term. Therefore, the assessment of coronary dominance type should be an integral part of outpatient management after CABG.

Is the newly defined r2cha2ds2-vasc score a predictor for late mortality in patients undergoing transcatheter aortic valve replacement?

Abstract Objective: To assess the performance of the modified R2CHA2DS2-VASc score for predicting mid-to-long-term mortality (> 30 days) in patients undergoing transcatheter aortic valve replacement (TAVR). Methods: Data of 78 patients who underwent TAVR were retrospectively reviewed. R2CHA2DS2-VASc score was compared with the European System for Cardiac Operative Risk Evaluation II (EuroSCORE II or ES II) and the transcatheter valve therapytranscatheter aortic valve replacement (TVT-TAVR) risk score. Results: The mean follow-up period was 17.4±9.9 months (maximum 37 months). Early mortality (first 30 days) was observed in 10 (12.8%) patients, whereas mid-to-long-term mortality (> 30 days) was observed in 26 (33.3%) patients. Non-survivors had higher values of R2CHA2DS2-VASc, ES II, and TAVR scores than survivors (P<0.001, P<0.001, and P=0.001, respectively). Analysis of Pearson's correlation revealed that R2CHA2DS2-VASc score was moderately correlated with ES II and TAVR scores (r=0.51, P<0.001; r=0.44, P=0.001, respectively). Pairwise comparisons of R2CHA2DS2-VASc (area under the curve [AUC]: 0.870, 95% confidence interval [CI]: 0.776-0.964; P<0.001), ES II (AUC: 0.801, 95% CI: 0.703-0.899; P<0.001), and TAVR scores (AUC: 0.730, 95% CI: 0.610-852; P=0.002) showed similar accuracy for predicting mortality. R2CHA2DS2-VASc score is an independent predictor of mortality in multivariable Cox regression analysis. A cutoff value of six for R2CHA2DS2-VASc score showed a sensitivity of 74% and a specificity of 89% for predicting mid-to-long-term mortality. Conclusion: R2CHA2DS2-VASc score, easily calculated from clinical parameters, is associated with prediction of mid-to-longterm mortality in patients undergoing TAVR.

German aortic valve score in risk assessment for surgical aortic valve replacement in a brazilian center

Abstract Objective: To test the German Aortic Valve (GAV) score at our university hospital in patients undergoing isolated aortic valve replacement (AVR). Methods: A total of 224 patients who underwent isolated conventional AVR between January 2015 and December 2018 were included. Patients with concomitant procedures and transcatheter aortic valve implantation were excluded. Patients' data were collected and analyzed retrospectively. Patients' risk scores were calculated according to criteria described by GAV score. Sensitivity, specificity, and accuracy (area under the ROC curve [AUC]) were also calculated. The calibration of the model was tested by the Hosmer-Lemeshow method. Results: The mortality rate was 8.04% (18 patients). The patients' mean age was 58.2±19.3 years and 25% of them were female (56 patients). Mean GAV score was 1.73±5.86 (min: 0.0; max: 3.53). The GAV score showed excellent discriminative capacity (AUC 0.925, 95% confidence interval 0.882-0.956; P<0.001). The cutoff "1.8" turned out to be the best discriminatory point with the best combination of sensitivity (88.9%) and specificity (75.7%) to predict operative death. Hosmer-Lemeshow method revealed a P-value of 0.687, confirming a good calibration of the model. Conclusion: The GAV score applies to our population with high predictive accuracy.

Artículo de Revisión / The uncertainties of statistical "significance"

Statistical inference was introduced by Fisher and Neyman-Pearson more than 90 years ago to define the probability that the difference in results between several groups is due to randomness or is a real, "significant" difference. The usual procedure is to test the probability (P) against the null hypothesis that there is no real difference except because of the inevitable sampling variability. If this probability is high we accept the null hypothesis and infer that there is no real difference, but if P is low (P < 0.05) we reject the null hypothesis and infer that there is, a "significant" difference. However, a large amount of discoveries using this method are not reproducible. Statisticians have defined the deficiencies of the method and warned the researchers that P is a very unreliable measure. Two uncertainties of the "significance" concept are described in this review: a) The inefficacy of a P value to discard the null hypothesis; b) The low probability to reproduce a P value after an exact replication of the experiment. Due to the discredit of "significance" the American Statistical Association recently stated that P values do not provide a good measure of evidence for a hypothesis. Statisticians recommend to never use the word "significant" because it is misleading. Instead, the exact P value should be stated along with the effect size and confidence intervals. Nothing greater than P = 0.001 should be considered as a demonstration that something was discovered. Currently, several alternatives are being studied to replace the classical concepts.

