Manual de estadística avanzada en medicina

Para llevar a cabo un estudio de investigación clínica vamos a necesitar: • Saber elegir el tipo de estudio adecuado a lo que queremos realizar. • Tener los conocimientos estadísticos necesarios para llevar a cabo el estudio. • Saber utilizar un programa estadístico para manejar, analizar y representar los datos del estudio. • Y fundamentalmente, tiempo. El objetivo del presente manual es darle solución a los tres primeros puntos anteriores. Desgraciadamente el factor tiempo es una variable no modificable y va a depender del propio investigador. Para ello vamos en primer lugar a conocer las principales características del programa estadístico más utilizado que es SPSS. Aprenderemos a familiarizarnos con el programa y a adquirir un manejo fluido del mismo. Posteriormente se detallarán las principales herramientas estadísticas para analizar cualquier estudio, aumentando la complejidad de las mismas a medida que vayamos avanzando. El manual está pensado para que sea lo más práctico posible, sin laboriosas y complicadas explicaciones, detallando paso a paso cómo obtener los resultados de los ejemplos. Debe servir como manual de consulta para cuando queramos hacer cualquier estudio, pues lógicamente las cosas se olvidan y vamos a necesitar un documento recordatorio con los pasos necesarios en cada caso.To carry out a clinical research study, we will need: • Know how to choose the type of study appropriate to what we want to do. • Have the statistical knowledge necessary to carry out the study. • Know how to use a statistical program to manage, analyze and represent the study data. • And fundamentally, time. The objective of this manual is to solve the first three points above. Unfortunately, the time factor is a non-modifiable variable and will depend on the researcher himself. To do this, we will first of all know the main characteristics of the most used statistical program that is SPSS. We will learn to familiarize ourselves with the program and to acquire a fluid management of it. Later, the main statistical tools will be detailed to analyze any study, increasing the complexity of them as we progress. The manual is designed to be as practical as possible, without laborious and complicated explanations, detailing step by step how to obtain the results of the examples. It should serve as a reference manual for when we want to do any study, because logically things are forgotten and we will need a reminder document with the necessary steps in each case

Manual de estadística avanzada en medicina

Para llevar a cabo un estudio de investigación clínica vamos a necesitar: • Saber elegir el tipo de estudio adecuado a lo que queremos realizar. • Tener los conocimientos estadísticos necesarios para llevar a cabo el estudio. • Saber utilizar un programa estadístico para manejar, analizar y representar los datos del estudio. • Y fundamentalmente, tiempo. El objetivo del presente manual es darle solución a los tres primeros puntos anteriores. Desgraciadamente el factor tiempo es una variable no modificable y va a depender del propio investigador. Para ello vamos en primer lugar a conocer las principales características del programa estadístico más utilizado que es SPSS. Aprenderemos a familiarizarnos con el programa y a adquirir un manejo fluido del mismo. Posteriormente se detallarán las principales herramientas estadísticas para analizar cualquier estudio, aumentando la complejidad de las mismas a medida que vayamos avanzando. El manual está pensado para que sea lo más práctico posible, sin laboriosas y complicadas explicaciones, detallando paso a paso cómo obtener los resultados de los ejemplos. Debe servir como manual de consulta para cuando queramos hacer cualquier estudio, pues lógicamente las cosas se olvidan y vamos a necesitar un documento recordatorio con los pasos necesarios en cada caso.To carry out a clinical research study, we will need: • Know how to choose the type of study appropriate to what we want to do. • Have the statistical knowledge necessary to carry out the study. • Know how to use a statistical program to manage, analyze and represent the study data. • And fundamentally, time. The objective of this manual is to solve the first three points above. Unfortunately, the time factor is a non-modifiable variable and will depend on the researcher himself. To do this, we will first of all know the main characteristics of the most used statistical program that is SPSS. We will learn to familiarize ourselves with the program and to acquire a fluid management of it. Later, the main statistical tools will be detailed to analyze any study, increasing the complexity of them as we progress. The manual is designed to be as practical as possible, without laborious and complicated explanations, detailing step by step how to obtain the results of the examples. It should serve as a reference manual for when we want to do any study, because logically things are forgotten and we will need a reminder document with the necessary steps in each case

