Análisis bayesiano del maltrato infantil en adolescentes peruanos

Introducción: El maltrato infantil es un problema psicológico frecuente en niños y adolescentes de todo el mundo. La exposición a diversos tipos de maltrato puede conducir a otros problemas psicológicos y físicos, siendo necesario identificar qué tipo de maltrato repercute con mayor probabilidad en hombres y mujeres. Objetivo: Analizar las diferencias del maltrato infantil según sexo en adolescentes peruanos. Método: Estudio transversal, enfoque cuantitativo y comparativo realizado en los meses de julio y agosto de 2022. Se analizó una muestra por conveniencia de 1 376 adolescentes, los cuales respondieron un autoinforme sobre maltrato infantil. Para comparar ambos grupos, se utilizó la prueba U de Mann-Whitney de muestras independientes bayesianas. Resultados: Entre los diversos tipos de maltrato infantil, solo se encontró evidencia a favor de la hipótesis alternativa en el maltrato emocional (BF10=190,38; δ=0,31; IC 95 %: 0,20-0,48), con una evidencia muy fuerte. Esta diferencia fue superior en mujeres (M=8,28) en comparación con los hombres (M=7,09). En la negligencia emocional y física, se reportó evidencia fuerte para la hipótesis nula. El análisis robusto del factor Bayes confirmó los mismos resultados. Conclusiones: El maltrato emocional se presenta mayormente en mujeres adolescentes, siendo el género que requiere mayor apoyo psicológico en este tipo de maltrato infantil. En los otros tipos de maltrato, no se encontró diferencias respecto al sexo. En consecuencia, los profesionales de la salud deben considerar el rol del género en el maltrato emocional, pero no descuidar los otros tipos de maltrato infantil, enfatizando en las particularidades específicas de cada caso.

Introduction: Child maltreatment is a common psychological problem of children and adolescents around the world. Presence of various form of abuse can lead to other psychological and physical problems, so, it is necessary to identify which form of abuse is more likely to affect men and women. Objective: To analyze the differences observed in child maltreatment according to sex in Peruvian adolescents. Method: A cross-sectional, and quantitative and comparative approach study was carried out in the months of July and August 2022. A convenience sample of 1.376 adolescents who responded to a self-report on child abuse was analyzed. To compare both groups (men and women), the Mann-Whitney U-test for Bayesian independent samples was used. Results: Among the various forms of child maltreatment, only was found in favor and with high evidence as alternative hypothesis, the emotional maltreatment (BF10=190.38; δ=0.31; 95 % CI: 0.20-0.48). This difference was higher in females (M=8.28) compared to males (M=7.09). In emotional and physical neglect, strong evidence was reported for the null hypothesis. Robust Bayes factor analysis confirmed the same results. Conclusions: Emotional maltreatment occurs mostly in adolescent females, being the gender that requires more psychological support. In the other forms of maltreatment, no differences were found in correspondence with gender. Consequently, health professionals should consider the role of gender in emotional maltreatment, but should not neglect the other forms of child maltreatment, emphasizing the specific particularities of each case.

Introdução: O abuso infantil é um problema psicológico frequente em crianças e adolescentes em todo o mundo. A exposição a vários tipos de abuso pode levar a outros problemas psicológicos e físicos, tornando-se necessário identificar qual tipo de abuso tem maior probabilidade de afetar homens e mulheres. Objetivo: Analisar as diferenças no abuso infantil de acordo com o sexo em adolescentes peruanos. Método: Estudo transversal, abordagem quantitativa e comparativa realizado nos meses de julho e agosto de 2022. Foi analisada uma amostra de conveniência de 1.376 adolescentes, que responderam a um autorrelato sobre abuso infantil. Para comparar os dois grupos, foi utilizado o teste U de Mann-Whitney para amostras independentes bayesianas. Resultados: Entre os vários tipos de abuso infantil, foram encontradas evidências a favor da hipótese alternativa apenas no abuso emocional (BF10=190,38; δ=0,31; IC 95%: 0,20-0,48), com evidências muito fortes. Essa diferença foi maior nas mulheres (M=8,28) em relação aos homens (M=7,09). Na negligência emocional e física, fortes evidências foram relatadas para a hipótese nula. A análise fatorial robusta de Bayes confirmou os mesmos resultados. Conclusões: O abuso emocional ocorre maioritariamente em mulheres adolescentes, sendo o género que mais requer apoio psicológico neste tipo de abuso infantil. Nos outros tipos de abuso, não foram encontradas diferenças quanto ao sexo. Consequentemente, os profissionais de saúde devem considerar o papel do gênero no abuso emocional, mas não negligenciar outros tipos de abuso infantil, enfatizando as especificidades de cada caso.

Added value of PET Bayesian penalized likelihood reconstruction algorithm in the diagnosis of solitary pulmonary nodules/masses / 中华核医学与分子影像杂志

Objective:To investigate the effects of silicon photomutipliers (SiPM) detector and Bayesian penalized likelihood (BPL) reconstruction algorithm on semiquantitative parameters of 18F-FDG PET/CT and diagnostic efficiency for solitary pulmonary nodules/masses compared with traditional photomultiplier tube (PMT) and ordered subsets expectation maximization (OSEM). Methods:From March 2020 to January 2022, 118 patients (76 males, 42 females, age (63.0±10.1) years) newly diagnosed with solitary pulmonary nodules/masses in First Hospital of Shanxi Medical University were prospectively enrolled and underwent 18F-FDG PET/CT imaging with two different PET/CT scanners successively. The images were divided into PMT+ OSEM, SiPM+ OSEM and SiPM+ BPL groups according to PET detector and reconstruction algorithms. The SUV max, SUV mean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of pulmonary nodules/masses were measured, then signal-to-noise ratio (SNR) and signal-to-background ratio (SBR) were calculated. One-way analysis of variance and Kruskal-Wallis rank sum test were performed to compare differences of above parameters among groups. ROC curve analysis was used to analyze the optimal threshold of SUV max for the differential diagnosis of pulmonary nodules/masses and AUCs were obtained. Results:There were 83 malignant nodules and 35 benign nodules. The image quality of SiPM+ BPL group (4.23±0.64) was better than that of SiPM+ OSEM group (3.57±0.50) or PMT+ OSEM group (3.58±0.51; F=54.85, P<0.001). There were significant differences in SUV max (7.57(3.86, 15.61) vs 4.95(2.22, 10.48)), SUV mean (4.43(2.28, 9.12) vs 2.84(1.21, 5.71)), MTV (3.54(1.57, 7.67) vs 5.09(2.83, 11.79)), SNR (28.12(12.55, 54.38) vs 20.16(8.29, 41.45)) and SBR (4.03(1.83, 7.75) vs 2.32(0.96, 5.03)) between SiPM+ BPL and SiPM+ OSEM groups ( H values: 16.63-37.05, all P<0.001). The optimal threshold values of SUV max in SiPM+ BPL, SiPM+ OSEM and PMT+ OSEM were 3.31, 2.21, 2.05 with AUCs of 0.686, 0.689, 0.615 for nodules < 2 cm, and were 10.29, 6.49, 4.33 with AUCs of 0.775, 0.782, 0.774 for nodules/masses ≥2 cm. Conclusions:Image quality and parameters of pulmonary nodules/masses are mainly affected by the reconstruction algorithms. BPL can improve SUV max, SUV mean, SBR and SNR, but reduce MTV without significant effect on liver parameters. SiPM+ BPL has a higher diagnostic threshold of SUV max than SiPM+ OSEM and PMT+ OSEM.

