The meaning of p-value. The meaning of p-value is the probability of obtaining a value equal to or more distant from the equality of effect given that the null hypothesis is true.
Pitfalls of statistics. Some of the inappropriate uses of statistics are described, either due to ignorance or to modify the apparent relevance of the results.
The choice of the statistical test. The most suitable statistical test is described according to the type of variable, whether or not it is paired data and follow normal distribution. The most common situations will be those of comparison of means,…
Publication bias. We describe publication bias in meta-analysis and the most used methods that are empoyed for its study, both graphical and numerical.
Study of heterogeneity in meta-analysis. Numerical (Q, I, H) and graphical methods (Galbraith and L’Abbé) for the study of heterogeneity of the primary meta-analysis studies.