A 3’-UTR polymorphism in soluble epoxide hydrolase gene Is associated with acute rejection in renal transplant recipients

Antecedentes y finalidad: Los ácidos epoxyeicosatrienoic (EETs) son metabolitos del ácido araquidónico que desempeñan una función protectora contra procesos perjudiciales que pueden ocurrir después de re-oxigenación del injerto. Decidimos investigar si la presencia de polimorfismos funcionales en el gen que codifica el epóxido hidrolasa soluble (EPHX2), que metaboliza EETs a menos compuestos activos, pueden jugar un papel importante en el resultado del trasplante renal. Métodos En un grupo de 259 receptores caucásicos de trasplante renal y 183 donantes fallecidos, se determinó la presencia de tres EPHX2 común, a saber, los SNPs rs41507953 (K55R), rs751141 (R287Q) y rs1042032 A/G. Las asociaciones con los parámetros de la función del injerto y la incidencia de rechazo agudo fueron investigados retrospectivamente durante el primer año después del injerto mediante regresión logística, ajustándose a las variables clínicas y demográficas. Resultados Los portadores del genotipo rs1042032 GG muestran significativamente menor tasa de filtración glomerular estimada (eGFR) (38.15 ± 15.57 vs. 45.99 ± 16.05; p = 0,04) y mayores valores de creatinina sérica (1,57 ± 0,58 vs. 1,30 ± 0,47 g/dL; p=0.02) un año después del injerto, en comparación con los pacientes portadores del alelo A wildtype. El mismo genotipo GG también se asoció a un mayor riesgo de rechazo agudo. Curiosamente, esta asociación fue observada por el genotipo de ambos destinatarios [o =6.34 (1.35-29.90); p = 0,015] y donantes [OR = 5.53 (1.10 - 27.80); p=0,042]. Un modelo estadístico incluyendo ambos genotipos junto con otras variables demográficas y clínicas significativas se tradujo en un aumento de la importancia de la asociación con los receptores del genotipo [OR=8,28 (1.21-74.27); p=0,031]. Conclusiones Nuestros resultados indican que la variabilidad genética en el gen metabolizante de EETs, EPHX2, pueden tener un impacto significativo en los resultados del trasplante renal de donante fallecido.Background and Purpose: Epoxyeicosatrienoic acids (EETs) are arachidonic acid metabolites that play a protective role against damaging processes that may occur after re-oxygenation of the graft. We aimed to investigate whether the presence of functional polymorphisms in the gene encoding soluble epoxy hydrolase (EPHX2), which metabolizes EETs to less active compounds, may play a role in the outcome of renal transplantation. Methods In a group of 259 Caucasian renal transplant recipients and 183 deceased donors, we determined the presence of three common EPHX2 SNPs, namely rs41507953 (K55R), rs751141 (R287Q) and rs1042032 A/G. Associations with parameters of graft function and the incidence of acute rejection were retrospectively investigated throughout the first year after grafting by logistic regression adjusting for clinical and demographic variables. Results Carriers of the rs1042032 GG genotype displayed significantly lower estimated glomerular filtration rate (eGFR) (38.15 ± 15.57 vs. 45.99 ± 16.05; p = 0.04) and higher serum creatinine values (1.57 ± 0.58 vs. 1.30 ± 0.47 g/dL; p=0.02) one year after grafting, compared to patients carrying the wildtype A-allele. The same GG genotype was also associated to increased risk of acute rejection. Interestingly, this association was observed for the genotype of both recipients [OR =6.34 (1.35-29.90); p = 0.015] and donors [OR = 5.53 (1.10- 27.80); p=0.042]. A statistical model including both genotypes along with other meaningful demographic and clinical variables resulted in an increased significance for the association with the recipients’ genotype [OR=8.28 (1.21-74.27); p=0.031]. Conclusions Our results suggest that genetic variability in the EETs-metabolizing gene, EPHX2, may have a significant impact on the outcome of deceased-donor renal transplantation.• Asociación para el Estudio y la Prevención de las Enfermedades Renales (ASEPER), Badajoz • Junta de Extremadura, Consejería de Economía, Comercio e Innovación: Proyecto GR10022 • Red de Investigación Renal - REDINREN (Instituto de Salud Carlos III – Fondo Europeo de Desarrollo Regional – FEDER) : Ayudas a Eliecer Coto García, Carmen Díaz Corte y Carlos López LarreapeerReviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