Dedução, Indução e a Arte do Raciocínio Clínico na Educação Médica: Revisão Sistemática e Proposta Bayesiana / Deduction, Induction and the Art of Clinical Reasoning in Medical Education: Systematic Review and Bayesian Proposal

Resumo Fundamento O raciocínio clínico está no centro da prática médica e emaranhado em uma confusão conceitual.A teoria da dualidade da probabilidade permite analisar seus aspectos objetivos e subjetivos. Objetivos Fazer revisão sistemática da literatura sobre o raciocínio clínico para tomada de decisão na educação médica e uma proposta chamada "Pensamento Conforme a Regra de Bayes" (PCRB). Métodos A revisão sistemática foi realizada na base PubMed até a data de 27/02/2022, seguindo metodologia rigorosa, por pesquisador experiente em revisão sistemática. A proposta PCRB, apresentada na discussão, foi elaborada no trabalho de conclusão de graduação em Filosofia na Universidade Federal de Minas Gerais. Usou-se a insuficiência cardíaca como exemplo. Resultados De 3340 artigos encontrados, incluíram-se 154 artigos: 24 tratando da condição de incerteza; 87 tratando de conceitos vagos (discussão de casos, heurística, lista de vieses cognitivos, escolha com sabedoria) incluídos sob o termo 'arte'; e 43 discutindo a ideia geral de raciocínio indutivo ou dedutivo. PCRB oferece regras de coerência e reprodutibilidade, inferência sob incerteza e regra de aprendizado, e pode, por meio da perspectiva subjetiva sobre a probabilidade, incorporar aqueles termos vagos classificados como 'arte', bem como argumentos e evidências. Conclusões A revisão sistemática mostra que o raciocínio é fundado na incerteza, predominantemente probabilístico; além de mostrar algumas possibilidades de erro do pensamento hipotético-dedutivo. O PCRB é um pensamento probabilístico em duas etapas que pode ser ensinado. A regra de Bayes é uma ferramenta linguística, uma regra geral de raciocínio, de diagnóstico, de comunicação científica e de revisão do conhecimento médico conforme novas evidências.

Abstract Background Clinical reasoning is at the core of medical practice and entangled in a conceptual confusion. The duality theory in probability allows to evaluate its objective and subjective aspects. Objectives To conduct a systematic review of the literature about clinical reasoning in decision making in medical education and to propose a "reasoning based on the Bayesian rule" (RBBR). Methods A systematic review on PubMed was conducted (until February 27, 2022), following a strict methodology, by a researcher experienced in systematic review. The RBBR, presented in the discussion section, was constructed in his undergraduate dissertation in Philosophy at Minas Gerais Federal University. Heart failure was used as example. Results Of 3,340 articles retrieved, 154 were included: 24 discussing the uncertainty condition, 87 on vague concepts (case discussion, heuristics, list of cognitive biases, choosing wisely) subsumed under the term "art", and 43 discussing the general idea of inductive or deductive reasoning. RBBR provides coherence and reproducibility rules, inference under uncertainty, and learning rule, and can incorporate those vague terms classified as "art", arguments and evidence, from a subjective perspective about probability. Conclusions This systematic review shows that reasoning is grounded in uncertainty, predominantly probabilistic, and reviews possible errors of the hypothetico-deductive reasoning. RBBR is a two-step probabilistic reasoning that can be taught. The Bayes theorem is a linguistic tool, a general rule of reasoning, diagnosis, scientific communication and review of medical knowledge according to new evidence.

Estrategia de predicción pacientes con casos de coronavirus; reporte de experiencia Pereira, Risaralda, marzo-abril 2020 / Prediction strategy for patients with coronavirus cases; experience report Pereira, Risaralda, March- April 2020

Resumen Introducción: la infección por COVID 19 corresponde actualmente al evento infeccioso con mayor impacto en salud púbica a nivel mundial, en Colombia, al 30 de abril de 2020 se registraron 6465 casos acumulados, 360 defunciones y 2186 casos recuperados, dado el aumento en los casos reportados mediante los sistemas de vigilancia epidemiológica se precisa de herramientas que faciliten el diagnóstico oportuno y la predicción en el comportamiento de los casos a nivel nacional. Objetivos: proponer un modelo estadístico que permita predecir la probabilidad de cursar con diagnóstico de COVID-19 en la población atendida por sospecha de infección por el mismo en una institución de tercer nivel del municipio de Pereira- Risaralda entre marzo y abril de 2020. Materiales y métodos: se presenta un estudio descriptivo de corte trasversal en el cual se analizaron 82 casos, se realizó un modelo predictivo basado en compuertas lógicas AND y OR, y análisis por estadística descriptiva e inferencial. Resultados: de los 82 registros analizados se encontró una relación hombre: mujer de 1:2; el 6% de los pacientes tuvo alta probabilidad para diagnóstico de COVID 19, el 20% tuvo probabilidad intermedia y el 72% registró baja probabilidad para COVID19, la concordancia del modelo con los resultados de las pruebas fue inferior a 0,5. Conclusiones: el modelo estadístico planteado fue insuficiente para lograr la predicción de la totalidad de los casos de COVID-19 basados en el perfil de riego de la población, se precisan nuevas investigaciones con tamaños de muestra superiores, diseños y análisis distintos. MÉD.UIS.2022;35(1): 57-69.