Confidence Intervals for Cumulative Incidence Function with Competing Risks Data / 中国卫生统计

Objective The cumulative incidence function (CIF) is an important descriptive indicator for competing risk data in medical follow-up study.However,the upper and lower limits of the classic confidence interval (CI) of CIF may be exclusive the boundaries.In this paper,the CI estimators based on five different transformations and their performances are studied.Methods The CIs of CIF are constructed based on the linear (classical),log,log (-log),arcsine and logit transformation,respectively.Through the simulation study,the average deviations of the false coverage probabilities for all CIs are comprehensively investigated by the ANOVA technology.Results The simulation results show that the CIs based on linear and arcsine transformation have a large positive deviation.Log transformation is prone to fluctuations and has a minimum negative deviation,only log (-log) transformation is closest to the expected constant 0,and most robust and reliable.Conclusion Combined with the simulation results and example,CIs base on linear and log transformation are easy to have wide range and unstable performance,and can not overcome the bounds being negative or above 1;the arcsine and logit is slightly fluctuated,but their performances are relatively balanced;only performance of log(-log) is the most robust and reliable.

Validation of models with proportional bias / Validación de modelos con sesgo proporcional

ABSTRACT Objective. This paper presents extensions to Freese's statistical method for model-validation when proportional bias (PB) is present in the predictions. The method is illustrated with data from a model that simulates grassland growth. Materials and methods. The extensions to validate models with PB were: the maximum anticipated error for the original proposal, hypothesis testing, and the maximum anticipated error for the alternative proposal, and the confidence interval for a quantile of error distribution. Results. The tested model had PB, which once removed, and with a confidence level of 95%, the magnitude of error does not surpass 1225.564 kg ha-1. Therefore, the validated model can be used to predict grassland growth. However, it would require a fit of its structure based on the presence of PB. Conclusions. The extensions presented to validate models with PB are applied without modification in the model structure. Once PB is corrected, the confidence interval for the quantile 1-α of the error distribution enables a higher bound for the magnitude of the prediction error and it can be used to evaluate the evolution of the model for a system prediction.

RESUMEN Objetivo. En este trabajo se presentan extensiones al método estadístico de Freese para validar modelos con sesgo proporcional (SP) en sus predicciones y se ilustra el método con datos provenientes de un modelo de simulación de crecimiento de praderas. Materiales y métodos. Las extensiones para validar un modelo con SP fueron: el error máximo anticipado para el planteamiento original, la prueba de hipótesis y error máximo anticipado para el planteamiento alternativo, y el intervalo de confianza para un cuantil de la distribución de los errores. Resultados. El modelo evaluado presentó SP, una vez removido y con un nivel de confianza del 95% la magnitud del error no sobrepasa 1225.564 kg ha-1. Por lo que el modelo validado podría usarse para predecir el crecimiento de praderas, sin embargo, requerirá un ajuste en su estructura con base a la presencia de SP. Conclusiones. Las extensiones presentadas para validar modelos en presencia de SP se aplican sin que el modelo sea modificado en su estructura. El intervalo de confianza para el cuantil 1-α de la distribución de los errores una vez que se corrige el SP, permite determinar una cota superior para la magnitud del error de predicción y usarla para evaluar la evolución del modelo en predicción del sistema.

Study on manufacturing process performance index of extraction and concentration process of lonicerae japonicae flos of reduning injection / 中草药

Objective To evaluate the probability and quality consistence of Lonicera japonica Flos extraction and concentration intermediate by introducing and applying process performance index (PPI) PPK. Methods With the historical quality analysis date of intermediate of Lonicerae Japonicae Flos extraction and concentration process of Reduning Injection., the confidence intervals of PPK were estimated based on the Bootstrap sampling methods. Results The PPK of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, caffeoylquinic acid, solid holdup was 1.115 6, 1.111 2, 1.117 9, 1.110 9, and 1.560 0 respectively. The PPK of solid holdup is the highest, the PPK of several phenolic acids is lower, but all the PPK can meet the production requirements, showed that the probability and quality consistence of this process is good. The lower limit of 95% confidence intervals of quality indexes was 1.068 3, 1.049 6, 1.066 7, 1.052 1, and 1.495 0 respectively, all greater than 1.000 0, indicating the results were credible. Conclusion The method can be used to evaluate the probability and quality consistence of Lonicerae Japonicae Flos extraction and concentration process, and it provides fundamental evidence on establishing quality standards for releasing or process parameters for releasing.