Peer reviewe

Measurement of the W gamma Production Cross Section in Proton-Proton Collisions at root s=13 TeV and Constraints on Effective Field Theory Coefficients

A fiducial cross section for W gamma production in proton-proton collisions is measured at a center-of-mass energy of 13 TeV in 137 fb(-1) of data collected using the CMS detector at the LHC. The W -> e nu and mu nu decay modes are used in a maximum-likelihood fit to the lepton-photon invariant mass distribution to extract the combined cross section. The measured cross section is compared with theoretical expectations at next-to-leading order in quantum chromodynamics. In addition, 95% confidence level intervals are reported for anomalous triple-gauge couplings within the framework of effective field theory.Peer reviewe

Search for top squark production in fully hadronic final states in proton-proton collisions at root s=13 TeV

A search for production of the supersymmetric partners of the top quark, top squarks, is presented. The search is based on proton-proton collision events containing multiple jets, no leptons, and large transverse momentum imbalance. The data were collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 137 fb(-1). The targeted signal production scenarios are direct and gluino-mediated top squark production, including scenarios in which the top squark and neutralino masses are nearly degenerate. The search utilizes novel algorithms based on deep neural networks that identify hadronically decaying top quarks and W bosons, which are expected in many of the targeted signal models. No statistically significant excess of events is observed relative to the expectation from the standard model, and limits on the top squark production cross section are obtained in the context of simplified supersymmetric models for various production and decay modes. Exclusion limits as high as 1310 GeVare established at the 95% confidence level on the mass of the top squark for direct top squark production models, and as high as 2260 GeV on the mass of the gluino for gluino-mediated top squark production models. These results represent a significant improvement over the results of previous searches for supersymmetry by CMS in the same final state.Peer reviewe

Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at root s=13 TeV

Measurements of Higgs boson production cross sections and couplings in events where the Higgs boson decays into a pair of photons are reported. Events are selected from a sample of proton-proton collisions at root s = 13TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137 fb(-1). Analysis categories enriched in Higgs boson events produced via gluon fusion, vector boson fusion, vector boson associated production, and production associated with top quarks are constructed. The total Higgs boson signal strength, relative to the standard model (SM) prediction, is measured to be 1.12 +/- 0.09. Other properties of the Higgs boson are measured, including SM signal strength modifiers, production cross sections, and its couplings to other particles. These include the most precise measurements of gluon fusion and vector boson fusion Higgs boson production in several different kinematic regions, the first measurement of Higgs boson production in association with a top quark pair in five regions of the Higgs boson transverse momentum, and an upper limit on the rate of Higgs boson production in association with a single top quark. All results are found to be in agreement with the SM expectations.Peer reviewe

Measurements of the Electroweak Diboson Production Cross Sections in Proton-Proton Collisions at root s=5.02 TeV Using Leptonic Decays

The first measurements of diboson production cross sections in proton-proton interactions at a center-of-mass energy of 5.02 TeV are reported. They are based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 302 pb(-1). Events with two, three, or four charged light leptons (electrons or muons) in the final state are analyzed. The WW, WZ, and ZZ total cross sections are measured as sigma(WW) = 37:0(-5.2)(+5.5) (stat)(-2.6)(+2.7) (syst) pb, sigma(WZ) = 6.4(-2.1)(+2.5) (stat)(-0.3)(+0.5)(syst) pb, and sigma(ZZ) = 5.3(-2.1)(+2.5)(stat)(-0.4)(+0.5) (syst) pb. All measurements are in good agreement with theoretical calculations at combined next-to-next-to-leading order quantum chromodynamics and next-to-leading order electroweak accuracy