Abstract Introduction: COVID 19 infection currently corresponds to the infectious event with the greatest impact on public health worldwide, in Colombia, as of April 30, 2020, 6465 accumulated cases, 360 deaths and 2186 recovered cases were registered, given the increase in cases reported through epidemiological surveillance systems, tools are needed to facilitate timely diagnosis and prediction in the behavior of cases at the national level. Objectives: to propose a statistical model that allows predicting the probability of a diagnosis of COVID-19 in the population treated for suspected coronavirus infection in a third-level institution in the population of Pereira-Risaralda between March and April 2020. Materials and methods: a descriptive cross-sectional study is presented, in which 82 cases were analyzed, a predictive model based on AND and OR logic gates, analyzes by descriptive and inferential statistics were performed. Results: of the 82 records analyzed, a male: female ratio of 1: 2 was found; 6% of the patients had a high probability for the diagnosis of COVID 19, 20% had an intermediate probability and 72% had a low probability for COVID19, the agreement of the model with the test results was less than 0.5. Conclusions: the proposed statistical model was insufficient to achieve the prediction of all the cases of COVID-19 based on the irrigation profile of the population. New investigations are required with larger sample sizes associated with longitudinal designs and combined statistical analyzes that allow to refine the proposed model. MÉD.UIS.2022;35(1): 57-69.

El Enfoque Bayesiano en las Ciencias de la Salud / The Bayesian Approach in the Health Sciences

En estadística existen dos enfoques básicos, la estadística frecuentista que es la corriente principal y la estadística bayesiana. La mayoría de los principales métodos estadísticos son frecuentistas siendo el enfoque bayesiano más desconocido entre los investigadores. En el presente artículo se exponen los fundamentos lógicos del enfoque bayesiano y su uso mediante un ejemplo de aplicación. En este contexto, más que presentar un debate entre la lógica clásica y la bayesiana, se pretende mostrar de manera introductoria las enormes posibilidades que el enfoque bayesiano puede aportar a la investigación en las Ciencias de la Salud.

In the stadistic field there are two basic approaches, the Frequentist Statistics which is the primary one, and the Bayesian Statistics. The most used statistical methods are the Frequentist methods, being the Bayesian approach the most popular among researchers. In this article, the logical basis of the Bayendian approach and its use are exposed through an application example. In this context, rather than presenting a debate between the classic and the Bayensian logic, it is intended to demonstrate in an introductory method the considerable possibilities how Bayesian approach can contribute to Health and Sciences research.

Clinical efficacy and safety of ex-vivo liver resection and liver auto-transplantation: a bayesian single-arm Meta-analysis / 中华肝胆外科杂志

Objective:To evaluate the clinical efficacy and safety of ex vivo liver resection and autotransplantation (ELRA) by using a Bayesian single-arm Meta-analysis.Methods:Databases of PubMed, Embase, Cochrane Library, Web of Science, CNKI, and Wanfang were searched from January 1, 1990 to December 30, 2021 on ELRA studies. The Bayesian one-arm Meta-analysis was performed by using the statistical software of R (V4.1.2) and the Markov chain-Monte Carlo method was used to simulate the posterior distribution. The mortality rate within 30 days after operation, 1-year survival rate, major postoperative complications, R 0 resection rate and other related indexes were analyzed. Results:A total of 20 studies with 436 patients were included. Bayesian single-arm Meta-analysis showed that the 1-year survival rate after ELRA was 83.24% [95% highest posterior density ( HPD): 72.40%-92.05%]. The 1-year survival rates after surgery were 88.66% (95% HPD: 81.52%-94.50%) for patients with hepatic alveolar echinococcosis and 61.29% (95% HPD: 38.53%-93.68%) for patients with hepatic malignancies, respectively. The mortality rate within 30 d after surgery, the incidence of significant postoperative complications, and the R 0 resection rate were 6.96% (95% HPD: 4.47%-10.15%), 27.91% (95% HPD: 19.00%-38.30%), and 99.84% (95% HPD: 37.61%-100.00%), respectively. Renal failure was the most frequent cause of death after ELRA. Conclusion:ELRA is indicated for hepatic malignancies and hepatic alveolar echinococcosis when intrahepatic resection cannot be accomplished in vivo. The greatest benefit is observed in patients with hepatic alveolar echinococcosis, while only some patients with hepatic malignancies can benefit. The indications for ELRA for hepatic malignancies need to be further studied to define the subgroup of patients who can benefit from this operation.

Minería de datos para la evaluación del riesgo de malignidad en pacientes con nódulos tiroideos con estudio citológico Bethesda IV / Risk of malignancy evaluation through data mining technic in patients with thyroid nodules with cytology study Bethesda IV

Introducción: en el campo de la salud, cada decisión representa datos, y las técnicas de minería de datos han empezado a ser una metodología prometedora para el análisis de esta información, especialmente en el diseño de los modelos predictivos. Métodos: estudio observacional analítico de pacientes mayores de 15 años, con reporte de punción de aspiración con aguja fina con estudio Bethesda IV, sometidos a manejo quirúrgico en el Hospital de San José de Bogotá. Los datos recogidos de los pacientes se incluyeron en tres grupos: la información sociodemográfica y clínica, los hallazgos en la citología y los reportes de la ecografía. Se realizó el análisis mediante Naive-Bayes, árbol de decisión y redes neuronales. Se usó la herramienta Weka versión 3.8.2. Resultados: de los 427 pacientes, 195 tuvieron resultados de patología de carcinoma de tiroides (45,6 %). Se evidenciaron mejores resultados usando la validación cruzada (10 fold) comparado con partición (66 %), la técnica de Bayes tuvo mejores resultados de clasificación correcta (91,1 %), comparado con la técnica de árbol (87,8 %) y la red neuronal (88,2 %). Conclusiones: el uso de la técnica de Naive Bayes muestra una importante exactitud para determinar la predicción de riesgo de malignidad en los pacientes con estudio citológico Bethesda IV, lo cual permitiría orientar de forma adecuada el manejo quirúrgico de los pacientes

Introduction: In the health field, each decision represents data, and data mining techniques have begun to be a promising methodology for the analysis of this information, especially in the design of predictive models. Methods: Analytical observational study; patients older than 15 years with a report of Bethesda IV after a fine needle aspiration biopsy that undergoing surgical management at the Hospital de San José in Bogotá. The data collected from those patients were included in three groups: sociodemographic-clinical information, cytology findings, and ultrasound reports. Analysis was performed using three technics: Naive Bayes, decision trees, and neural networks. Weka tool version 3.8.2 was used. Results: 195 patients out of 427, had a thyroid carcinoma pathology (45.6%). Better results were evidenced using cross-validation (10 fold) compared with a partition (66%), the Bayes technique had better results of correct classification (91.1%), than the tree technique (87.8%) and neural network (88.2%). Conclusions: The use of the Naive Bayes technique shows an important accuracy to determine the prediction of risk of malignancy in patients with a Bethesda IV cytological study, which would allow an adequate guide to the surgical management of patients.

