Bayesian statistics is based on subjective probability. It works with evidence updating considering the knowledge acquired prior to an investigation, plus the evidence obtained thereof. Results' interpretation requires for the hypotheses to be tested to be specified and their a priori probability to be estimated before the study. Study evidence is measured with the Bayes factor (compatibility ratio of the data under the proposed hypotheses). The conjunction of hypotheses a priori probabilities with the Bayes factor allows calculating the a posteriori probability of each one of them. The hypothesis with the highest degree of certainty at its update is the one that is accepted for decision making. In this review, three examples of hypothesis to be tested are shown: difference of means, correlation and association.

Este artículo debe citarse como: Martínez-Ezquerro JD, Riojas-Garza A, Rendón-Macías MA. Significancia clínica sobre significancia estadística, como interpretar los intervalos de confianza a 95 %. Rev Med Alerg Mex. AbstractThe validity of a study depends on its proper planning, execution and analysis. If these are sufficiently correct, the decision to apply the recommendations issued depends on the expected clinical effect. This effect may have random variations, hence the need to use statistical inference. For years the p-value has been used to determine this statistical significance and the confidence intervals to measure the magnitude of the effect. In this review we present a proposal of how to interpret the 95 % confidence intervals (CI 95 %) as estimators of the expected effect variability based on considering the threshold or value of clinical significance and the null value of the difference or rejection of statistical significance. Thus, an association or effect where the CI 95 % includes the null value (no effect or difference) is interpreted as inconclusive; one between the null value and the clinical threshold (without including them) as possibly inconsequential; one that does not include the null value but the clinical threshold as yet not conclusive and one beyond the clinical threshold as conclusive.

Purpose: We analyzed the epidemiologic characteristics of different types of non-Hodgkin Lymphoma (NHL), excluding Burkitt Lymphoma, in 2 Mexican regions with different socioeconomic status. Materials and Methods: In this surveillance study, we analyzed the incidence rates (cases per million children/year) of different types of NHL according to the ICCC3, registered in 1996-2015, from 2 different socioeconomic regions in Mexico: central and southern, with higher and lower status, respectively. Results: The principal NHL subgroups were precursor (IIb1), mature B cell (IIb2), mature T/NK cell, and no other specification (NOS; 42.3%, 15.8%, 14.1%, and 27.8%, respectively). In both regions, the overall incidence rates were similar (central=5.3, 95% confidence interval [CI], 4.6-6.1 vs. southern=6.3, 95% CI, 4.6-8.4); also, there were no differences by types (precursor cell LNH, 2.3 vs. 2.5; mature B cell, 0.9 vs. 0.8; mature T/NK cells, 0.8 vs. 0.8; and NOS, 1.4 vs. 2.3). In both regions, a decreasing trend was found (central= −0.17%, 95% CI, −0.03 to −0.3, P=0.04; southern= −0.32%, 95% CI, −0.07 to −0.57, P=0.02), with major reduction of NHL NOS from 1996 to 2000. In both regions, men predominated (2.1:1). Conclusions: Socioeconomic status did not influence the incidence rates of NHL. In this study, we found a reduction of NHL NOS, possibly due to better typing.

ResumenObjetivo: Comparar el ultrasonido endoscópico (USE) en la valoración de los tumores ampulares primarios (TAp) con referencia al estudio histopatológico (HP). Método: Estudio retrospectivo prolectivo de pruebas diagnósticas en pacientes con TAp estadificados por USE y pancreatoduodenectomía con estudio HP, atendidos de 2012 a 2018 en un hospital de tercer nivel de atención. Resultados: Fueron incluidos14 pacientes con adenocarcinoma. El tamaño del tumor medido por USE mostró una adecuada correlación (R = 0.65; p = 0.01) con el HP. La exactitud en la determinación de la invasión a la pared duodenal, el páncreas y el conducto biliar fue del 78.5, el 78.5 y el 57.1%, respectivamente. Por HP hubo tres T1 (21.4%), dos T2 (14.2%) y nueve T3 (64.2%). La exactitud del estadiaje T y N por USE fue del 71.4% (kappa = 0.50) y del 50% (kappa = −0.04), respectivamente. Los errores en la estadificación fueron más frecuentes en los pacientes con prótesis biliar. Conclusión: El USE mostró utilidad en la determinación del tamaño tumoral y de la invasión al duodeno y al páncreas, y más limitada en la determinación de la invasión al conducto biliar por presencia de prótesis. Se observa una sobreestimación del estadiaje T y una subestimación del N. Es necesario mayor capacitación y sugerimos realizarse antes de colocar una prótesis biliar.