When the outcome variable is binary and it is possible to switch permanently from one state to another, we can carry out survival analyses This type of analysis can take into account the lost to follow-up The most commonly used statistical model for survival analysis in medical studies is...

When a parameter has not been measured for all patients in the study, we are talking about missing data There are few studies without missing data If missing data are present, they should be described and a strategy chosen to address them Missing data is a common problem in the...

Tests and statistical models all have conditions to be used.In this article, we describe the conditions of regression models, as well as how they are checked by pvalue.io Dans un effort de simplification, nous appellerons Y la variable que l'on souhaite expliquer par des facteurs X. (Faites appel à vos lointains...

When the outcome variable is binary and not censored, the appropriate statistical model is logistic regression; When there is only one explanatory variable which is qualitative, the logistic regression yields a result similar to a Chi2 test; In an attempt to simplify this, we will name Y the variable that...

When the outcome variable is quantitative and continuous, the appropriate statistical model is the linear regression When there is only one explanatory variable which is qualitative, linear regression yields a result close to a Welch or Student T test In an attempt to simplify this, we will name Y the variable that...

There are three types of analyses: descriptive analyses, univariate analyses and multivariate (or multivariable) analyses Descriptive analyses are used to describe the data, and are useful for detecting problems Univariate and multivariate analyses allow statistical comparisons (obtaining a p-value), and only multivariate analyses allow confounding factors to be taken into account Descriptive analyses Before...

It is sometimes surprising not to be able to carry out a multivariate analysis because the number of subjects is too small while the file contains several hundred observations (patients, subjects). Linear regressions For linear regressions, i. e. multivariate analyses for which the outcome variable is numerical, it is necessary to have...