Análisis lineal y no lineal de la variabilidad de la frecuencia cardíaca a corto plazo en pacientes con enfermedad arterial coronaria / Linear and nonlinear analysis of short-term heart rate variability in patients with coronary artery disease

Introducción. La variabilidad de la frecuencia cardíaca (HRV, por su sigla en inglés) a corto plazo es un parámetro fisiológico que se asocia a la salud cardiovascular y se ha utilizado en el manejo de la enfermedad arterial coronaria (EAC) para caracterizar dinámicas cardiovasculares y para evaluar el efecto de intervenciones terapéuticas. Objetivos. Caracterizar la HRV a corto plazo en pacientes con EAC a través de medidas lineales y no lineales, y evaluar el efecto de potenciales terceras variablessobre la HRV en el grupo de estudio. Métodos. Estudio observacional analítico en el que se revisaron las historias clínicas de 24 pacientes con EAC y un promedio de edad de 60,1±7,11 años. Los intervalos RR se registraron en reposo con un monitor Polar H7 durante 15 minutos. El análisis lineal se efectuó con parámetros en el dominio del tiempo y la frecuencia, y el no lineal, con la entropía muestral (SampEn) y el gráfico de Poincaré; también se incluyeron los índices autonómicos y se realizó inferencia bayesiana para evaluar el efecto de terceras variables y la correlación entre los índices de la HRV. Resultados. El análisis lineal evidenció disminución de la HRV latido a latido, y el no lineal, de la variabilidad global. Los índices autonómicos sugirieron un balance simpático- agal positivo, con tendencia al incremento de la actividad simpática y disminución de la parasimpática. SampEn fue el parámetro que presentó menor dispersión y los índices espectrales en unidades logarítmicas evidenciaron correlación débil con algunas variables metabólicas. Conclusiones. La HRV permite caracterizar las dinámicas cardiovasculares en pacientes con EAC, incluyendo el balance autonómico; además, la aproximación no lineal ofrece una alternativa de medida sensible y potencialmente más robusta. No obstante, debe considerarse el efecto de algunas variables metabólicas en la asociación entre HRV y factores independientes.

Introduction. Short-term heart rate variability (HRV) is a physiological parameter associated with cardiovascular health and has been used in the management of coronary artery disease (CAD) to characterize cardiovascular dynamics and to evaluate the effect of therapeutic interventions. Objectives. To characterize short-term HRV in patients with CAD through linear and nonlinear measures, and to evaluate the effect of potential third variability on HRV in the study group. Methods. Analytical observational study in which the medical records of 24 patients with CAD and a mean age of 60.1±7.11 years were reviewed. RR intervals were recorded at rest with a Polar H7 monitor for 15 minutes. Linear analysis was performed with parameters in the time and frequency domain, and nonlinear analysis with sample entropy (SampEn) and Poincaré plot; autonomic indices were also included and Bayesian inference was performed to evaluate the effect of third variables and the correlation between HRV indices. Results. Linear analysis showed a decrease in HRV beat-to-beat, and nonlinear analysis showed a decrease in global variability. The autonomic indices suggested a positive sympathetic-agal balance, with a tendency to increase sympathetic activity and decrease parasympathetic activity. SampEn was the parameter that showed the least dispersion and the spectral indexes in logarithmic units showed weak correlation with some metabolic variables. Conclusions. HRV allows characterization of cardiovascular dynamics in patients with CAD, including autonomic balance; moreover, the nonlinear approach offers a sensitive and potentially more robust measurement alternative. Nevertheless, the effect of some metabolic variables on the association between HRV and independent factors should be considered.

Frequentist and Bayesian Hypothesis Testing: An Intuitive Guide for Urologists and Clinicians / Pruebas de hipótesis frecuentista y bayesiana: Una Guía intuitiva para urólogos y clínicos

Given the limitations of frequentist method for null hypothesis significance testing, different authors recommend alternatives such as Bayesian inference. A poor understanding of both statistical frameworks is common among clinicians. The present is a gentle narrative review of the frequentist and Bayesian methods intended for physicians not familiar with mathematics. The frequentist p-value is the probability of finding a value equal to or higher than that observed in a study, assuming that the null hypothesis (H0) is true. The H0 is rejected or not based on a p threshold of 0.05, and this dichotomous approach does not express the probability that the alternative hypothesis (H1) is true. The Bayesian method calculates the probability of H1 and H0 considering prior odds and the Bayes factor (Bf). Prior odds are the researcher's belief about the probability of H1, and the Bf quantifies how consistent the data is concerning H1 and H0. The Bayesian prediction is not dichotomous but is expressed in continuous scales of the Bf and of the posterior odds. The JASP software enables the performance of both frequentist and Bayesian analyses in a friendly and intuitive way, and its application is displayed at the end of the paper. In conclusion, the frequentist method expresses how consistent the data is with H0 in terms of p-values, with no consideration of the probability of H1. The Bayesian model is a more comprehensive prediction because it quantifies in continuous scales the evidence for H1 versus H0 in terms of the Bf and the

Dadas las limitaciones del método de significancia frecuentista basado en la hipótesis nula, diferentes autores recomiendan alternativas como la inferencia bayesiana. Es común entre los médicos una comprensión deficiente de ambos marcos estadísticos. Esta es una revisión narrativa amigable de los métodos frecuentista y bayesiano dirigida quienes no están familiarizados con las matemáticas. El valor de p frecuentista es la probabilidad de encontrar un valor igual o superior al observado en un estudio, asumiendo que la hipótesis nula (H0) es cierta. La H0 se rechaza o no con base en un umbral p de 0.05, y este enfoque dicotómico no expresa la probabilidad de que la hipótesis alternativa (H1) sea verdadera. El método bayesiano calcula la probabilidad de H1 y H0 considerando las probabilidades a priori y el factor de Bayes (fB). Las probabilidades a priori son la creencia del investigador sobre la probabilidad de H1, y el fB cuantifica cuán consistentes son los datos con respecto a H1 y H0. La predicción bayesiana no es dicotómica, sino que se expresa en escalas continuas del fB y de las probabilidades a posteriori. El programa JASP permite realizar análisis frecuentista y bayesiano de una forma simple e intuitiva, y su aplicación se muestra al final del documento. En conclusión, el método frecuentista expresa cuán consistentes son los datos con H0 en términos de valores p, sin considerar la probabilidad de H1. El modelo bayesiano es una predicción más completa porque cuantifica en escalas continuas la evidencia de H1 versus H0 en términos del fB y de las probabilidades a posteriori.