Statistical Data Editing in Scientific Articles

Scientific journals are important scholarly forums for sharing research findings. Editors have important roles in safeguarding standards of scientific publication and should be familiar with correct presentation of results, among other core competencies. Editors do not have access to the raw data and should thus rely on clues in the submitted manuscripts. To identify probable errors, they should look for inconsistencies in presented results. Common statistical problems that can be picked up by a knowledgeable manuscript editor are discussed in this article. Manuscripts should contain a detailed section on statistical analyses of the data. Numbers should be reported with appropriate precisions. Standard error of the mean (SEM) should not be reported as an index of data dispersion. Mean (standard deviation [SD]) and median (interquartile range [IQR]) should be used for description of normally and non-normally distributed data, respectively. If possible, it is better to report 95% confidence interval (CI) for statistics, at least for main outcome variables. And, P values should be presented, and interpreted with caution, if there is a hypothesis. To advance knowledge and skills of their members, associations of journal editors are better to develop training courses on basic statistics and research methodology for non-experts. This would in turn improve research reporting and safeguard the body of scientific evidence.

Uso de pruebas estadísticas inferenciales en la Revista Cubana de Medicina Militar / Use of Inferential Statistical Tests in the Cuban Journal of Military Medicine

Introducción: desde hace años, existe un debate sobre el uso de las pruebas estadísticas inferenciales en los reportes de resultados de investigación, se destaca la crítica al empleo de las pruebas de significación estadística y sus limitaciones. Objetivos: determinar la frecuencia de empleo de las pruebas de significación estadística (PSE) e intervalos de confianza (IC) por tipos de estudio publicado, cómo se reflejan los resultados de estas, la influencia del tamaño de la muestra, así comosu vinculación con las conclusiones. Resultados: en el periodo 2010 - 2015 de 150 artículos originales, 98 por ciento fueron descriptivos o explicativos y de ellos, el 95 por ciento emplea las PSE, solas o con IC. Predomina el uso de las PSE solas (69 por ciento de los trabajos). En el 25 por ciento se explica la selección del nivel de significación utilizado y el 53 por ciento de los estudios reflejan las cifras exactas de las pruebas realizadas. Solo el 15 por ciento menciona la influencia del tamaño de la muestra en relación con los resultados de las pruebas estadísticas. En las conclusiones, el 86 por ciento de los artículos se refieren adecuadamente a los objetivos del estudio. Conclusiones: predomina el uso de las PSE e IC, fundamentalmente de las PSE, más de la mitad de los trabajos mencionan los resultados precisos de las pruebas, la mayoría no argumenta la relación de estos resultados con el tamaño de la muestra y los autores elaboran las conclusiones de acuerdo con los objetivos planteados en el estudio(AU)

Introduction: For years there has been a debate about the use of inferential statistical tests in the reports of research results, highlighting the criticism to the use of tests of statistical significance and its limitations. Objectives: To determine the frequency of use of statistical significance tests (SST) and confidence intervals (CI) by published study types, how the results are reported, and the influence of sample size, as well as their relationship with the conclusions. Results: In the period 2010-2015 of 150 original articles, 98 percent were descriptive or explanatory and of them, 95 percent used SST alone or with CI. The use of SST alone (69 percent of the articles) predominates. In 25 percent the significance level selection is explained and 53 percent of the studies reflect the exact figures of the tests performed. Only 15 percent mentions the influence of sample size on the results of statistical tests. In the conclusions, 86 percent of the articles refer adequately to the objectives of the study. Conclusions: SST and CI use predominate, mainly SST, more than half of the studies mention the precise results of the tests, most do not argue the relation of these results to the sample size and the authors elaborate the conclusions in accordance with the objectives set out in the study(AU)

Las pruebas de significación estadística: seis décadas de fuegos artificiales / Tests of statistical significance: six decades of fireworks / As provas de significação estatística: seis décadas de fogos artificiais

RESUMEN Tras varios decenios de críticas a las técnicas inferenciales basadas en las pruebas de significación estadística orientadas al rechazo de la llamada "hipótesis nula" y, a pesar del notable consenso alcanzado entre los estadísticos profesionales, este recurso se mantiene vigente tanto en las publicaciones biomédicas, entre ellas las de Salud Pública, como en cursos introductorios de estadística. Entre las muchas deficiencias señaladas por los más prominentes especialistas se destacan tres por ser las más obvias y fáciles de comprender: que no contribuyen a cumplimentar la encomienda de la ciencia, que se conocen de antemano las respuestas a las preguntas que se encaran por su conducto y que los resultados que producen dependen de un elemento ajeno a la realidad estudiada: el tamaño muestral. El artículo discute en detalle tales limitaciones, ilustra su perniciosa presencia en la investigación actual y valora las razones para la subsistencia de la sinrazón en esta materia.

