Category Epidemiology

Epidemiology, Statistics

The art of resignation

The procedure for choosing the cut-off point for a diagnostic test is reviewed. To decide this threshold, which is influenced by the characteristics of the model and the clinical scenario in which it will be applied, we will take into account the sensitivity and precision of the test for each possible cut-off point. The precision enrichment ratio will be useful in cases with a large imbalance between the two diagnostic categories.

Manuel Molina
01/30/2024

Epidemiology

An intruder from another world

The F1-score, also called F-score or F-measure, is an estimator of the classification capacity of a test that is frequently used in data science and artificial intelligence algorithms and that can be useful for evaluation of diagnostic tests. It is the harmonic mean of sensitivity and positive predictive value, so it weights the value of both in a single estimator.

Manuel Molina
11/06/2023

Epidemiology

From bridge to bridge

The concepts of odds and probability are described, as well as their combined use together with the Bayes’ factor for calculating the probability of being sick or healthy after knowing the result of a diagnostic test.

Manuel Molina
05/03/2022

Epidemiology

Like life itself

Pragmatic clinical trial. We all know how difficult it is to make a new drug available to people who can benefit from it. From the moment a promising molecule is identified and somebody thinks that it may be useful, until…

Manuel Molina
05/25/2021

Epidemiology

The tribulations of maturity

Correct use of NNT. The NNT was designed to assess the beneficial effect of a treatment to reduce the risk of an unpleasant event occurring in an intervention group of interest, always with respect to what was observed in a…

Manuel Molina
04/06/2021