Prevalencia bayesiana de Staphylococcus aureus en vacas lecheras en el Valle del Cauca, Colombia / Bayesian prevalence of Staphylococcus aureus in Valle del Cauca, Colombia dairy cows / Prevalência bayesiana de Staphylococcus aureus em vacas leiteiras no Vale do Cauca, Colômbia

Resumen El Staphylococcus aureus es uno de los principales microorganismos causantes de mastitis subclínica en las vacas lecheras. Determinar la prevalencia del S. aureus se hace necesario en vacas de hatos lecheros grandes y pequeños ubicados en la región norte, centro y sur del departamento del Valle del Cauca, Colombia. Se utilizó la metodología del National Mastitis Council recolectando 1070 muestras de leche de 273 vacas en 17 hatos mediante un muestreo polietápico, durante el periódo 2015 - 2016. Se realizó cultivo con todas las muestras recolectadas independientemente del resultado de la prueba de California mastitis test. Se utilizó el análisis bayesiano de los datos para obtener estimaciones más precisas. La prevalencia bayesiana del patógeno S. aureus en vacas lecheras en el Valle del Cauca fue de 31,94% y se tiene un 95% de probabilidad de que el intervalo (30,03 - 37,62%) contenga el valor de dicha prevalencia. La región Norte, Centro y Sur evidenciaron prevalencias de 33%, 34% y 24% respectivamente. En cuanto al tamaño del hato se evidenció que las vacas de los hatos pequeños presentan mayor prevalencia con 47% que las vacas de los hatos grandes 17% a la presencia del patógeno. La alta prevalencia encontrada en las vacas genera un alto impacto en la salud pública debido a una posible contaminación zoonótica por este patógeno.

Abstract Staphylococcus aureus is one of the main microorganisms responsible of subclinical mastitis in dairy cows. To determine the bayesian prevalence of S. aureus of cows in large and small dairy farms located in the northern, central and southern region of the Valle del Cauca province in Colombia. We Followed the National Mastitis Council methodology, 1070 milk samples from 273 cows in 17 dairy farms by means of a multi-stage sampling, were collected during the period 2015-2016. Cultivation was carried out with all the samples. Bayesian inference was used. The prevalence of the pathogen S. aureus in dairy cows in Valle del Cauca is 31,94% and there is a 95% probability that the interval (30,03 - 37,62%). The North, Central and South regions showed prevalence values of 33%, 34% and 24% respectively. Small dairy farms have prevalence, 47%, large dairy farms 17%. The high prevalence found in the cows studied generates a high impact on public health due to possible zoonotic contamination by this pathogen.

Resumo O Staphylococcus aureus é um dos principais microrganismos causadores de mastite subclínica em vacas leiteiras. Determinar a prevalência de S. aureus em vacas de leite em pequenas e grandes rebanhos leiteiros localizados região no norte, centro e sul do estado do Valle del Cauca, Colômbia. A metodologia do Conselho Nacional de Mastite 1070 foi utilizado para coletar amostras de leite de 273 vacas em 17 rebanhos através de amostragem de vários estágios durante o período 2015 - 2016. O cultivo foi realizado com todas as amostras coletadas, independentemente do resultado do teste de mastite Califórnia. O análise Bayesiana dos dados foi utilizada para obter estimativas mais precisas. Bayesian prevalência de agentes patogénicos S. aureus em vacas leiteiras no Valle foi 31,94% e tem uma probabilidade de 95% com um intervalo 30,03% - 37,62%. As regiões Norte, Central e Sul apresentaram prevalências de 33%, 34% e 24%, respectivamente. Em relação ao tamanho do rebanho, ficou evidente que as vacas dos pequenos rebanhos apresentam maior prevalência do patogeno com 47% comparado com 17% nas vacas dos grandes rebanhos. A alta prevalência encontrada nas vacas estudadas gera alto impacto na saúde pública, agravado pelo fato de metade do leite consumido na Colômbia ser cru.

Síndrome de Bayés en el perioperatorio / Bayes syndrome in the perioperative period

Resumen: Los bloqueos auriculares se caracterizan por alteraciones en la conducción secundarias a un retardo o bloqueo en el haz de Bachmann. El Dr. Antonio Bayés de Luna fue uno de los primeros en describir de manera extensa esta entidad a partir de 1979, clasificándolo en inter- e intraauriculares. El bloqueo interauricular se caracteriza en el electrocardiograma (ECG) por onda P con duración mayor a 120 mseg y que presentan morfología bimodal, especialmente en las derivaciones DI, DII, aVL y en las derivaciones inferiores. Existen varios tipos y grados de bloqueo interauricular relacionados a la magnitud del deterioro de la conducción entre las aurículas. Este bloqueo se asocia con frecuencia a taquiarritmias, en especial fibrilación auricular. El manejo incluye antiarrítmicos, anticoagulantes y, en casos especiales, terapia de resincronización auricular. El objetivo de este trabajo es enfatizar en la importancia de la evaluación de la onda P y de los bloqueos interauriculares en el período perioperatorio.

Abstract: The interatrial block is an auricular conduction abnormality secondary to delay or block through the Bachmann's bundle. Dr. Antonio Bayés de Luna was the first who provided a clear description of atrial conduction block in 1979, classifying them into either inter- and -intra atrial. The interatrial block is expressed in the electrocardiogram (ECG) by the presence of P-wave duration that equals or exceeds 120 mseg and presents usually a bimodal morphology, especially in leads I, II, aVL and inferior leads. There are different types of interatrial block related to deterioration of conduction between the right and left atrium. It was demonstrated that this type of block is very frequently accompanied by paroxysmal atrial arrhythmia, especially atrial fibrillation. Current medical therapies included anti-arrythmic, anticoagulation and in special cases atrial resynchronization. The aim of this paper is to emphasize the importance of the evaluation of P wave and interatrial blocks in the perioperative period.

