Berkson’s fallacy. Berkson’s fallacy is described, which occurs when we find a spurious association between two variables due to a improper sample.
Case-crossover studies. Case-crossover studies focus on the event and try to see something that favors it, comparing the exhibitions of immediate with previous moments.
Causality. Some causality models and some of their components are described: component cause, necessary cause and sufficient cause.
Hazard ratio. The hazard ratio represents the risk of presenting an event, with respect to the control group, in the next instant of time.
Crossover clinical trial. Crossover clinical trial allows each patient to receive the study and the control interventions, in a specific order and for a set time.