Understanding probability

Concepts

Definition and properties of probability

It is important to know the basic properties and meaning of probability and especially the concept of conditional probability. Bayes' theorem, is fundamental to understand diagnostic tests and other applications.

Overview of health-related concepts that use probability

Prevalence, proportion, incidence, risk, and other important concepts in medicine are probabilities. Read this chapter to learn their definition, interpretation, and how to compute them in a practical situation.

Diagnostic tests: interpretation and relationship with probability

Diagnostic tests play a very important role in medicine. It is important to understand the probabilistic aspects related to these tests.

Simulators

Probability: definition and basic calculations

Probability and relative frequency (law of large numbers)

The relative frequency of an event in a sample is an approximation to the probability value. In this application, this relationship is studied.

Diagnostic tests

In this application, you should explore the properties of a diagnostic test and the relationship between sensitivity, specificity, prevalence and prognostic values. It is important to analyze different scenarios to understand the meaning and practical implications of these concepts.

FAQs

Usefulness of Bayes' theorem to calculate the probability of a disease as a function of a symptom

What are sensitivity and specificity?

What is the difference between sensitivity, specificity, false positives and false negatives?

What are the positive and negative prognostic values of a test?

How is a diagnostic criterion interpreted?

What is a ROC curve and what is it for?

How can we discriminate between various diseases based on a symptom?