Análisis bayesiano de la ideación suicida en adultos peruanos / Bayesian analysis of the suicidal idea in Peruvian adults

Introducción: La ideación suicida es un término amplio para describir una variedad de contemplaciones, deseos y preocupaciones sobre la muerte. Es uno de los principales factores de riesgo de muerte por suicidio, aunque se refieren diferencias en cuanto al sexo. Objetivo: Analizar las diferencias según el sexo respecto a la ideación suicida en adultos peruanos. Métodos: Se efectuó un estudio comparativo, transversal y no experimental, durante abril del 2021, de 366 adultos peruanos de la población general, seleccionados mediante muestreo por conveniencia a través de criterios de inclusión y exclusión. A tal efecto, se utilizaron el inventario de frecuencia de ideación suicida y, en el análisis estadístico, la prueba de la U de Mann-Whitney de muestras independientes bayesianas. Resultados: El promedio de edad fue de 29,64 años y existió una mayor participación del sexo femenino (55,5 %). El análisis bayesiano demostró que los datos observados eran más probables bajo la hipótesis alternativa (BF10=53,477; δ=0,411; IC 95 %: 0,181-0,635), con una evidencia muy fuerte. Esta diferencia fue superior en las mujeres (M=6,46) en comparación con los hombres (M=5,83). Conclusiones: Los hallazgos demostraron que la ideación suicida se presenta principalmente en las mujeres, de manera que resulta el grupo más vulnerable y, por ende, necesita una mayor atención por parte de los profesionales de la salud. Al respecto, los psicólogos y psiquiatras desempeñan un papel importante en identificar a las personas en riesgo y proporcionar anticipadamente la ayuda necesaria para su intervención.

Introduction: The suicidal idea is a wide term to describe a variety of views, desires and concerns about death. It is one of the main risk factors of suicidal death, although they refer differences as for sex. Objective: To analyze the differences according to sex regarding the suicidal ideation in Peruvian adults. Methods: A comparative, cross-sectional and non-experimental study was carried out, in April, 2021, of 366 Peruvian adults from the general population, selected by means of sampling by convenience with inclusion and exclusion criteria. To such an effect, the frequency inventory of suicidal ideation, and in the statistical analysis, the Mann-Whitney U-test of independent bayesian samples were used. Results: The average age was 29.64 and there a higher participation of the female sex (55.5 %). The bayesian analysis demonstrated that the observed data were more probable under the alternative hypothesis (BF10=53.477; δ=0.411; IC 95 %: 0.181-0.635), with a very strong evidence. This difference was higher in women (M=6.46) in comparison with men (M=5.83). Conclusions: The findings demonstrated that suicidal ideation is mainly presented in women, so that it is the most vulnerable group, reason why it needs a higher care of health professionals. In this respect, psychologists and psychiatrists play an important role to identify people at risk and provide the necessary help in advance for their intervention.

Uso del factor Bayes durante el análisis estadístico: un ejemplo / Use of the Bayes factor during statistical analysis: an example

El factor de Bayes resulta una prueba recomendable para la comprobación de las hipótesis esta-dísticas atendiendo al estado de los p valores, empleando la escala de clasificación de Jeffreys preferiblemente

The Bayes factor is a recommended test for the verification of statistical hypotheses taking into account the state of the p values, preferably using the Jeffreys classification scale.

Síndrome de Bayes en un paciente con infarto agudo de miocardio

RESUMEN La activación del corazón se produce a partir de un conjunto de células especializadas, con capacidad de generar y conducir el impuslo eléctrico. Cuando la conducción hacia la aurícula izquierda solo sufre un retardo en su recorrido por el Haz de Bachman, se define como bloqueo interauricular parcial, sin embargo cuando se afecta de manera total es un bloqueo avanzado. Se presenta el caso de un hombre de 85 años de edad que acude al Cuerpo de Guardia del Hospital Manuel Fajardo por presentar un episodio de disnea intensa de aparición súbita, aparentemente debida a un sídrome coronario agudo. En un electrocardiograma evolutivo se constató la presencia de un bloqueo interauricular avanzado con una onda P > 120 ms e isodifásica en DII, DIII y aVF, y posteriormente fibrilación auricular. El tratamiento de esta arritmia y de las enfermedades de base en pacientes con síndrome de Bayes son, en la actualidad, la alternativa terapéutica más oportuna.

ABSTRACT Activation of the heart is produced by a group of specialized cells with the capacity of generating and conducting electrical impulses. When the conduction to the left atrium only suffers a delay in its path through the Bachman's bundle, it is defined as a partial interatrial block; however, when it is totally affected, it is an advanced block. We present the case of an 85-year-old man who came to the emergency room of the Hospital Manuel Fajardo for presenting an event of intense dyspnea of sudden onset, apparently due to acute coronary syndrome. An evolving electrocardiogram revealed the presence of advanced interatrial block with a P wave > 120 ms and isodiphasic in leads II, III and aVF, and later atrial fibrillation. The treatment for this arrhythmia and the underlying diseases in patients with Bayes syndrome is currently the most appropriate therapeutic alternative.

Small numbers are an opportunity, not a problem / Números pequenos são uma oportunidade, não um problema

Aims: outcomes of research in education and training are partly a function of the context in which that study takes place, the questions we ask, and what is feasible. Many questions are about learning, which involves repeated measurements in a particular time window, and the practical context is usually such that offering an intervention to some but not to all learners does not make sense or is unethical. For quality assurance and other purposes, education and training centers may have very locally oriented questions that they seek to answer, such as whether an intervention can be considered effective in their context of small numbers of learners. While the rationale behind the design and outcomes of this kind of studies may be of interest to a much wider community, for example to study the transferability of findings to other contexts, people are often discouraged to report on the outcomes of such studies at conferences or in educational research journals. The aim of this paper is to counter that discouragement and instead encourage people to see small numbers as an opportunity instead of as a problem. Method: a worked example of a parametric and a non-parametric method for this type of situation, using simulated data in the zero-cost Open Source statistical program R version 4.0.5. Results: contrary to the non-parametric method, the parametric method can provide estimates of intervention effectiveness for the individual participant, account for trends in different phases of a study. However, the non-parametric method provides a solution in several situations where the parametric method should be used. Conclusion: Given the costs of research, the lessons to be learned from research, and statistical methods available, small numbers should be considered an opportunity, not a problem.

