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.

DISTRIBUTION OF THE DICHOTOMIZING BRANCHES OF PERIPHERAL PROCESSES OF CAUDAL LUMBAR DORSAL ROOT GANGLION NEURONS IN THE RAT——A DOUBLE FLUORESCENCE LABELLING STUDY / 解剖学报

The technique of double labelling with fluorescent tracers(FB-NY,PI-Bb)has.been used in the following three groups of experiments:1.in 5 rats,one fluorescenttracer was injected into the tibial nerve and the other was injected into the peronealnerve;2.in 14 rats,one fluorescent tracer was injected into the sural cutaneousnerve and the other was injected into the branches to the soleus and gastrocnemiusmuscles;3.in 13 rats,one tracer was injected into the tibial nerve and the otherinto the bladder wall.The sections of the L_(3-6),S_(1-3) dorsal root ganglion were stu-died with a olympus fluorescence microscope using UG-1 excitation filter system.In the first and second groups,double labelled neurons were observed in L_(4-6) dorsalroot ganglion.But in the third group,the double labelled neurons were found onlyin the L_6 segment.The type of the double labelled neurons was mainly small-sized(33.1%)and small-medium sized(40.9%).The findings indicated that,the primary afferent fibers branched towards theperiphery and supplied,with different branches,either two somatic areas or skinand deep structures,or,especially,visceral and somatic sensory fields.This resultsuggests that the peripheral dichotomization of these dorsal root ganglion cells mightconverge sensory inputs from the somatic(tibial nerve)and the visceral(bladderwall)fields and thus provides one of the structural basis for the referred pain andthe neuronal mechanism of acupunctural therapy by which stimulation of somaticstructures could regulate the activities of visceral organs.