ABSTRACT After decades of criticism against inferential techniques based on statistical significance tests, which mainly reject the so-called "null hypothesis", and in spite of the remarkable consensus among professional statisticians, this resource remains prevalent in both biomedical publications (including public health journals) and introductory statistics courses. Among the many problems identified by the most prominent specialists, three of them are the most obvious and easy to understand: that these tests do not contribute to the actual enterprise of science, that the answers to the questions that are addressed are known in advance and that their results depend critically on an element that is external to the domain that is being studied: sample size. This paper discusses in detail these limitations, illustrates their pernicious presence in current research and evaluates the reasons for the survival of the senselessness in this matter.

RESUMO Trás vários decênios de críticas as técnicas inferenciais baseadas nas provas de significação estatística orientadas ao rejeito da chamada "hipótese nula" e, embora do notável consenso alcançado entre os estatísticos profissionais, este recurso se mantem vigente tanto nas publicações biomédicas, entre elas as de Saúde Pública, como nos cursos introdutórios de estatística. Entre as muitas deficiências assinaladas pelos mais proeminentes especialistas se destacam três por ser as mais obvias e fácies de compreender: que não contribuem a complementar a encomenda da ciência, que se conhecem de antemão as respostas ás perguntas que se encaram pelo seu conduto y que os resultados que produzem depende dum elemento alheio á realidade estudada: o tamanho amostral. O artigo discute em detalhe tais limitações, ilustra a sua perniciosa presença na investigação atual e valora as razões para a subsistência da sem-razão em esta matéria.

Intervalos biológicos de referencia del perfil lipídico / Biological reference intervals of lipid profile

Introducción: La clasificación de la concentración de cualquier analito como patológico o no implica que el valor de la medición sea comparado con valores de individuos similares, para lo cual es necesario obtener intervalos biológicos de referencia (IBR). Los IBR del perfil lipídico adoptados por los laboratorios clínicos son principalmente los propuestos por las casas comerciales y los obtenidos por los paneles de expertos. Sumado a las limitadas publicaciones sobre los IBR del perfil lipídico para nuestra población, es oportuno precisar que variables como el sexo y la edad pueden estar relacionadas con modificaciones en el metabolismo lipídico. Objetivo: Estimar los intervalos biológicos de referencia del perfil lipídico en una población atendida en un laboratorio de Medellín. Métodos: Estudio descriptivo transversal en 81 individuos sanos; los IBR se estimaron a partir del estadístico X±[Zα/2*(DE/√n)], confianza de 95% y precisión de 5%. En el análisis bivariado se utilizó Anova y la prueba t Student. Todo fue realizado en SPSS 21.0®. En los IBR de hombres y mujeres sólo se hallaron diferencias en el colesterol total y los índices colesterol total/cholesterol HDL y triglicéridos/cholesterol HDL. Analizando los grupos etarios, se hallaron diferencias en los triglicéridos y el cholesterol VLDL siendo menor en los adultos jóvenes en comparación con los adultos medios y mayores; para el índice triglicéridos/cholesterol HDL se halló diferencia entre los adultos jóvenes y mayores. Conclusión: Este estudio permitió determinar los IBR del perfil lipídico, los cuales son importantes para el diseño de estrategias de prevención primaria para dislipidemias en la población estudiada. (Acta Med Colomb 2016; 41: 29-35).

Introduction: The classification of the concentration of any analyte as pathological or not, implies that the measurement be compared to values of similar individuals, for which is necessary to obtain Biological Reference Intervals (BRI). The BRI of lipid profile adopted by clinical laboratories are mainly the offered by commercial houses and those obtained by expert panels. In addition to the limited literature on BRI of lipid profile for our population, it is appropriate to specify that variables such as sex and age may be related to changes in lipid metabolism. Objective: to estimate the biological reference intervals of lipid profile in a population treated at a laboratory in Medellin. Methods: Descriptive cross-sectional study in 81 healthy individuals; BRI were estimated statistical X ± [Zα / 2 * (DE / √ n)], 95% confidence and accuracy of 5%. Anova and t Student test was used in the bivariate analysis. Everything was done in SPSS 21.0®. In the BRI of men and women differences were only found in total cholesterol levels and total / HDL cholesterol and triglycerides / HDL cholesterol. Analyzing age groups, differences in triglycerides and VLDL-C were found, being these lower in young adults compared with the middle-aged adults and the elderly; for index triglycerides / VLDL cholesterol difference between young and older adults was found. Conclusion: this study allowed determining the BRI of lipid profile, which are important for designing strategies for primary prevention of dyslipidemia in the studied population. (Acta MedColomb 2016; 41: 29-35).

Significant results: statistical or clinical? / 대한마취과학회지

The null hypothesis significance test method is popular in biological and medical research. Many researchers have used this method for their research without exact knowledge, though it has both merits and shortcomings. Readers will know its shortcomings, as well as several complementary or alternative methods, as such the estimated effect size and the confidence interval.