Objetivo: os resultados da pesquisa em educação e treinamento são, em parte, uma função do contexto em que esse estudo ocorre, das perguntas que fazemos e do que é viável. Muitas perguntas são sobre a aprendizagem, que envolve medições repetidas em uma janela de tempo específica, e o contexto prático, geralmente, é tal, que oferecer uma intervenção a alguns, mas não a todos os alunos, não faz sentido ou é antiético. Para garantia de qualidade e outros propósitos, os centros de educação e treinamento podem ter perguntas orientadas localmente que procuram responder, como, por exemplo, se uma intervenção pode ser considerada eficaz em seu contexto de pequeno número de alunos. Embora a justificativa por trás do projeto e dos resultados deste tipo de estudos possa ser do interesse de uma comunidade muito mais ampla, por exemplo, para estudar a possibilidade de transferência de resultados para outros contextos, as pessoas são frequentemente desencorajadas a relatar os resultados de tais estudos em conferências ou em revistas de pesquisa educacional. O objetivo deste artigo é combater esse desânimo e, em vez disso, incentivar as pessoas a verem os pequenos números como uma oportunidade em vez de um problema. Método: realizado um exemplo de método paramétrico e não paramétrico para este tipo de situação, utilizando dados simulados no programa estatístico Open Source R versão 4.0.5 de custo zero. Resultados: ao contrário do método não paramétrico, o método paramétrico pode fornecer estimativas da eficácia da intervenção para o participante individual, levando em conta as tendências em diferentes fases de um estudo. No entanto, o método não paramétrico fornece uma solução em várias situações, onde o método paramétrico deve ser usado. Conclusão: dados os custos da pesquisa, as lições a serem aprendidas com a pesquisa e os métodos estatísticos disponíveis, pequenos números devem ser considerados uma oportunidade, não um problema.

Regression Imputation and Optimized Gaussian Naïve Bayes Algorithm for an Enhanced Diabetes Mellitus Prediction Model

Abstract Diabetes mellitus (DM) is a category of metabolic disorders caused by high blood sugar. The DM affects human metabolism, and this disease causes many complications like Heart disease, Neuropathy, Diabetic retinopathy, kidney problems, skin disorder and slow healing. It is therefore essential to predict the presence of DM using an automated diabetes diagnosis system, which can be implemented using machine learning algorithms. A variety of automated diabetes prediction systems have been proposed in previous studies. Even so, the low prediction accuracy of DM prediction systems is a major issue. This proposed work developed a diabetes mellitus prediction system to improve the diabetes mellitus prediction accuracy using Optimized Gaussian Naive Bayes algorithm. This proposed model using the Pima Indians diabetes dataset as an input to build the DM predictive model. The missing values of an input dataset are imputed using regression imputation method. The sequential backward feature elimination method is used in this proposed model for selecting the relevant risk factors of diabetes disease. The proposed machine learning classifier named Optimized Gaussian Naïve Bayes (OGNB) is applied to the selected risk factors to create an enhanced Diabetes diagnostic system which predicts Diabetes in an individual. The performance analysis of this prediction architecture shows that, over other traditional machine learning classifiers, the Optimized Gaussian Naïve Bayes achieves an 81.85% classifier accuracy. This proposed DM prediction system is effective as compared to other diabetes prediction systems found in the literature. According to our experimental study, the OGNB based diabetes mellitus prediction system is more appropriate for DM disease prediction.

Principios de estadística Bayesiana y su relación con la farmacocinética aplicada / Principles of Bayesian statistics and its relationship with applied pharmacokinetics

La metodología estadística Bayesiana permite, si se conoce la probabilidad poblacional de que un suceso ocurra, modificar su valor cuando se dispone de nueva información individual. Aunque las metodologías Bayesiana y frecuentista (clásica) tienen idénticos campos de aplicación, la primera se aplica cada vez más en investigación científica y análisis de big data. En la farmacoterapia moderna, la farmacocinética clínica ha sido responsable de la expansión de la monitorización, facilitada por desarrollos técnico-analíticos y matemático-estadísticos. La farmacocinética poblacional ha permitido identificar y cuantificar las características fisiopatológicas y de tratamiento en una población de pacientes determinada, en particular en pediatría y neonatología, y otros grupos vulnerables, explicando la variabilidad farmacocinética interindividual. Asimismo, la estimación Bayesiana resulta importante como herramienta estadística aplicada en programas informáticos de optimización farmacoterapéutica cuando la monitorización farmacológica se basa en la interpretación farmacocinética clínica. Aunque con ventajas y limitaciones, la optimización farmacoterapéutica basada en la estimación Bayesiana es cada vez más usada en la actualidad, siendo el método de referencia. Esto es particularmente conveniente para la práctica clínica de rutina debido al limitado número de muestras requeridas por parte del paciente, y a la flexibilidad en cuanto a los tiempos de muestreo de sangre para cuantificación de fármacos. Así, la aplicación de los principios Bayesianos a la práctica de la farmacocinética clínica resulta en la mejora de la atención farmacoterapéutica.

If one knows the probability of an event occurring in a population, Bayesian statistics allows mo difying its value when there is new individual information available. Although the Bayesian and frequentist (classical) methodologies have identical fields of application, the first one is increasin gly applied in scientific research and big data analysis. In modern pharmacotherapy, clinical phar macokinetics has been used for the expansion of monitoring, facilitated by technical-analytical and mathematical-statistical developments. Population pharmacokinetics has allowed the identification and quantification of pathophysiological and treatment characteristics in a specific patient popu lation, especially in the pediatric and neonatal population and other vulnerable groups, explaining interindividual variability. Likewise, Bayesian estimation is important as a statistical tool applied in pharmacotherapy optimization software when pharmacological monitoring is based on clinical phar macokinetic interpretation. With its advantages and despite its limitations, pharmacotherapeutic op timization based on Bayesian estimation is increasingly used, becoming the reference method today. This characteristic is particularly convenient for routine clinical practice due to the limited number of samples required from the patient and the flexibility it shows regarding blood sampling times for drug quantification. Therefore, the application of Bayesian principles to the practice of clinical phar macokinetics has led to the improvement of pharmacotherapeutic care.

Identification of activated pathways in lung adenocarcinoma based on network strategy

Background: Lung adenocarcinoma has increased incidence over the past years and is the cause for almost 50% of deaths attributable to lung cancer. The objective of this paper is to identify activated pathways associated with lung adenocarcinoma based on gene co-expression network analysis. Materials and Methods: Kyoto Encyclopedia of Genes and Genomes pathway analysis of dysregulated genes was performed based on Expression Analysis Systematic Explorer test to illuminate the biological pathways. Co-expression networks of lung adenocarcinoma in different tumor Stages (IA, IB, IIA, IIB, IIIA, IIIB, and IV) were constructed by Empirical Bayes approach to reweight gene pair scores. Pathway activity analysis was conducted to compute the distribution of pathways in different stages and to identify “activated” pathways in lung adenocarcinoma. Results: We evaluated 211 dysregulated genes between lung adenocarcinoma patients and normal controls. Pathway activity analysis was performed and P values of pathways, which obtained from co-expression networks (Stage IA, IB, IIA, IIB, IIIA, IIIB, and IV), were calculated. Cell cycle, progesterone-mediated oocyte maturation, and oocyte meiosis were activated during all stages in lung adenocarcinoma. Conclusions: We successfully identified three activated pathways (cell cycle, progesterone-mediated oocyte maturation, and oocyte meiosis) in different Stages (IA, IB, IIA, IIB, IIIA, IIIB, and IV) of lung adenocarcinoma

Características diferenciales del bloqueo interauricular avanzado típico y atípico / Differential characteristics of the typical and atypical advanced interatrial block

Resumen Objetivo: Se denomina bloqueo interauricular avanzado (BIA) a la existencia de una onda P ≥ 120 ms y bifásica +/- en las derivaciones inferiores (II-III-VF) del electrocardiograma (ECG) de superficie, el cual constituye un factor predictivo significativo del desarrollo de fibrilación auricular. En fecha reciente se han descrito cuatro patrones de BIA atípicos (BIA-At) con base en la morfología y la duración de la onda P, sin conocer si comparten patogenia y características clínicas similares. Método: Estudio observacional, descriptivo y retrospectivo de pacientes, visitados en el Servicio de Cardiología, en ritmo sinusal y con BIA. Las variables analizadas se obtuvieron de la historia clínica informatizada. El análisis de la onda P se efectuó al aumentar el tamaño del electrocardiograma y mediante calipers electrónicos. El análisis estadístico se realizó con SPSS 19.0, con nivel de significación de p < 0.05. Resultados: Se incluyó a 75 pacientes con media de edad de 74.4 ± 11.7 años, con 62.7% de varones. Se compararon los grupos de pacientes con BIA típico (BIA-T) y BIA-At. El primero se relacionó con la existencia de diabetes mellitus (p = 0.001), enfermedad renal crónica estadio ≥ 3 (p = 0.036), bloqueo auriculoventricular (p = 0.006) y una menor fracción de expulsión ventricular media (p = 0.025); no hubo diferencias respecto de la prevalencia de fibrilación auricular/flúter o accidente cerebrovascular. Sólo la diabetes se acompañó de riesgo de ser un BIA-T (OR: 6.4; p = 0.002; IC 95%: 2.0-21.1). Conclusiones: La diabetes mellitus constituye el único factor de riesgo de que un BIA sea típico. Los pacientes con BIA-T y BIA-At presentan similar prevalencia de fibrilación auricular y accidente cerebrovascular, por lo que son objeto de un mismo tratamiento clínico.

Abstract Objective: It is called advanced interatrial block (IAB) to the existence of a P wave ≥ 120 ms and biphasic ± in the lower leads II-III-VF of the surface electrocardiogram (ECG), which constitutes a significant predictive factor for the development of atrial fibrillation. Recently, four patterns of atypical aIAB (At-IAB) have been described based on the morphology and duration of the P wave, but it’s unknown if they share the same pathogenesis and clinical characteristics. Method: An observational, descriptive and retrospective study was performed with patients, visited in cardiology, who have a sinus rhythm and with aIAB. The analyzed variables were obtained from the computerized clinical history. The analysis of the P wave was made by increasing the size of the ECG and by electronic calipers. Statistical analysis was performed with SPSS 19.0; level of significance: p < 0.05. Results: A total of 75 patients with an average age of 74.4 ± 11.7 years and with a 62.7% males, were included. It was compared the group of patients with typical aIAB (T-aIAB) and with At-aIAB. The first one was associated with the existence of diabetes mellitus (p = 0.001), chronic kidney disease stage ≥ 3 (p = 0.036), atrioventricular block (p = 0.006) and a lower mean ventricular ejection fraction (p = 0.025); there were no differences regarding the prevalence of atrial fibrillation/flutter or stroke. Only diabetes was associated with the risk of T-aIAB (odds ratio: 6.4; p = 0.002; 95% confidence interval: 2.0-21.1). Conclusions: Diabetes mellitus is the only risk factor for an aIAB to be typical. Patients with T-aIAB and At-aIAB have a similar prevalence of atrial fibrillation and stroke, so they must follow the same clinical management.

Statistics for N = 1: a non-parametric Bayesian approach / Estatística para N = 1: uma abordagem Bayesiana não paramétrica

Research in education is often associated with comparing group averages and linear relations in sufficiently large samples and evidence-based practice is about using the outcomes of that research in the practice of education. However, there are questions that are important for the practice of education that cannot really be addressed by comparisons of group averages and linear relations, no matter how large the samples. Besides, different types of constraints including logistic, financial, and ethical ones may make larger-sample research unfeasible or at least questionable. What has remained less known in many fields is that there are study designs and statistical methods for research involving small samples or even individuals that allow us to address questions of importance for the practice of education. This article discusses one type of such situations and provides a simple coherent statistical approach that provides point and interval estimates of differences of interest regardless of the type of the outcome variable and that is of use in other types of studies involving large samples, small samples, and single individuals.

A pesquisa em educação é frequentemente associada à comparação de médias de grupo e relações lineares em amostras suficientemente grandes, e a prática baseada em evidências trata do uso dos resultados dessa pesquisa na prática educacional. No entanto, há questões importantes para a prática da educação que não podem ser realmente abordadas por comparações de médias de grupo e relações lineares, por maiores que sejam as amostras. Além disso, diferentes tipos de restrições, incluindo as logísticas, financeiras e éticas, podem tornar a pesquisa com amostras maiores inviável ou, pelo menos, questionável. O que tem ficado menos conhecido em muitos campos é que existem desenhos de estudos e métodos estatísticos para pesquisas envolvendo pequenas amostras ou mesmo indivíduos que nos permitem abordar questões de importância para a prática da educação. Este artigo discute um tipo de tais situações e fornece uma abordagem estatística coerente simples que fornece estimativas de ponto e intervalo de diferenças de interesse, independentemente do tipo de variável de resultado e que é útil em outros tipos de estudos envolvendo grandes amostras, pequenas amostras, e indivíduos solteiros.